From 1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 11 Jan 2020 23:36:56 +0000 Subject: Squashed 'third_party/git/' content from commit cb71568594 git-subtree-dir: third_party/git git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7 --- contrib/hooks/multimail/CHANGES | 285 ++ contrib/hooks/multimail/CONTRIBUTING.rst | 60 + contrib/hooks/multimail/README.Git | 15 + .../README.migrate-from-post-receive-email | 145 + contrib/hooks/multimail/README.rst | 774 ++++ contrib/hooks/multimail/doc/customizing-emails.rst | 56 + contrib/hooks/multimail/doc/gerrit.rst | 56 + contrib/hooks/multimail/doc/gitolite.rst | 118 + contrib/hooks/multimail/doc/troubleshooting.rst | 78 + contrib/hooks/multimail/git_multimail.py | 4346 ++++++++++++++++++++ contrib/hooks/multimail/migrate-mailhook-config | 274 ++ contrib/hooks/multimail/post-receive.example | 101 + contrib/hooks/post-receive-email | 759 ++++ contrib/hooks/pre-auto-gc-battery | 42 + contrib/hooks/setgitperms.perl | 214 + contrib/hooks/update-paranoid | 421 ++ 16 files changed, 7744 insertions(+) create mode 100644 contrib/hooks/multimail/CHANGES create mode 100644 contrib/hooks/multimail/CONTRIBUTING.rst create mode 100644 contrib/hooks/multimail/README.Git create mode 100644 contrib/hooks/multimail/README.migrate-from-post-receive-email create mode 100644 contrib/hooks/multimail/README.rst create mode 100644 contrib/hooks/multimail/doc/customizing-emails.rst create mode 100644 contrib/hooks/multimail/doc/gerrit.rst create mode 100644 contrib/hooks/multimail/doc/gitolite.rst create mode 100644 contrib/hooks/multimail/doc/troubleshooting.rst create mode 100755 contrib/hooks/multimail/git_multimail.py create mode 100755 contrib/hooks/multimail/migrate-mailhook-config create mode 100755 contrib/hooks/multimail/post-receive.example create mode 100755 contrib/hooks/post-receive-email create mode 100755 contrib/hooks/pre-auto-gc-battery create mode 100755 contrib/hooks/setgitperms.perl create mode 100755 contrib/hooks/update-paranoid (limited to 'contrib/hooks') diff --git a/contrib/hooks/multimail/CHANGES b/contrib/hooks/multimail/CHANGES new file mode 100644 index 000000000000..35791fd02c21 --- /dev/null +++ b/contrib/hooks/multimail/CHANGES @@ -0,0 +1,285 @@ +Release 1.5.0 +============= + +Backward-incompatible change +---------------------------- + +The name of classes for environment was misnamed as `*Environement`. +It is now `*Environment`. + +New features +------------ + +* A Thread-Index header is now added to each email sent (except for + combined emails where it would not make sense), so that MS Outlook + properly groups messages by threads even though they have a + different subject line. Unfortunately, even adding this header the + threading still seems to be unreliable, but it is unclear whether + this is an issue on our side or on MS Outlook's side (see discussion + here: https://github.com/git-multimail/git-multimail/pull/194). + +* A new variable multimailhook.ExcludeMergeRevisions was added to send + notification emails only for non-merge commits. + +* For gitolite environment, it is now possible to specify the mail map + in a separate file in addition to gitolite.conf, using the variable + multimailhook.MailaddressMap. + +Internal changes +---------------- + +* The testsuite now uses GIT_PRINT_SHA1_ELLIPSIS where needed for + compatibility with recent Git versions. Only tests are affected. + +* We don't try to install pyflakes in the continuous integration job + for old Python versions where it's no longer available. + +* Stop using the deprecated cgi.escape in Python 3. + +* New flake8 warnings have been fixed. + +* Python 3.6 is now tested against on Travis-CI. + +* A bunch of lgtm.com warnings have been fixed. + +Bug fixes +--------- + +* SMTPMailer logs in only once now. It used to re-login for each email + sent which triggered errors for some SMTP servers. + +* migrate-mailhook-config was broken by internal refactoring, it + should now work again. + +This version was tested with Python 2.6 to 3.7. It was tested with Git +1.7.10.406.gdc801, 2.15.1 and 2.20.1.98.gecbdaf0. + +Release 1.4.0 +============= + +New features to troubleshoot a git-multimail installation +--------------------------------------------------------- + +* One can now perform a basic check of git-multimail's setup by + running the hook with the environment variable + GIT_MULTIMAIL_CHECK_SETUP set to a non-empty string. See + doc/troubleshooting.rst for details. + +* A new log files system was added. See the multimailhook.logFile, + multimailhook.errorLogFile and multimailhook.debugLogFile variables. + +* git_multimail.py can now be made more verbose using + multimailhook.verbose. + +* A new option --check-ref-filter is now available to help debugging + the refFilter* options. + +Formatting emails +----------------- + +* Formatting of emails was made slightly more compact, to reduce the + odds of having long subject lines truncated or wrapped in short list + of commits. + +* multimailhook.emailPrefix may now use the '%(repo_shortname)s' + placeholder for the repository's short name. + +* A new option multimailhook.subjectMaxLength is available to truncate + overly long subject lines. + +Bug fixes and minor changes +--------------------------- + +* Options refFilterDoSendRegex and refFilterDontSendRegex were + essentially broken. They should work now. + +* The behavior when both refFilter{Do,Dont}SendRegex and + refFilter{Exclusion,Inclusion}Regex are set have been slightly + changed. Exclusion/Inclusion is now strictly stronger than + DoSend/DontSend. + +* The management of precedence when a setting can be computed in + multiple ways has been considerably refactored and modified. + multimailhook.from and multimailhook.reponame now have precedence + over the environment-specific settings ($GL_REPO/$GL_USER for + gitolite, --stash-user/repo for Stash, --submitter/--project for + Gerrit). + +* The coverage of the testsuite has been considerably improved. All + configuration variables now appear at least once in the testsuite. + +This version was tested with Python 2.6 to 3.5. It also mostly works +with Python 2.4, but there is one known breakage in the testsuite +related to non-ascii characters. It was tested with Git +1.7.10.406.gdc801, 1.8.5.6, 2.1.4, and 2.10.0.rc0.1.g07c9292. + +Release 1.3.1 (bugfix-only release) +=================================== + +* Generate links to commits in combined emails (it was done only for + commit emails in 1.3.0). + +* Fix broken links on PyPi. + +Release 1.3.0 +============= + +* New options multimailhook.htmlInIntro and multimailhook.htmlInFooter + now allow using HTML in the introduction and footer of emails (e.g. + for a more pleasant formatting or to insert a link to the commit on + a web interface). + +* A new option multimailhook.commitBrowseURL gives a simpler (and less + flexible) way to add a link to a web interface for commit emails + than multimailhook.htmlInIntro and multimailhook.htmlInFooter. + +* A new public function config.add_config_parameters was added to + allow custom hooks to set specific Git configuration variables + without modifying the configuration files. See an example in + post-receive.example. + +* Error handling for SMTP has been improved (we used to print Python + backtraces for legitimate errors). + +* The SMTP mailer can now check TLS certificates when the newly added + configuration variable multimailhook.smtpCACerts. + +* Python 3 portability has been improved. + +* The documentation's formatting has been improved. + +* The testsuite has been improved (we now use pyflakes to check for + errors in the code). + +This version has been tested with Python 2.4 and 2.6 to 3.5, and Git +v1.7.10-406-gdc801e7, 2.1.4 and 2.8.1.339.g3ad15fd. + +No change since 1.3 RC1. + +Release 1.2.0 +============= + +* It is now possible to exclude some refs (e.g. exclude some branches + or tags). See refFilterDoSendRegex, refFilterDontSendRegex, + refFilterInclusionRegex and refFilterExclusionRegex. + +* New commitEmailFormat option which can be set to "html" to generate + simple colorized diffs using HTML for the commit emails. + +* git-multimail can now be ran as a Gerrit ref-updated hook, or from + Atlassian BitBucket Server (formerly known as Atlassian Stash). + +* The From: field is now more customizeable. It can be set + independently for refchange emails and commit emails (see + fromCommit, fromRefChange). The special values pusher and author can + be used in these configuration variable. + +* A new command-line option, --version, was added. The version is also + available in the X-Git-Multimail-Version header of sent emails. + +* Set X-Git-NotificationType header to differentiate the various types + of notifications. Current values are: diff, ref_changed_plus_diff, + ref_changed. + +* Preliminary support for Python 3. The testsuite passes with Python 3, + but it has not received as much testing as the Python 2 version yet. + +* Several encoding-related fixes. UTF-8 characters work in more + situations (but non-ascii characters in email address are still not + supported). + +* The testsuite and its documentation has been greatly improved. + +Plus all the bugfixes from version 1.1.1. + +This version has been tested with Python 2.4 and 2.6 to 3.5, and Git +v1.7.10-406-gdc801e7, git-1.8.2.3 and 2.6.0. Git versions prior to +v1.7.10-406-gdc801e7 probably work, but cannot run the testsuite +properly. + +Release 1.1.1 (bugfix-only release) +=================================== + +* The SMTP mailer was not working with Python 2.4. + +Release 1.1.0 +============= + +* When a single commit is pushed, omit the reference changed email. + Set multimailhook.combineWhenSingleCommit to false to disable this + new feature. + +* In gitolite environments, the pusher's email address can be used as + the From address by creating a specially formatted comment block in + gitolite.conf (see multimailhook.from in README). + +* Support for SMTP authentication and SSL/TLS encryption was added, + see smtpUser, smtpPass, smtpEncryption in README. + +* A new option scanCommitForCc was added to allow git-multimail to + search the commit message for 'Cc: ...' lines, and add the + corresponding emails in Cc. + +* If $USER is not set, use the variable $USERNAME. This is needed on + Windows platform to recognize the pusher. + +* The emailPrefix variable can now be set to an empty string to remove + the prefix. + +* A short tutorial was added in doc/gitolite.rst to set up + git-multimail with gitolite. + +* The post-receive file was renamed to post-receive.example. It has + always been an example (the standard way to call git-multimail is to + call git_multimail.py), but it was unclear to many users. + +* A new refchangeShowGraph option was added to make it possible to + include both a graph and a log in the summary emails. The options + to control the graph formatting can be set via the new graphOpts + option. + +* New option --force-send was added to disable new commit detection + for update hook. One use-case is to run git_multimail.py after + running "git fetch" to send emails about commits that have just been + fetched (the detection of new commits was unreliable in this mode). + +* The testing infrastructure was considerably improved (continuous + integration with travis-ci, automatic check of PEP8 and RST syntax, + many improvements to the test scripts). + +This version has been tested with Python 2.4 to 2.7, and Git 1.7.1 to +2.4. + +Release 1.0.0 +============= + +* Fix encoding of non-ASCII email addresses in email headers. + +* Fix backwards-compatibility bugs for older Python 2.x versions. + +* Fix a backwards-compatibility bug for Git 1.7.1. + +* Add an option commitDiffOpts to customize logs for revisions. + +* Pass "-oi" to sendmail by default to prevent premature termination + on a line containing only ".". + +* Stagger email "Date:" values in an attempt to help mail clients + thread the emails in the right order. + +* If a mailing list setting is missing, just skip sending the + corresponding email (with a warning) instead of failing. + +* Add a X-Git-Host header that can be used for email filtering. + +* Allow the sender's fully-qualified domain name to be configured. + +* Minor documentation improvements. + +* Add this CHANGES file. + + +Release 0.9.0 +============= + +* Initial release. diff --git a/contrib/hooks/multimail/CONTRIBUTING.rst b/contrib/hooks/multimail/CONTRIBUTING.rst new file mode 100644 index 000000000000..de20a5428730 --- /dev/null +++ b/contrib/hooks/multimail/CONTRIBUTING.rst @@ -0,0 +1,60 @@ +Contributing +============ + +git-multimail is an open-source project, built by volunteers. We would +welcome your help! + +The current maintainers are `Matthieu Moy `__ and +`Michael Haggerty `__. + +Please note that although a copy of git-multimail is distributed in +the "contrib" section of the main Git project, development takes place +in a separate `git-multimail repository on GitHub`_. + +Whenever enough changes to git-multimail have accumulated, a new +code-drop of git-multimail will be submitted for inclusion in the Git +project. + +We use the GitHub issue tracker to keep track of bugs and feature +requests, and we use GitHub pull requests to exchange patches (though, +if you prefer, you can send patches via the Git mailing list with CC +to the maintainers). Please sign off your patches as per the `Git +project practice +`__. + +Please vote for issues you would like to be addressed in priority +(click "add your reaction" and then the "+1" thumbs-up button on the +GitHub issue). + +General discussion of git-multimail can take place on the main `Git +mailing list`_. + +Please CC emails regarding git-multimail to the maintainers so that we +don't overlook them. + +Help needed: testers/maintainer for specific environments/OS +------------------------------------------------------------ + +The current maintainer uses and tests git-multimail on Linux with the +Generic environment. More testers, or better contributors are needed +to test git-multimail on other real-life setups: + +* Mac OS X, Windows: git-multimail is currently not supported on these + platforms. But since we have no external dependencies and try to + write code as portable as possible, it is possible that + git-multimail already runs there and if not, it is likely that it + could be ported easily. + + Patches to improve support for Windows and OS X are welcome. + Ideally, there would be a sub-maintainer for each OS who would test + at least once before each release (around twice a year). + +* Gerrit, Stash, Gitolite environments: although the testsuite + contains tests for these environments, a tester/maintainer for each + environment would be welcome to test and report failure (or success) + on real-life environments periodically (here also, feedback before + each release would be highly appreciated). + + +.. _`git-multimail repository on GitHub`: https://github.com/git-multimail/git-multimail +.. _`Git mailing list`: git@vger.kernel.org diff --git a/contrib/hooks/multimail/README.Git b/contrib/hooks/multimail/README.Git new file mode 100644 index 000000000000..044444245d09 --- /dev/null +++ b/contrib/hooks/multimail/README.Git @@ -0,0 +1,15 @@ +This copy of git-multimail is distributed as part of the "contrib" +section of the Git project as a convenience to Git users. +git-multimail is developed as an independent project at the following +website: + + https://github.com/git-multimail/git-multimail + +The version in this directory was obtained from the upstream project +on January 07 2019 and consists of the "git-multimail" subdirectory from +revision + + 04e80e6c40be465cc62b6c246f0fcb8fd2cfd454 refs/tags/1.5.0 + +Please see the README file in this directory for information about how +to report bugs or contribute to git-multimail. diff --git a/contrib/hooks/multimail/README.migrate-from-post-receive-email b/contrib/hooks/multimail/README.migrate-from-post-receive-email new file mode 100644 index 000000000000..1e6a976699aa --- /dev/null +++ b/contrib/hooks/multimail/README.migrate-from-post-receive-email @@ -0,0 +1,145 @@ +git-multimail is close to, but not exactly, a plug-in replacement for +the old Git project script contrib/hooks/post-receive-email. This +document describes the differences and explains how to configure +git-multimail to get behavior closest to that of post-receive-email. + +If you are in a hurry +===================== + +A script called migrate-mailhook-config is included with +git-multimail. If you run this script within a Git repository that is +configured to use post-receive-email, it will convert the +configuration settings into the approximate equivalent settings for +git-multimail. For more information, run + + migrate-mailhook-config --help + + +Configuration differences +========================= + +* The names of the config options for git-multimail are in namespace + "multimailhook.*" instead of "hooks.*". (Editorial comment: + post-receive-email should never have used such a generic top-level + namespace.) + +* In emails about new annotated tags, post-receive-email includes a + shortlog of all changes since the previous annotated tag. To get + this behavior with git-multimail, you need to set + multimailhook.announceshortlog to true: + + git config multimailhook.announceshortlog true + +* multimailhook.commitlist -- This is a new configuration variable. + Recipients listed here will receive a separate email for each new + commit. However, if this variable is *not* set, it defaults to the + value of multimailhook.mailinglist. Therefore, if you *don't* want + the members of multimailhook.mailinglist to receive one email per + commit, then set this value to the empty string: + + git config multimailhook.commitlist '' + +* multimailhook.emailprefix -- If this value is not set, then the + subjects of generated emails are prefixed with the short name of the + repository enclosed in square brackets; e.g., "[myrepo]". + post-receive-email defaults to prefix "[SCM]" if this option is not + set. So if you were using the old default and want to retain it + (for example, to avoid having to change your email filters), set + this variable explicitly to the old value: + + git config multimailhook.emailprefix "[SCM]" + +* The "multimailhook.showrev" configuration option is not supported. + Its main use is obsoleted by the one-email-per-commit feature of + git-multimail. + + +Other differences +================= + +This section describes other differences in the behavior of +git-multimail vs. post-receive-email. For full details, please refer +to the main README file: + +* One email per commit. For each reference change, the script first + outputs one email summarizing the reference change (including + one-line summaries of the new commits), then it outputs a separate + email for each new commit that was introduced, including patches. + These one-email-per-commit emails go to the addresses listed in + multimailhook.commitlist. post-receive-email sends only one email + for each *reference* that is changed, no matter how many commits + were added to the reference. + +* Better algorithm for detecting new commits. post-receive-email + processes one reference change at a time, which causes it to fail to + describe new commits that were included in multiple branches. For + example, if a single push adds the "*" commits in the diagram below, + then post-receive-email would never include the details of the two + commits that are common to "master" and "branch" in its + notifications. + + o---o---o---*---*---* <-- master + \ + *---* <-- branch + + git-multimail analyzes all reference modifications to determine + which commits were not present before the change, therefore avoiding + that error. + +* In reference change emails, git-multimail tells which commits have + been added to the reference vs. are entirely new to the repository, + and which commits that have been omitted from the reference + vs. entirely discarded from the repository. + +* The environment in which Git is running can be configured via an + "Environment" abstraction. + +* Built-in support for Gitolite-managed repositories. + +* Instead of using full SHA1 object names in emails, git-multimail + mostly uses abbreviated SHA1s, plus one-line log message summaries + where appropriate. + +* In the schematic diagrams that explain non-fast-forward commits, + git-multimail shows the names of the branches involved. + +* The emails generated by git-multimail include the name of the Git + repository that was modified; this is convenient for recipients who + are monitoring multiple repositories. + +* git-multimail allows the email "From" addresses to be configured. + +* The recipients lists (multimailhook.mailinglist, + multimailhook.refchangelist, multimailhook.announcelist, and + multimailhook.commitlist) can be comma-separated values and/or + multivalued settings in the config file; e.g., + + [multimailhook] + mailinglist = mr.brown@example.com, mr.black@example.com + announcelist = Him + announcelist = Jim + announcelist = pop@example.com + + This might make it easier to maintain short recipients lists without + requiring full-fledged mailing list software. + +* By default, git-multimail sets email "Reply-To" headers to reply to + the pusher (for reference updates) and to the author (for commit + notifications). By default, the pusher's email address is + constructed by appending "multimailhook.emaildomain" to the pusher's + username. + +* The generated emails contain a configurable footer. By default, it + lists the name of the administrator who should be contacted to + unsubscribe from notification emails. + +* New option multimailhook.emailmaxlinelength to limit the length of + lines in the main part of the email body. The default limit is 500 + characters. + +* New option multimailhook.emailstrictutf8 to ensure that the main + part of the email body is valid UTF-8. Invalid characters are + turned into the Unicode replacement character, U+FFFD. By default + this option is turned on. + +* Written in Python. Easier to add new features. diff --git a/contrib/hooks/multimail/README.rst b/contrib/hooks/multimail/README.rst new file mode 100644 index 000000000000..7c0fc4a6ef00 --- /dev/null +++ b/contrib/hooks/multimail/README.rst @@ -0,0 +1,774 @@ +git-multimail version 1.5.0 +=========================== + +.. image:: https://travis-ci.org/git-multimail/git-multimail.svg?branch=master + :target: https://travis-ci.org/git-multimail/git-multimail + +git-multimail is a tool for sending notification emails on pushes to a +Git repository. It includes a Python module called ``git_multimail.py``, +which can either be used as a hook script directly or can be imported +as a Python module into another script. + +git-multimail is derived from the Git project's old +contrib/hooks/post-receive-email, and is mostly compatible with that +script. See README.migrate-from-post-receive-email for details about +the differences and for how to migrate from post-receive-email to +git-multimail. + +git-multimail, like the rest of the Git project, is licensed under +GPLv2 (see the COPYING file for details). + +Please note: although, as a convenience, git-multimail may be +distributed along with the main Git project, development of +git-multimail takes place in its own, separate project. Please, read +``__ for more information. + + +By default, for each push received by the repository, git-multimail: + +1. Outputs one email summarizing each reference that was changed. + These "reference change" (called "refchange" below) emails describe + the nature of the change (e.g., was the reference created, deleted, + fast-forwarded, etc.) and include a one-line summary of each commit + that was added to the reference. + +2. Outputs one email for each new commit that was introduced by the + reference change. These "commit" emails include a list of the + files changed by the commit, followed by the diffs of files + modified by the commit. The commit emails are threaded to the + corresponding reference change email via "In-Reply-To". This style + (similar to the "git format-patch" style used on the Git mailing + list) makes it easy to scan through the emails, jump to patches + that need further attention, and write comments about specific + commits. Commits are handled in reverse topological order (i.e., + parents shown before children). For example:: + + [git] branch master updated + + [git] 01/08: doc: fix xref link from api docs to manual pages + + [git] 02/08: api-credentials.txt: show the big picture first + + [git] 03/08: api-credentials.txt: mention credential.helper explicitly + + [git] 04/08: api-credentials.txt: add "see also" section + + [git] 05/08: t3510 (cherry-pick-sequence): add missing '&&' + + [git] 06/08: Merge branch 'rr/maint-t3510-cascade-fix' + + [git] 07/08: Merge branch 'mm/api-credentials-doc' + + [git] 08/08: Git 1.7.11-rc2 + + By default, each commit appears in exactly one commit email, the + first time that it is pushed to the repository. If a commit is later + merged into another branch, then a one-line summary of the commit + is included in the reference change email (as usual), but no + additional commit email is generated. See + `multimailhook.refFilter(Inclusion|Exclusion|DoSend|DontSend)Regex` + below to configure which branches and tags are watched by the hook. + + By default, reference change emails have their "Reply-To" field set + to the person who pushed the change, and commit emails have their + "Reply-To" field set to the author of the commit. + +3. Output one "announce" mail for each new annotated tag, including + information about the tag and optionally a shortlog describing the + changes since the previous tag. Such emails might be useful if you + use annotated tags to mark releases of your project. + + +Requirements +------------ + +* Python 2.x, version 2.4 or later. No non-standard Python modules + are required. git-multimail has preliminary support for Python 3 + (but it has been better tested with Python 2). + +* The ``git`` command must be in your PATH. git-multimail is known to + work with Git versions back to 1.7.1. (Earlier versions have not + been tested; if you do so, please report your results.) + +* To send emails using the default configuration, a standard sendmail + program must be located at '/usr/sbin/sendmail' or + '/usr/lib/sendmail' and must be configured correctly to send emails. + If this is not the case, set multimailhook.sendmailCommand, or see + the multimailhook.mailer configuration variable below for how to + configure git-multimail to send emails via an SMTP server. + +* git-multimail is currently tested only on Linux. It may or may not + work on other platforms such as Windows and Mac OS. See + ``__ to improve the situation. + + +Invocation +---------- + +``git_multimail.py`` is designed to be used as a ``post-receive`` hook in a +Git repository (see githooks(5)). Link or copy it to +$GIT_DIR/hooks/post-receive within the repository for which email +notifications are desired. Usually it should be installed on the +central repository for a project, to which all commits are eventually +pushed. + +For use on pre-v1.5.1 Git servers, ``git_multimail.py`` can also work as +an ``update`` hook, taking its arguments on the command line. To use +this script in this manner, link or copy it to $GIT_DIR/hooks/update. +Please note that the script is not completely reliable in this mode +[1]_. + +Alternatively, ``git_multimail.py`` can be imported as a Python module +into your own Python post-receive script. This method is a bit more +work, but allows the behavior of the hook to be customized using +arbitrary Python code. For example, you can use a custom environment +(perhaps inheriting from GenericEnvironment or GitoliteEnvironment) to + +* change how the user who did the push is determined + +* read users' email addresses from an LDAP server or from a database + +* decide which users should be notified about which commits based on + the contents of the commits (e.g., for users who want to be notified + only about changes affecting particular files or subdirectories) + +Or you can change how emails are sent by writing your own Mailer +class. The ``post-receive`` script in this directory demonstrates how +to use ``git_multimail.py`` as a Python module. (If you make interesting +changes of this type, please consider sharing them with the +community.) + + +Troubleshooting/FAQ +------------------- + +Please read ``__ for frequently asked +questions and common issues with git-multimail. + + +Configuration +------------- + +By default, git-multimail mostly takes its configuration from the +following ``git config`` settings: + +multimailhook.environment + This describes the general environment of the repository. In most + cases, you do not need to specify a value for this variable: + `git-multimail` will autodetect which environment to use. + Currently supported values: + + generic + the username of the pusher is read from $USER or $USERNAME and + the repository name is derived from the repository's path. + + gitolite + Environment to use when ``git-multimail`` is ran as a gitolite_ + hook. + + The username of the pusher is read from $GL_USER, the repository + name is read from $GL_REPO, and the From: header value is + optionally read from gitolite.conf (see multimailhook.from). + + For more information about gitolite and git-multimail, read + ``__ + + stash + Environment to use when ``git-multimail`` is ran as an Atlassian + BitBucket Server (formerly known as Atlassian Stash) hook. + + **Warning:** this mode was provided by a third-party contributor + and never tested by the git-multimail maintainers. It is + provided as-is and may or may not work for you. + + This value is automatically assumed when the stash-specific + flags (``--stash-user`` and ``--stash-repo``) are specified on + the command line. When this environment is active, the username + and repo come from these two command line flags, which must be + specified. + + gerrit + Environment to use when ``git-multimail`` is ran as a + ``ref-updated`` Gerrit hook. + + This value is used when the gerrit-specific command line flags + (``--oldrev``, ``--newrev``, ``--refname``, ``--project``) for + gerrit's ref-updated hook are present. When this environment is + active, the username of the pusher is taken from the + ``--submitter`` argument if that command line option is passed, + otherwise 'Gerrit' is used. The repository name is taken from + the ``--project`` option on the command line, which must be passed. + + For more information about gerrit and git-multimail, read + ``__ + + If none of these environments is suitable for your setup, then you + can implement a Python class that inherits from Environment and + instantiate it via a script that looks like the example + post-receive script. + + The environment value can be specified on the command line using + the ``--environment`` option. If it is not specified on the + command line or by ``multimailhook.environment``, the value is + guessed as follows: + + * If stash-specific (respectively gerrit-specific) command flags + are present on the command-line, then ``stash`` (respectively + ``gerrit``) is used. + + * If the environment variables $GL_USER and $GL_REPO are set, then + ``gitolite`` is used. + + * If none of the above apply, then ``generic`` is used. + +multimailhook.repoName + A short name of this Git repository, to be used in various places + in the notification email text. The default is to use $GL_REPO + for gitolite repositories, or otherwise to derive this value from + the repository path name. + +multimailhook.mailingList + The list of email addresses to which notification emails should be + sent, as RFC 2822 email addresses separated by commas. This + configuration option can be multivalued. Leave it unset or set it + to the empty string to not send emails by default. The next few + settings can be used to configure specific address lists for + specific types of notification email. + +multimailhook.refchangeList + The list of email addresses to which summary emails about + reference changes should be sent, as RFC 2822 email addresses + separated by commas. This configuration option can be + multivalued. The default is the value in + multimailhook.mailingList. Set this value to "none" (or the empty + string) to prevent reference change emails from being sent even if + multimailhook.mailingList is set. + +multimailhook.announceList + The list of email addresses to which emails about new annotated + tags should be sent, as RFC 2822 email addresses separated by + commas. This configuration option can be multivalued. The + default is the value in multimailhook.refchangeList or + multimailhook.mailingList. Set this value to "none" (or the empty + string) to prevent annotated tag announcement emails from being sent + even if one of the other values is set. + +multimailhook.commitList + The list of email addresses to which emails about individual new + commits should be sent, as RFC 2822 email addresses separated by + commas. This configuration option can be multivalued. The + default is the value in multimailhook.mailingList. Set this value + to "none" (or the empty string) to prevent notification emails about + individual commits from being sent even if + multimailhook.mailingList is set. + +multimailhook.announceShortlog + If this option is set to true, then emails about changes to + annotated tags include a shortlog of changes since the previous + tag. This can be useful if the annotated tags represent releases; + then the shortlog will be a kind of rough summary of what has + happened since the last release. But if your tagging policy is + not so straightforward, then the shortlog might be confusing + rather than useful. Default is false. + +multimailhook.commitEmailFormat + The format of email messages for the individual commits, can be "text" or + "html". In the latter case, the emails will include diffs using colorized + HTML instead of plain text used by default. Note that this currently the + ref change emails are always sent in plain text. + + Note that when using "html", the formatting is done by parsing the + output of ``git log`` with ``-p``. When using + ``multimailhook.commitLogOpts`` to specify a ``--format`` for + ``git log``, one may get false positive (e.g. lines in the body of + the message starting with ``+++`` or ``---`` colored in red or + green). + + By default, all the message is HTML-escaped. See + ``multimailhook.htmlInIntro`` to change this behavior. + +multimailhook.commitBrowseURL + Used to generate a link to an online repository browser in commit + emails. This variable must be a string. Format directives like + ``%()s`` will be expanded the same way as template + strings. In particular, ``%(id)s`` will be replaced by the full + Git commit identifier (40-chars hexadecimal). + + If the string does not contain any format directive, then + ``%(id)s`` will be automatically added to the string. If you don't + want ``%(id)s`` to be automatically added, use the empty format + directive ``%()s`` anywhere in the string. + + For example, a suitable value for the git-multimail project itself + would be + ``https://github.com/git-multimail/git-multimail/commit/%(id)s``. + +multimailhook.htmlInIntro, multimailhook.htmlInFooter + When generating an HTML message, git-multimail escapes any HTML + sequence by default. This means that if a template contains HTML + like ``link``, the reader will see the HTML + source code and not a proper link. + + Set ``multimailhook.htmlInIntro`` to true to allow writing HTML + formatting in introduction templates. Similarly, set + ``multimailhook.htmlInFooter`` for HTML in the footer. + + Variables expanded in the template are still escaped. For example, + if a repository's path contains a ``<``, it will be rendered as + such in the message. + + Read ``__ for more details and + examples. + +multimailhook.refchangeShowGraph + If this option is set to true, then summary emails about reference + changes will additionally include: + + * a graph of the added commits (if any) + + * a graph of the discarded commits (if any) + + The log is generated by running ``git log --graph`` with the options + specified in graphOpts. The default is false. + +multimailhook.refchangeShowLog + If this option is set to true, then summary emails about reference + changes will include a detailed log of the added commits in + addition to the one line summary. The log is generated by running + ``git log`` with the options specified in multimailhook.logOpts. + Default is false. + +multimailhook.mailer + This option changes the way emails are sent. Accepted values are: + + * **sendmail (the default)**: use the command ``/usr/sbin/sendmail`` or + ``/usr/lib/sendmail`` (or sendmailCommand, if configured). This + mode can be further customized via the following options: + + multimailhook.sendmailCommand + The command used by mailer ``sendmail`` to send emails. Shell + quoting is allowed in the value of this setting, but remember that + Git requires double-quotes to be escaped; e.g.:: + + git config multimailhook.sendmailcommand '/usr/sbin/sendmail -oi -t -F \"Git Repo\"' + + Default is '/usr/sbin/sendmail -oi -t' or + '/usr/lib/sendmail -oi -t' (depending on which file is + present and executable). + + multimailhook.envelopeSender + If set then pass this value to sendmail via the -f option to set + the envelope sender address. + + * **smtp**: use Python's smtplib. This is useful when the sendmail + command is not available on the system. This mode can be + further customized via the following options: + + multimailhook.smtpServer + The name of the SMTP server to connect to. The value can + also include a colon and a port number; e.g., + ``mail.example.com:25``. Default is 'localhost' using port 25. + + multimailhook.smtpUser, multimailhook.smtpPass + Server username and password. Required if smtpEncryption is 'ssl'. + Note that the username and password currently need to be + set cleartext in the configuration file, which is not + recommended. If you need to use this option, be sure your + configuration file is read-only. + + multimailhook.envelopeSender + The sender address to be passed to the SMTP server. If + unset, then the value of multimailhook.from is used. + + multimailhook.smtpServerTimeout + Timeout in seconds. Default is 10. + + multimailhook.smtpEncryption + Set the security type. Allowed values: ``none``, ``ssl``, ``tls`` (starttls). + Default is ``none``. + + multimailhook.smtpCACerts + Set the path to a list of trusted CA certificate to verify the + server certificate, only supported when ``smtpEncryption`` is + ``tls``. If unset or empty, the server certificate is not + verified. If it targets a file containing a list of trusted CA + certificates (PEM format) these CAs will be used to verify the + server certificate. For debian, you can set + ``/etc/ssl/certs/ca-certificates.crt`` for using the system + trusted CAs. For self-signed server, you can add your server + certificate to the system store:: + + cd /usr/local/share/ca-certificates/ + openssl s_client -starttls smtp \ + -connect mail.example.net:587 -showcerts \ + /dev/null \ + | openssl x509 -outform PEM >mail.example.net.crt + update-ca-certificates + + and used the updated ``/etc/ssl/certs/ca-certificates.crt``. Or + directly use your ``/path/to/mail.example.net.crt``. Default is + unset. + + multimailhook.smtpServerDebugLevel + Integer number. Set to greater than 0 to activate debugging. + +multimailhook.from, multimailhook.fromCommit, multimailhook.fromRefchange + If set, use this value in the From: field of generated emails. + ``fromCommit`` is used for commit emails, ``fromRefchange`` is + used for refchange emails, and ``from`` is used as fall-back in + all cases. + + The value for these variables can be either: + + - An email address, which will be used directly. + + - The value ``pusher``, in which case the pusher's address (if + available) will be used. + + - The value ``author`` (meaningful only for ``fromCommit``), in which + case the commit author's address will be used. + + If config values are unset, the value of the From: header is + determined as follows: + + 1. (gitolite environment only) + 1.a) If ``multimailhook.MailaddressMap`` is set, and is a path + to an existing file (if relative, it is considered relative to + the place where ``gitolite.conf`` is located), then this file + should contain lines like:: + + username Firstname Lastname + + git-multimail will then look for a line where ``$GL_USER`` + matches the ``username`` part, and use the rest of the line for + the ``From:`` header. + + 1.b) Parse gitolite.conf, looking for a block of comments that + looks like this:: + + # BEGIN USER EMAILS + # username Firstname Lastname + # END USER EMAILS + + If that block exists, and there is a line between the BEGIN + USER EMAILS and END USER EMAILS lines where the first field + matches the gitolite username ($GL_USER), use the rest of the + line for the From: header. + + 2. If the user.email configuration setting is set, use its value + (and the value of user.name, if set). + + 3. Use the value of multimailhook.envelopeSender. + +multimailhook.MailaddressMap + (gitolite environment only) + File to look for a ``From:`` address based on the user doing the + push. Defaults to unset. See ``multimailhook.from`` for details. + +multimailhook.administrator + The name and/or email address of the administrator of the Git + repository; used in FOOTER_TEMPLATE. Default is + multimailhook.envelopesender if it is set; otherwise a generic + string is used. + +multimailhook.emailPrefix + All emails have this string prepended to their subjects, to aid + email filtering (though filtering based on the X-Git-* email + headers is probably more robust). Default is the short name of + the repository in square brackets; e.g., ``[myrepo]``. Set this + value to the empty string to suppress the email prefix. You may + use the placeholder ``%(repo_shortname)s`` for the short name of + the repository. + +multimailhook.emailMaxLines + The maximum number of lines that should be included in the body of + a generated email. If not specified, there is no limit. Lines + beyond the limit are suppressed and counted, and a final line is + added indicating the number of suppressed lines. + +multimailhook.emailMaxLineLength + The maximum length of a line in the email body. Lines longer than + this limit are truncated to this length with a trailing ``[...]`` + added to indicate the missing text. The default is 500, because + (a) diffs with longer lines are probably from binary files, for + which a diff is useless, and (b) even if a text file has such long + lines, the diffs are probably unreadable anyway. To disable line + truncation, set this option to 0. + +multimailhook.subjectMaxLength + The maximum length of the subject line (i.e. the ``oneline`` field + in templates, not including the prefix). Lines longer than this + limit are truncated to this length with a trailing ``[...]`` added + to indicate the missing text. This option The default is to use + ``multimailhook.emailMaxLineLength``. This option avoids sending + emails with overly long subject lines, but should not be needed if + the commit messages follow the Git convention (one short subject + line, then a blank line, then the message body). To disable line + truncation, set this option to 0. + +multimailhook.maxCommitEmails + The maximum number of commit emails to send for a given change. + When the number of patches is larger that this value, only the + summary refchange email is sent. This can avoid accidental + mailbombing, for example on an initial push. To disable commit + emails limit, set this option to 0. The default is 500. + +multimailhook.excludeMergeRevisions + When sending out revision emails, do not consider merge commits (the + functional equivalent of `rev-list --no-merges`). + The default is `false` (send merge commit emails). + +multimailhook.emailStrictUTF8 + If this boolean option is set to `true`, then the main part of the + email body is forced to be valid UTF-8. Any characters that are + not valid UTF-8 are converted to the Unicode replacement + character, U+FFFD. The default is `true`. + + This option is ineffective with Python 3, where non-UTF-8 + characters are unconditionally replaced. + +multimailhook.diffOpts + Options passed to ``git diff-tree`` when generating the summary + information for ReferenceChange emails. Default is ``--stat + --summary --find-copies-harder``. Add -p to those options to + include a unified diff of changes in addition to the usual summary + output. Shell quoting is allowed; see ``multimailhook.logOpts`` for + details. + +multimailhook.graphOpts + Options passed to ``git log --graph`` when generating graphs for the + reference change summary emails (used only if refchangeShowGraph + is true). The default is '--oneline --decorate'. + + Shell quoting is allowed; see logOpts for details. + +multimailhook.logOpts + Options passed to ``git log`` to generate additional info for + reference change emails (used only if refchangeShowLog is set). + For example, adding -p will show each commit's complete diff. The + default is empty. + + Shell quoting is allowed; for example, a log format that contains + spaces can be specified using something like:: + + git config multimailhook.logopts '--pretty=format:"%h %aN <%aE>%n%s%n%n%b%n"' + + If you want to set this by editing your configuration file + directly, remember that Git requires double-quotes to be escaped + (see git-config(1) for more information):: + + [multimailhook] + logopts = --pretty=format:\"%h %aN <%aE>%n%s%n%n%b%n\" + +multimailhook.commitLogOpts + Options passed to ``git log`` to generate additional info for + revision change emails. For example, adding --ignore-all-spaces + will suppress whitespace changes. The default options are ``-C + --stat -p --cc``. Shell quoting is allowed; see + multimailhook.logOpts for details. + +multimailhook.dateSubstitute + String to use as a substitute for ``Date:`` in the output of ``git + log`` while formatting commit messages. This is useful to avoid + emitting a line that can be interpreted by mailers as the start of + a cited message (Zimbra webmail in particular). Defaults to + ``CommitDate:``. Set to an empty string or ``none`` to deactivate + the behavior. + +multimailhook.emailDomain + Domain name appended to the username of the person doing the push + to convert it into an email address + (via ``"%s@%s" % (username, emaildomain)``). More complicated + schemes can be implemented by overriding Environment and + overriding its get_pusher_email() method. + +multimailhook.replyTo, multimailhook.replyToCommit, multimailhook.replyToRefchange + Addresses to use in the Reply-To: field for commit emails + (replyToCommit) and refchange emails (replyToRefchange). + multimailhook.replyTo is used as default when replyToCommit or + replyToRefchange is not set. The shortcuts ``pusher`` and + ``author`` are allowed with the same semantics as for + ``multimailhook.from``. In addition, the value ``none`` can be + used to omit the ``Reply-To:`` field. + + The default is ``pusher`` for refchange emails, and ``author`` for + commit emails. + +multimailhook.quiet + Do not output the list of email recipients from the hook + +multimailhook.stdout + For debugging, send emails to stdout rather than to the + mailer. Equivalent to the --stdout command line option + +multimailhook.scanCommitForCc + If this option is set to true, than recipients from lines in commit body + that starts with ``CC:`` will be added to CC list. + Default: false + +multimailhook.combineWhenSingleCommit + If this option is set to true and a single new commit is pushed to + a branch, combine the summary and commit email messages into a + single email. + Default: true + +multimailhook.refFilterInclusionRegex, multimailhook.refFilterExclusionRegex, multimailhook.refFilterDoSendRegex, multimailhook.refFilterDontSendRegex + **Warning:** these options are experimental. They should work, but + the user-interface is not stable yet (in particular, the option + names may change). If you want to participate in stabilizing the + feature, please contact the maintainers and/or send pull-requests. + If you are happy with the current shape of the feature, please + report it too. + + Regular expressions that can be used to limit refs for which email + updates will be sent. It is an error to specify both an inclusion + and an exclusion regex. If a ``refFilterInclusionRegex`` is + specified, emails will only be sent for refs which match this + regex. If a ``refFilterExclusionRegex`` regex is specified, + emails will be sent for all refs except those that match this + regex (or that match a predefined regex specific to the + environment, such as "^refs/notes" for most environments and + "^refs/notes|^refs/changes" for the gerrit environment). + + The expressions are matched against the complete refname, and is + considered to match if any substring matches. For example, to + filter-out all tags, set ``refFilterExclusionRegex`` to + ``^refs/tags/`` (note the leading ``^`` but no trailing ``$``). If + you set ``refFilterExclusionRegex`` to ``master``, then any ref + containing ``master`` will be excluded (the ``master`` branch, but + also ``refs/tags/master`` or ``refs/heads/foo-master-bar``). + + ``refFilterDoSendRegex`` and ``refFilterDontSendRegex`` are + analogous to ``refFilterInclusionRegex`` and + ``refFilterExclusionRegex`` with one difference: with + ``refFilterDoSendRegex`` and ``refFilterDontSendRegex``, commits + introduced by one excluded ref will not be considered as new when + they reach an included ref. Typically, if you add a branch ``foo`` + to ``refFilterDontSendRegex``, push commits to this branch, and + later merge branch ``foo`` into ``master``, then the notification + email for ``master`` will contain a commit email only for the + merge commit. If you include ``foo`` in + ``refFilterExclusionRegex``, then at the time of merge, you will + receive one commit email per commit in the branch. + + These variables can be multi-valued, like:: + + [multimailhook] + refFilterExclusionRegex = ^refs/tags/ + refFilterExclusionRegex = ^refs/heads/master$ + + You can also provide a whitespace-separated list like:: + + [multimailhook] + refFilterExclusionRegex = ^refs/tags/ ^refs/heads/master$ + + Both examples exclude tags and the master branch, and are + equivalent to:: + + [multimailhook] + refFilterExclusionRegex = ^refs/tags/|^refs/heads/master$ + + ``refFilterInclusionRegex`` and ``refFilterExclusionRegex`` are + strictly stronger than ``refFilterDoSendRegex`` and + ``refFilterDontSendRegex``. In other words, adding a ref to a + DoSend/DontSend regex has no effect if it is already excluded by a + Exclusion/Inclusion regex. + +multimailhook.logFile, multimailhook.errorLogFile, multimailhook.debugLogFile + + When set, these variable designate path to files where + git-multimail will log some messages. Normal messages and error + messages are sent to ``logFile``, and error messages are also sent + to ``errorLogFile``. Debug messages and all other messages are + sent to ``debugLogFile``. The recommended way is to set only one + of these variables, but it is also possible to set several of them + (part of the information is then duplicated in several log files, + for example errors are duplicated to all log files). + + Relative path are relative to the Git repository where the push is + done. + +multimailhook.verbose + + Verbosity level of git-multimail on its standard output. By + default, show only error and info messages. If set to true, show + also debug messages. + +Email filtering aids +-------------------- + +All emails include extra headers to enable fine tuned filtering and +give information for debugging. All emails include the headers +``X-Git-Host``, ``X-Git-Repo``, ``X-Git-Refname``, and ``X-Git-Reftype``. +ReferenceChange emails also include headers ``X-Git-Oldrev`` and ``X-Git-Newrev``; +Revision emails also include header ``X-Git-Rev``. + + +Customizing email contents +-------------------------- + +git-multimail mostly generates emails by expanding templates. The +templates can be customized. To avoid the need to edit +``git_multimail.py`` directly, the preferred way to change the templates +is to write a separate Python script that imports ``git_multimail.py`` as +a module, then replaces the templates in place. See the provided +post-receive script for an example of how this is done. + + +Customizing git-multimail for your environment +---------------------------------------------- + +git-multimail is mostly customized via an "environment" that describes +the local environment in which Git is running. Two types of +environment are built in: + +GenericEnvironment + a stand-alone Git repository. + +GitoliteEnvironment + a Git repository that is managed by gitolite_. For such + repositories, the identity of the pusher is read from + environment variable $GL_USER, the name of the repository is read + from $GL_REPO (if it is not overridden by multimailhook.reponame), + and the From: header value is optionally read from gitolite.conf + (see multimailhook.from). + +By default, git-multimail assumes GitoliteEnvironment if $GL_USER and +$GL_REPO are set, and otherwise assumes GenericEnvironment. +Alternatively, you can choose one of these two environments explicitly +by setting a ``multimailhook.environment`` config setting (which can +have the value `generic` or `gitolite`) or by passing an --environment +option to the script. + +If you need to customize the script in ways that are not supported by +the existing environments, you can define your own environment class +class using arbitrary Python code. To do so, you need to import +``git_multimail.py`` as a Python module, as demonstrated by the example +post-receive script. Then implement your environment class; it should +usually inherit from one of the existing Environment classes and +possibly one or more of the EnvironmentMixin classes. Then set the +``environment`` variable to an instance of your own environment class +and pass it to ``run_as_post_receive_hook()``. + +The standard environment classes, GenericEnvironment and +GitoliteEnvironment, are in fact themselves put together out of a +number of mixin classes, each of which handles one aspect of the +customization. For the finest control over your configuration, you +can specify exactly which mixin classes your own environment class +should inherit from, and override individual methods (or even add your +own mixin classes) to implement entirely new behaviors. If you +implement any mixins that might be useful to other people, please +consider sharing them with the community! + + +Getting involved +---------------- + +Please, read ``__ for instructions on how to +contribute to git-multimail. + + +Footnotes +--------- + +.. [1] Because of the way information is passed to update hooks, the + script's method of determining whether a commit has already + been seen does not work when it is used as an ``update`` script. + In particular, no notification email will be generated for a + new commit that is added to multiple references in the same + push. A workaround is to use --force-send to force sending the + emails. + +.. _gitolite: https://github.com/sitaramc/gitolite diff --git a/contrib/hooks/multimail/doc/customizing-emails.rst b/contrib/hooks/multimail/doc/customizing-emails.rst new file mode 100644 index 000000000000..3f5b67f768db --- /dev/null +++ b/contrib/hooks/multimail/doc/customizing-emails.rst @@ -0,0 +1,56 @@ +Customizing the content and formatting of emails +================================================ + +Overloading template strings +---------------------------- + +The content of emails is generated based on template strings defined +in ``git_multimail.py``. You can customize these template strings +without changing the script itself, by defining a Python wrapper +around it. The python wrapper should ``import git_multimail`` and then +override the ``git_multimail.*`` strings like this:: + + import sys # needed for sys.argv + + # Import and customize git_multimail: + import git_multimail + git_multimail.REVISION_INTRO_TEMPLATE = """...""" + git_multimail.COMBINED_INTRO_TEMPLATE = git_multimail.REVISION_INTRO_TEMPLATE + + # start git_multimail itself: + git_multimail.main(sys.argv[1:]) + +The template strings can use any value already used in the existing +templates (read the source code). + +Using HTML in template strings +------------------------------ + +If ``multimailhook.commitEmailFormat`` is set to HTML, then +git-multimail will generate HTML emails for commit notifications. The +log and diff will be formatted automatically by git-multimail. By +default, any HTML special character in the templates will be escaped. + +To use HTML formatting in the introduction of the email, set +``multimailhook.htmlInIntro`` to ``true``. Then, the template can +contain any HTML tags, that will be sent as-is in the email. For +example, to add some formatting and a link to the online commit, use +a format like:: + + git_multimail.REVISION_INTRO_TEMPLATE = """\ + This is an automated email from the git hooks/post-receive script.

+ + %(pusher)s pushed a commit to %(refname_type)s %(short_refname)s + in repository %(repo_shortname)s.
+ + View on GitHub. + """ + +Note that the values expanded from ``%(variable)s`` in the format +strings will still be escaped. + +For a less flexible but easier to set up way to add a link to commit +emails, see ``multimailhook.commitBrowseURL``. + +Similarly, one can set ``multimailhook.htmlInFooter`` and override any +of the ``*_FOOTER*`` template strings. diff --git a/contrib/hooks/multimail/doc/gerrit.rst b/contrib/hooks/multimail/doc/gerrit.rst new file mode 100644 index 000000000000..8011d05dec03 --- /dev/null +++ b/contrib/hooks/multimail/doc/gerrit.rst @@ -0,0 +1,56 @@ +Setting up git-multimail on Gerrit +================================== + +Gerrit has its own email-sending system, but you may prefer using +``git-multimail`` instead. It supports Gerrit natively as a Gerrit +``ref-updated`` hook (Warning: `Gerrit hooks +`__ +are distinct from Git hooks). Setting up ``git-multimail`` on a Gerrit +installation can be done following the instructions below. + +The explanations show an easy way to set up ``git-multimail``, +but leave ``git-multimail`` installed and unconfigured for a while. If +you run Gerrit on a production server, it is advised that you +execute the step "Set up the hook" last to avoid confusing your users +in the meantime. + +Set up the hook +--------------- + +Create a directory ``$site_path/hooks/`` if it does not exist (if you +don't know what ``$site_path`` is, run ``gerrit.sh status`` and look +for a ``GERRIT_SITE`` line). Either copy ``git_multimail.py`` to +``$site_path/hooks/ref-updated`` or create a wrapper script like +this:: + + #! /bin/sh + exec /path/to/git_multimail.py "$@" + +In both cases, make sure the file is named exactly +``$site_path/hooks/ref-updated`` and is executable. + +(Alternatively, you may configure the ``[hooks]`` section of +gerrit.config) + +Configuration +------------- + +Log on the gerrit server and edit ``$site_path/git/$project/config`` +to configure ``git-multimail``. + +Troubleshooting +--------------- + +Warning: this will disable ``git-multimail`` during the debug, and +could confuse your users. Don't run on a production server. + +To debug configuration issues with ``git-multimail``, you can add the +``--stdout`` option when calling ``git_multimail.py`` like this:: + + #!/bin/sh + exec /path/to/git-multimail/git-multimail/git_multimail.py \ + --stdout "$@" >> /tmp/log.txt + +and try pushing from a test repository. You should see the source of +the email that would have been sent in the output of ``git push`` in +the file ``/tmp/log.txt``. diff --git a/contrib/hooks/multimail/doc/gitolite.rst b/contrib/hooks/multimail/doc/gitolite.rst new file mode 100644 index 000000000000..505483310552 --- /dev/null +++ b/contrib/hooks/multimail/doc/gitolite.rst @@ -0,0 +1,118 @@ +Setting up git-multimail on gitolite +==================================== + +``git-multimail`` supports gitolite 3 natively. +The explanations below show an easy way to set up ``git-multimail``, +but leave ``git-multimail`` installed and unconfigured for a while. If +you run gitolite on a production server, it is advised that you +execute the step "Set up the hook" last to avoid confusing your users +in the meantime. + +Set up the hook +--------------- + +Log in as your gitolite user. + +Create a file ``.gitolite/hooks/common/post-receive`` on your gitolite +account containing (adapt the path, obviously):: + + #!/bin/sh + exec /path/to/git-multimail/git-multimail/git_multimail.py "$@" + +Make sure it's executable (``chmod +x``). Record the hook in +gitolite:: + + gitolite setup + +Configuration +------------- + +First, you have to allow the admin to set Git configuration variables. + +As gitolite user, edit the line containing ``GIT_CONFIG_KEYS`` in file +``.gitolite.rc``, to make it look like:: + + GIT_CONFIG_KEYS => 'multimailhook\..*', + +You can now log out and return to your normal user. + +In the ``gitolite-admin`` clone, edit the file ``conf/gitolite.conf`` +and add:: + + repo @all + # Not strictly needed as git_multimail.py will chose gitolite if + # $GL_USER is set. + config multimailhook.environment = gitolite + config multimailhook.mailingList = # Where emails should be sent + config multimailhook.from = # From address to use + +Note that by default, gitolite forbids ``<`` and ``>`` in variable +values (for security/paranoia reasons, see +`compensating for UNSAFE_PATT +`__ +in gitolite's documentation for explanations and a way to disable +this). As a consequence, you will not be able to use ``First Last +`` as recipient email, but specifying +``First.Last@example.com`` alone works. + +Obviously, you can customize all parameters on a per-repository basis by +adding these ``config multimailhook.*`` lines in the section +corresponding to a repository or set of repositories. + +To activate ``git-multimail`` on a per-repository basis, do not set +``multimailhook.mailingList`` in the ``@all`` section and set it only +for repositories for which you want ``git-multimail``. + +Alternatively, you can set up the ``From:`` field on a per-user basis +by adding a ``BEGIN USER EMAILS``/``END USER EMAILS`` section (see +``../README``). + +Specificities of Gitolite for Configuration +------------------------------------------- + +Empty configuration variables +............................. + +With gitolite, the syntax ``config multimailhook.commitList = ""`` +unsets the variable instead of setting it to an empty string (see +`here +`__). +As a result, there is no way to set a variable to the empty string. +In all most places where an empty value is required, git-multimail +now allows to specify special ``"none"`` value (case-sensitive) to +mean the same. + +Alternatively, one can use ``" "`` (a single space) instead of ``""``. +In most cases (in particular ``multimailhook.*List`` variables), this +will be equivalent to an empty string. + +If you have a use-case where ``"none"`` is not an acceptable value and +you need ``" "`` or ``""`` instead, please report it as a bug to +git-multimail. + +Allowing Regular Expressions in Configuration +............................................. + +gitolite has a mechanism to prevent unsafe configuration variable +values, which prevent characters like ``|`` commonly used in regular +expressions. If you do not need the safety feature of gitolite and +need to use regular expressions in your configuration (e.g. for +``multimailhook.refFilter*`` variables), set +`UNSAFE_PATT +`__ to a +less restrictive value. + +Troubleshooting +--------------- + +Warning: this will disable ``git-multimail`` during the debug, and +could confuse your users. Don't run on a production server. + +To debug configuration issues with ``git-multimail``, you can add the +``--stdout`` option when calling ``git_multimail.py`` like this:: + + #!/bin/sh + exec /path/to/git-multimail/git-multimail/git_multimail.py --stdout "$@" + +and try pushing from a test repository. You should see the source of +the email that would have been sent in the output of ``git push``. diff --git a/contrib/hooks/multimail/doc/troubleshooting.rst b/contrib/hooks/multimail/doc/troubleshooting.rst new file mode 100644 index 000000000000..651b509ee66c --- /dev/null +++ b/contrib/hooks/multimail/doc/troubleshooting.rst @@ -0,0 +1,78 @@ +Troubleshooting issues with git-multimail: a FAQ +================================================ + +How to check that git-multimail is properly set up? +--------------------------------------------------- + +Since version 1.4.0, git-multimail allows a simple self-checking of +its configuration: run it with the environment variable +``GIT_MULTIMAIL_CHECK_SETUP`` set to a non-empty string. You should +get something like this:: + + $ GIT_MULTIMAIL_CHECK_SETUP=true /home/moy/dev/git-multimail/git-multimail/git_multimail.py + Environment values: + administrator : 'the administrator of this repository' + charset : 'utf-8' + emailprefix : '[git-multimail] ' + fqdn : 'anie' + projectdesc : 'UNNAMED PROJECT' + pusher : 'moy' + repo_path : '/home/moy/dev/git-multimail' + repo_shortname : 'git-multimail' + + Now, checking that git-multimail's standard input is properly set ... + Please type some text and then press Return + foo + You have just entered: + foo + git-multimail seems properly set up. + +If you forgot to set an important variable, you may get instead:: + + $ GIT_MULTIMAIL_CHECK_SETUP=true /home/moy/dev/git-multimail/git-multimail/git_multimail.py + No email recipients configured! + +Do not set ``$GIT_MULTIMAIL_CHECK_SETUP`` other than for testing your +configuration: it would disable the hook completely. + +Git is not using the right address in the From/To/Reply-To field +---------------------------------------------------------------- + +First, make sure that git-multimail actually uses what you think it is +using. A lot happens to your email (especially when posting to a +mailing-list) between the time `git_multimail.py` sends it and the +time it reaches your inbox. + +A simple test (to do on a test repository, do not use in production as +it would disable email sending): change your post-receive hook to call +`git_multimail.py` with the `--stdout` option, and try to push to the +repository. You should see something like:: + + Counting objects: 3, done. + Writing objects: 100% (3/3), 263 bytes | 0 bytes/s, done. + Total 3 (delta 0), reused 0 (delta 0) + remote: Sending notification emails to: foo.bar@example.com + remote: =========================================================================== + remote: Date: Mon, 25 Apr 2016 18:39:59 +0200 + remote: To: foo.bar@example.com + remote: Subject: [git] branch master updated: foo + remote: MIME-Version: 1.0 + remote: Content-Type: text/plain; charset=utf-8 + remote: Content-Transfer-Encoding: 8bit + remote: Message-ID: <20160425163959.2311.20498@anie> + remote: From: Auth Or + remote: Reply-To: Auth Or + remote: X-Git-Host: example + ... + remote: -- + remote: To stop receiving notification emails like this one, please contact + remote: the administrator of this repository. + remote: =========================================================================== + To /path/to/repo + 6278f04..e173f20 master -> master + +Note: this does not include the sender (Return-Path: header), as it is +not part of the message content but passed to the mailer. Some mailer +show the ``Sender:`` field instead of the ``From:`` field (for +example, Zimbra Webmail shows ``From: on behalf of +``). diff --git a/contrib/hooks/multimail/git_multimail.py b/contrib/hooks/multimail/git_multimail.py new file mode 100755 index 000000000000..8823399e7522 --- /dev/null +++ b/contrib/hooks/multimail/git_multimail.py @@ -0,0 +1,4346 @@ +#! /usr/bin/env python + +__version__ = '1.5.0' + +# Copyright (c) 2015-2016 Matthieu Moy and others +# Copyright (c) 2012-2014 Michael Haggerty and others +# Derived from contrib/hooks/post-receive-email, which is +# Copyright (c) 2007 Andy Parkins +# and also includes contributions by other authors. +# +# This file is part of git-multimail. +# +# git-multimail is free software: you can redistribute it and/or +# modify it under the terms of the GNU General Public License version +# 2 as published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see +# . + +"""Generate notification emails for pushes to a git repository. + +This hook sends emails describing changes introduced by pushes to a +git repository. For each reference that was changed, it emits one +ReferenceChange email summarizing how the reference was changed, +followed by one Revision email for each new commit that was introduced +by the reference change. + +Each commit is announced in exactly one Revision email. If the same +commit is merged into another branch in the same or a later push, then +the ReferenceChange email will list the commit's SHA1 and its one-line +summary, but no new Revision email will be generated. + +This script is designed to be used as a "post-receive" hook in a git +repository (see githooks(5)). It can also be used as an "update" +script, but this usage is not completely reliable and is deprecated. + +To help with debugging, this script accepts a --stdout option, which +causes the emails to be written to standard output rather than sent +using sendmail. + +See the accompanying README file for the complete documentation. + +""" + +import sys +import os +import re +import bisect +import socket +import subprocess +import shlex +import optparse +import logging +import smtplib +try: + import ssl +except ImportError: + # Python < 2.6 do not have ssl, but that's OK if we don't use it. + pass +import time + +import uuid +import base64 + +PYTHON3 = sys.version_info >= (3, 0) + +if sys.version_info <= (2, 5): + def all(iterable): + for element in iterable: + if not element: + return False + return True + + +def is_ascii(s): + return all(ord(c) < 128 and ord(c) > 0 for c in s) + + +if PYTHON3: + def is_string(s): + return isinstance(s, str) + + def str_to_bytes(s): + return s.encode(ENCODING) + + def bytes_to_str(s, errors='strict'): + return s.decode(ENCODING, errors) + + unicode = str + + def write_str(f, msg): + # Try outputing with the default encoding. If it fails, + # try UTF-8. + try: + f.buffer.write(msg.encode(sys.getdefaultencoding())) + except UnicodeEncodeError: + f.buffer.write(msg.encode(ENCODING)) + + def read_line(f): + # Try reading with the default encoding. If it fails, + # try UTF-8. + out = f.buffer.readline() + try: + return out.decode(sys.getdefaultencoding()) + except UnicodeEncodeError: + return out.decode(ENCODING) + + import html + + def html_escape(s): + return html.escape(s) + +else: + def is_string(s): + try: + return isinstance(s, basestring) + except NameError: # Silence Pyflakes warning + raise + + def str_to_bytes(s): + return s + + def bytes_to_str(s, errors='strict'): + return s + + def write_str(f, msg): + f.write(msg) + + def read_line(f): + return f.readline() + + def next(it): + return it.next() + + import cgi + + def html_escape(s): + return cgi.escape(s, True) + +try: + from email.charset import Charset + from email.utils import make_msgid + from email.utils import getaddresses + from email.utils import formataddr + from email.utils import formatdate + from email.header import Header +except ImportError: + # Prior to Python 2.5, the email module used different names: + from email.Charset import Charset + from email.Utils import make_msgid + from email.Utils import getaddresses + from email.Utils import formataddr + from email.Utils import formatdate + from email.Header import Header + + +DEBUG = False + +ZEROS = '0' * 40 +LOGBEGIN = '- Log -----------------------------------------------------------------\n' +LOGEND = '-----------------------------------------------------------------------\n' + +ADDR_HEADERS = set(['from', 'to', 'cc', 'bcc', 'reply-to', 'sender']) + +# It is assumed in many places that the encoding is uniformly UTF-8, +# so changing these constants is unsupported. But define them here +# anyway, to make it easier to find (at least most of) the places +# where the encoding is important. +(ENCODING, CHARSET) = ('UTF-8', 'utf-8') + + +REF_CREATED_SUBJECT_TEMPLATE = ( + '%(emailprefix)s%(refname_type)s %(short_refname)s created' + ' (now %(newrev_short)s)' + ) +REF_UPDATED_SUBJECT_TEMPLATE = ( + '%(emailprefix)s%(refname_type)s %(short_refname)s updated' + ' (%(oldrev_short)s -> %(newrev_short)s)' + ) +REF_DELETED_SUBJECT_TEMPLATE = ( + '%(emailprefix)s%(refname_type)s %(short_refname)s deleted' + ' (was %(oldrev_short)s)' + ) + +COMBINED_REFCHANGE_REVISION_SUBJECT_TEMPLATE = ( + '%(emailprefix)s%(refname_type)s %(short_refname)s updated: %(oneline)s' + ) + +REFCHANGE_HEADER_TEMPLATE = """\ +Date: %(send_date)s +To: %(recipients)s +Subject: %(subject)s +MIME-Version: 1.0 +Content-Type: text/%(contenttype)s; charset=%(charset)s +Content-Transfer-Encoding: 8bit +Message-ID: %(msgid)s +From: %(fromaddr)s +Reply-To: %(reply_to)s +Thread-Index: %(thread_index)s +X-Git-Host: %(fqdn)s +X-Git-Repo: %(repo_shortname)s +X-Git-Refname: %(refname)s +X-Git-Reftype: %(refname_type)s +X-Git-Oldrev: %(oldrev)s +X-Git-Newrev: %(newrev)s +X-Git-NotificationType: ref_changed +X-Git-Multimail-Version: %(multimail_version)s +Auto-Submitted: auto-generated +""" + +REFCHANGE_INTRO_TEMPLATE = """\ +This is an automated email from the git hooks/post-receive script. + +%(pusher)s pushed a change to %(refname_type)s %(short_refname)s +in repository %(repo_shortname)s. + +""" + + +FOOTER_TEMPLATE = """\ + +-- \n\ +To stop receiving notification emails like this one, please contact +%(administrator)s. +""" + + +REWIND_ONLY_TEMPLATE = """\ +This update removed existing revisions from the reference, leaving the +reference pointing at a previous point in the repository history. + + * -- * -- N %(refname)s (%(newrev_short)s) + \\ + O -- O -- O (%(oldrev_short)s) + +Any revisions marked "omit" are not gone; other references still +refer to them. Any revisions marked "discard" are gone forever. +""" + + +NON_FF_TEMPLATE = """\ +This update added new revisions after undoing existing revisions. +That is to say, some revisions that were in the old version of the +%(refname_type)s are not in the new version. This situation occurs +when a user --force pushes a change and generates a repository +containing something like this: + + * -- * -- B -- O -- O -- O (%(oldrev_short)s) + \\ + N -- N -- N %(refname)s (%(newrev_short)s) + +You should already have received notification emails for all of the O +revisions, and so the following emails describe only the N revisions +from the common base, B. + +Any revisions marked "omit" are not gone; other references still +refer to them. Any revisions marked "discard" are gone forever. +""" + + +NO_NEW_REVISIONS_TEMPLATE = """\ +No new revisions were added by this update. +""" + + +DISCARDED_REVISIONS_TEMPLATE = """\ +This change permanently discards the following revisions: +""" + + +NO_DISCARDED_REVISIONS_TEMPLATE = """\ +The revisions that were on this %(refname_type)s are still contained in +other references; therefore, this change does not discard any commits +from the repository. +""" + + +NEW_REVISIONS_TEMPLATE = """\ +The %(tot)s revisions listed above as "new" are entirely new to this +repository and will be described in separate emails. The revisions +listed as "add" were already present in the repository and have only +been added to this reference. + +""" + + +TAG_CREATED_TEMPLATE = """\ + at %(newrev_short)-8s (%(newrev_type)s) +""" + + +TAG_UPDATED_TEMPLATE = """\ +*** WARNING: tag %(short_refname)s was modified! *** + + from %(oldrev_short)-8s (%(oldrev_type)s) + to %(newrev_short)-8s (%(newrev_type)s) +""" + + +TAG_DELETED_TEMPLATE = """\ +*** WARNING: tag %(short_refname)s was deleted! *** + +""" + + +# The template used in summary tables. It looks best if this uses the +# same alignment as TAG_CREATED_TEMPLATE and TAG_UPDATED_TEMPLATE. +BRIEF_SUMMARY_TEMPLATE = """\ +%(action)8s %(rev_short)-8s %(text)s +""" + + +NON_COMMIT_UPDATE_TEMPLATE = """\ +This is an unusual reference change because the reference did not +refer to a commit either before or after the change. We do not know +how to provide full information about this reference change. +""" + + +REVISION_HEADER_TEMPLATE = """\ +Date: %(send_date)s +To: %(recipients)s +Cc: %(cc_recipients)s +Subject: %(emailprefix)s%(num)02d/%(tot)02d: %(oneline)s +MIME-Version: 1.0 +Content-Type: text/%(contenttype)s; charset=%(charset)s +Content-Transfer-Encoding: 8bit +From: %(fromaddr)s +Reply-To: %(reply_to)s +In-Reply-To: %(reply_to_msgid)s +References: %(reply_to_msgid)s +Thread-Index: %(thread_index)s +X-Git-Host: %(fqdn)s +X-Git-Repo: %(repo_shortname)s +X-Git-Refname: %(refname)s +X-Git-Reftype: %(refname_type)s +X-Git-Rev: %(rev)s +X-Git-NotificationType: diff +X-Git-Multimail-Version: %(multimail_version)s +Auto-Submitted: auto-generated +""" + +REVISION_INTRO_TEMPLATE = """\ +This is an automated email from the git hooks/post-receive script. + +%(pusher)s pushed a commit to %(refname_type)s %(short_refname)s +in repository %(repo_shortname)s. + +""" + +LINK_TEXT_TEMPLATE = """\ +View the commit online: +%(browse_url)s + +""" + +LINK_HTML_TEMPLATE = """\ +

View the commit online.

+""" + + +REVISION_FOOTER_TEMPLATE = FOOTER_TEMPLATE + + +# Combined, meaning refchange+revision email (for single-commit additions) +COMBINED_HEADER_TEMPLATE = """\ +Date: %(send_date)s +To: %(recipients)s +Subject: %(subject)s +MIME-Version: 1.0 +Content-Type: text/%(contenttype)s; charset=%(charset)s +Content-Transfer-Encoding: 8bit +Message-ID: %(msgid)s +From: %(fromaddr)s +Reply-To: %(reply_to)s +X-Git-Host: %(fqdn)s +X-Git-Repo: %(repo_shortname)s +X-Git-Refname: %(refname)s +X-Git-Reftype: %(refname_type)s +X-Git-Oldrev: %(oldrev)s +X-Git-Newrev: %(newrev)s +X-Git-Rev: %(rev)s +X-Git-NotificationType: ref_changed_plus_diff +X-Git-Multimail-Version: %(multimail_version)s +Auto-Submitted: auto-generated +""" + +COMBINED_INTRO_TEMPLATE = """\ +This is an automated email from the git hooks/post-receive script. + +%(pusher)s pushed a commit to %(refname_type)s %(short_refname)s +in repository %(repo_shortname)s. + +""" + +COMBINED_FOOTER_TEMPLATE = FOOTER_TEMPLATE + + +class CommandError(Exception): + def __init__(self, cmd, retcode): + self.cmd = cmd + self.retcode = retcode + Exception.__init__( + self, + 'Command "%s" failed with retcode %s' % (' '.join(cmd), retcode,) + ) + + +class ConfigurationException(Exception): + pass + + +# The "git" program (this could be changed to include a full path): +GIT_EXECUTABLE = 'git' + + +# How "git" should be invoked (including global arguments), as a list +# of words. This variable is usually initialized automatically by +# read_git_output() via choose_git_command(), but if a value is set +# here then it will be used unconditionally. +GIT_CMD = None + + +def choose_git_command(): + """Decide how to invoke git, and record the choice in GIT_CMD.""" + + global GIT_CMD + + if GIT_CMD is None: + try: + # Check to see whether the "-c" option is accepted (it was + # only added in Git 1.7.2). We don't actually use the + # output of "git --version", though if we needed more + # specific version information this would be the place to + # do it. + cmd = [GIT_EXECUTABLE, '-c', 'foo.bar=baz', '--version'] + read_output(cmd) + GIT_CMD = [GIT_EXECUTABLE, '-c', 'i18n.logoutputencoding=%s' % (ENCODING,)] + except CommandError: + GIT_CMD = [GIT_EXECUTABLE] + + +def read_git_output(args, input=None, keepends=False, **kw): + """Read the output of a Git command.""" + + if GIT_CMD is None: + choose_git_command() + + return read_output(GIT_CMD + args, input=input, keepends=keepends, **kw) + + +def read_output(cmd, input=None, keepends=False, **kw): + if input: + stdin = subprocess.PIPE + input = str_to_bytes(input) + else: + stdin = None + errors = 'strict' + if 'errors' in kw: + errors = kw['errors'] + del kw['errors'] + p = subprocess.Popen( + tuple(str_to_bytes(w) for w in cmd), + stdin=stdin, stdout=subprocess.PIPE, stderr=subprocess.PIPE, **kw + ) + (out, err) = p.communicate(input) + out = bytes_to_str(out, errors=errors) + retcode = p.wait() + if retcode: + raise CommandError(cmd, retcode) + if not keepends: + out = out.rstrip('\n\r') + return out + + +def read_git_lines(args, keepends=False, **kw): + """Return the lines output by Git command. + + Return as single lines, with newlines stripped off.""" + + return read_git_output(args, keepends=True, **kw).splitlines(keepends) + + +def git_rev_list_ish(cmd, spec, args=None, **kw): + """Common functionality for invoking a 'git rev-list'-like command. + + Parameters: + * cmd is the Git command to run, e.g., 'rev-list' or 'log'. + * spec is a list of revision arguments to pass to the named + command. If None, this function returns an empty list. + * args is a list of extra arguments passed to the named command. + * All other keyword arguments (if any) are passed to the + underlying read_git_lines() function. + + Return the output of the Git command in the form of a list, one + entry per output line. + """ + if spec is None: + return [] + if args is None: + args = [] + args = [cmd, '--stdin'] + args + spec_stdin = ''.join(s + '\n' for s in spec) + return read_git_lines(args, input=spec_stdin, **kw) + + +def git_rev_list(spec, **kw): + """Run 'git rev-list' with the given list of revision arguments. + + See git_rev_list_ish() for parameter and return value + documentation. + """ + return git_rev_list_ish('rev-list', spec, **kw) + + +def git_log(spec, **kw): + """Run 'git log' with the given list of revision arguments. + + See git_rev_list_ish() for parameter and return value + documentation. + """ + return git_rev_list_ish('log', spec, **kw) + + +def header_encode(text, header_name=None): + """Encode and line-wrap the value of an email header field.""" + + # Convert to unicode, if required. + if not isinstance(text, unicode): + text = unicode(text, 'utf-8') + + if is_ascii(text): + charset = 'ascii' + else: + charset = 'utf-8' + + return Header(text, header_name=header_name, charset=Charset(charset)).encode() + + +def addr_header_encode(text, header_name=None): + """Encode and line-wrap the value of an email header field containing + email addresses.""" + + # Convert to unicode, if required. + if not isinstance(text, unicode): + text = unicode(text, 'utf-8') + + text = ', '.join( + formataddr((header_encode(name), emailaddr)) + for name, emailaddr in getaddresses([text]) + ) + + if is_ascii(text): + charset = 'ascii' + else: + charset = 'utf-8' + + return Header(text, header_name=header_name, charset=Charset(charset)).encode() + + +class Config(object): + def __init__(self, section, git_config=None): + """Represent a section of the git configuration. + + If git_config is specified, it is passed to "git config" in + the GIT_CONFIG environment variable, meaning that "git config" + will read the specified path rather than the Git default + config paths.""" + + self.section = section + if git_config: + self.env = os.environ.copy() + self.env['GIT_CONFIG'] = git_config + else: + self.env = None + + @staticmethod + def _split(s): + """Split NUL-terminated values.""" + + words = s.split('\0') + assert words[-1] == '' + return words[:-1] + + @staticmethod + def add_config_parameters(c): + """Add configuration parameters to Git. + + c is either an str or a list of str, each element being of the + form 'var=val' or 'var', with the same syntax and meaning as + the argument of 'git -c var=val'. + """ + if isinstance(c, str): + c = (c,) + parameters = os.environ.get('GIT_CONFIG_PARAMETERS', '') + if parameters: + parameters += ' ' + # git expects GIT_CONFIG_PARAMETERS to be of the form + # "'name1=value1' 'name2=value2' 'name3=value3'" + # including everything inside the double quotes (but not the double + # quotes themselves). Spacing is critical. Also, if a value contains + # a literal single quote that quote must be represented using the + # four character sequence: '\'' + parameters += ' '.join("'" + x.replace("'", "'\\''") + "'" for x in c) + os.environ['GIT_CONFIG_PARAMETERS'] = parameters + + def get(self, name, default=None): + try: + values = self._split(read_git_output( + ['config', '--get', '--null', '%s.%s' % (self.section, name)], + env=self.env, keepends=True, + )) + assert len(values) == 1 + return values[0] + except CommandError: + return default + + def get_bool(self, name, default=None): + try: + value = read_git_output( + ['config', '--get', '--bool', '%s.%s' % (self.section, name)], + env=self.env, + ) + except CommandError: + return default + return value == 'true' + + def get_all(self, name, default=None): + """Read a (possibly multivalued) setting from the configuration. + + Return the result as a list of values, or default if the name + is unset.""" + + try: + return self._split(read_git_output( + ['config', '--get-all', '--null', '%s.%s' % (self.section, name)], + env=self.env, keepends=True, + )) + except CommandError: + t, e, traceback = sys.exc_info() + if e.retcode == 1: + # "the section or key is invalid"; i.e., there is no + # value for the specified key. + return default + else: + raise + + def set(self, name, value): + read_git_output( + ['config', '%s.%s' % (self.section, name), value], + env=self.env, + ) + + def add(self, name, value): + read_git_output( + ['config', '--add', '%s.%s' % (self.section, name), value], + env=self.env, + ) + + def __contains__(self, name): + return self.get_all(name, default=None) is not None + + # We don't use this method anymore internally, but keep it here in + # case somebody is calling it from their own code: + def has_key(self, name): + return name in self + + def unset_all(self, name): + try: + read_git_output( + ['config', '--unset-all', '%s.%s' % (self.section, name)], + env=self.env, + ) + except CommandError: + t, e, traceback = sys.exc_info() + if e.retcode == 5: + # The name doesn't exist, which is what we wanted anyway... + pass + else: + raise + + def set_recipients(self, name, value): + self.unset_all(name) + for pair in getaddresses([value]): + self.add(name, formataddr(pair)) + + +def generate_summaries(*log_args): + """Generate a brief summary for each revision requested. + + log_args are strings that will be passed directly to "git log" as + revision selectors. Iterate over (sha1_short, subject) for each + commit specified by log_args (subject is the first line of the + commit message as a string without EOLs).""" + + cmd = [ + 'log', '--abbrev', '--format=%h %s', + ] + list(log_args) + ['--'] + for line in read_git_lines(cmd): + yield tuple(line.split(' ', 1)) + + +def limit_lines(lines, max_lines): + for (index, line) in enumerate(lines): + if index < max_lines: + yield line + + if index >= max_lines: + yield '... %d lines suppressed ...\n' % (index + 1 - max_lines,) + + +def limit_linelength(lines, max_linelength): + for line in lines: + # Don't forget that lines always include a trailing newline. + if len(line) > max_linelength + 1: + line = line[:max_linelength - 7] + ' [...]\n' + yield line + + +class CommitSet(object): + """A (constant) set of object names. + + The set should be initialized with full SHA1 object names. The + __contains__() method returns True iff its argument is an + abbreviation of any the names in the set.""" + + def __init__(self, names): + self._names = sorted(names) + + def __len__(self): + return len(self._names) + + def __contains__(self, sha1_abbrev): + """Return True iff this set contains sha1_abbrev (which might be abbreviated).""" + + i = bisect.bisect_left(self._names, sha1_abbrev) + return i < len(self) and self._names[i].startswith(sha1_abbrev) + + +class GitObject(object): + def __init__(self, sha1, type=None): + if sha1 == ZEROS: + self.sha1 = self.type = self.commit_sha1 = None + else: + self.sha1 = sha1 + self.type = type or read_git_output(['cat-file', '-t', self.sha1]) + + if self.type == 'commit': + self.commit_sha1 = self.sha1 + elif self.type == 'tag': + try: + self.commit_sha1 = read_git_output( + ['rev-parse', '--verify', '%s^0' % (self.sha1,)] + ) + except CommandError: + # Cannot deref tag to determine commit_sha1 + self.commit_sha1 = None + else: + self.commit_sha1 = None + + self.short = read_git_output(['rev-parse', '--short', sha1]) + + def get_summary(self): + """Return (sha1_short, subject) for this commit.""" + + if not self.sha1: + raise ValueError('Empty commit has no summary') + + return next(iter(generate_summaries('--no-walk', self.sha1))) + + def __eq__(self, other): + return isinstance(other, GitObject) and self.sha1 == other.sha1 + + def __ne__(self, other): + return not self == other + + def __hash__(self): + return hash(self.sha1) + + def __nonzero__(self): + return bool(self.sha1) + + def __bool__(self): + """Python 2 backward compatibility""" + return self.__nonzero__() + + def __str__(self): + return self.sha1 or ZEROS + + +class Change(object): + """A Change that has been made to the Git repository. + + Abstract class from which both Revisions and ReferenceChanges are + derived. A Change knows how to generate a notification email + describing itself.""" + + def __init__(self, environment): + self.environment = environment + self._values = None + self._contains_html_diff = False + + def _contains_diff(self): + # We do contain a diff, should it be rendered in HTML? + if self.environment.commit_email_format == "html": + self._contains_html_diff = True + + def _compute_values(self): + """Return a dictionary {keyword: expansion} for this Change. + + Derived classes overload this method to add more entries to + the return value. This method is used internally by + get_values(). The return value should always be a new + dictionary.""" + + values = self.environment.get_values() + fromaddr = self.environment.get_fromaddr(change=self) + if fromaddr is not None: + values['fromaddr'] = fromaddr + values['multimail_version'] = get_version() + return values + + # Aliases usable in template strings. Tuple of pairs (destination, + # source). + VALUES_ALIAS = ( + ("id", "newrev"), + ) + + def get_values(self, **extra_values): + """Return a dictionary {keyword: expansion} for this Change. + + Return a dictionary mapping keywords to the values that they + should be expanded to for this Change (used when interpolating + template strings). If any keyword arguments are supplied, add + those to the return value as well. The return value is always + a new dictionary.""" + + if self._values is None: + self._values = self._compute_values() + + values = self._values.copy() + if extra_values: + values.update(extra_values) + + for alias, val in self.VALUES_ALIAS: + values[alias] = values[val] + return values + + def expand(self, template, **extra_values): + """Expand template. + + Expand the template (which should be a string) using string + interpolation of the values for this Change. If any keyword + arguments are provided, also include those in the keywords + available for interpolation.""" + + return template % self.get_values(**extra_values) + + def expand_lines(self, template, html_escape_val=False, **extra_values): + """Break template into lines and expand each line.""" + + values = self.get_values(**extra_values) + if html_escape_val: + for k in values: + if is_string(values[k]): + values[k] = html_escape(values[k]) + for line in template.splitlines(True): + yield line % values + + def expand_header_lines(self, template, **extra_values): + """Break template into lines and expand each line as an RFC 2822 header. + + Encode values and split up lines that are too long. Silently + skip lines that contain references to unknown variables.""" + + values = self.get_values(**extra_values) + if self._contains_html_diff: + self._content_type = 'html' + else: + self._content_type = 'plain' + values['contenttype'] = self._content_type + + for line in template.splitlines(): + (name, value) = line.split(': ', 1) + + try: + value = value % values + except KeyError: + t, e, traceback = sys.exc_info() + if DEBUG: + self.environment.log_warning( + 'Warning: unknown variable %r in the following line; line skipped:\n' + ' %s\n' + % (e.args[0], line,) + ) + else: + if name.lower() in ADDR_HEADERS: + value = addr_header_encode(value, name) + else: + value = header_encode(value, name) + for splitline in ('%s: %s\n' % (name, value)).splitlines(True): + yield splitline + + def generate_email_header(self): + """Generate the RFC 2822 email headers for this Change, a line at a time. + + The output should not include the trailing blank line.""" + + raise NotImplementedError() + + def generate_browse_link(self, base_url): + """Generate a link to an online repository browser.""" + return iter(()) + + def generate_email_intro(self, html_escape_val=False): + """Generate the email intro for this Change, a line at a time. + + The output will be used as the standard boilerplate at the top + of the email body.""" + + raise NotImplementedError() + + def generate_email_body(self, push): + """Generate the main part of the email body, a line at a time. + + The text in the body might be truncated after a specified + number of lines (see multimailhook.emailmaxlines).""" + + raise NotImplementedError() + + def generate_email_footer(self, html_escape_val): + """Generate the footer of the email, a line at a time. + + The footer is always included, irrespective of + multimailhook.emailmaxlines.""" + + raise NotImplementedError() + + def _wrap_for_html(self, lines): + """Wrap the lines in HTML 
 tag when using HTML format.
+
+        Escape special HTML characters and add 
 and 
 tags around
+        the given lines if we should be generating HTML as indicated by
+        self._contains_html_diff being set to true.
+        """
+        if self._contains_html_diff:
+            yield "
\n"
+
+            for line in lines:
+                yield html_escape(line)
+
+            yield '
\n'
+        else:
+            for line in lines:
+                yield line
+
+    def generate_email(self, push, body_filter=None, extra_header_values={}):
+        """Generate an email describing this change.
+
+        Iterate over the lines (including the header lines) of an
+        email describing this change.  If body_filter is not None,
+        then use it to filter the lines that are intended for the
+        email body.
+
+        The extra_header_values field is received as a dict and not as
+        **kwargs, to allow passing other keyword arguments in the
+        future (e.g. passing extra values to generate_email_intro()"""
+
+        for line in self.generate_email_header(**extra_header_values):
+            yield line
+        yield '\n'
+        html_escape_val = (self.environment.html_in_intro and
+                           self._contains_html_diff)
+        intro = self.generate_email_intro(html_escape_val)
+        if not self.environment.html_in_intro:
+            intro = self._wrap_for_html(intro)
+        for line in intro:
+            yield line
+
+        if self.environment.commitBrowseURL:
+            for line in self.generate_browse_link(self.environment.commitBrowseURL):
+                yield line
+
+        body = self.generate_email_body(push)
+        if body_filter is not None:
+            body = body_filter(body)
+
+        diff_started = False
+        if self._contains_html_diff:
+            # "white-space: pre" is the default, but we need to
+            # specify it again in case the message is viewed in a
+            # webmail which wraps it in an element setting white-space
+            # to something else (Zimbra does this and sets
+            # white-space: pre-line).
+            yield '
'
+        for line in body:
+            if self._contains_html_diff:
+                # This is very, very naive. It would be much better to really
+                # parse the diff, i.e. look at how many lines do we have in
+                # the hunk headers instead of blindly highlighting everything
+                # that looks like it might be part of a diff.
+                bgcolor = ''
+                fgcolor = ''
+                if line.startswith('--- a/'):
+                    diff_started = True
+                    bgcolor = 'e0e0ff'
+                elif line.startswith('diff ') or line.startswith('index '):
+                    diff_started = True
+                    fgcolor = '808080'
+                elif diff_started:
+                    if line.startswith('+++ '):
+                        bgcolor = 'e0e0ff'
+                    elif line.startswith('@@'):
+                        bgcolor = 'e0e0e0'
+                    elif line.startswith('+'):
+                        bgcolor = 'e0ffe0'
+                    elif line.startswith('-'):
+                        bgcolor = 'ffe0e0'
+                elif line.startswith('commit '):
+                    fgcolor = '808000'
+                elif line.startswith('    '):
+                    fgcolor = '404040'
+
+                # Chop the trailing LF, we don't want it inside 
.
+                line = html_escape(line[:-1])
+
+                if bgcolor or fgcolor:
+                    style = 'display:block; white-space:pre;'
+                    if bgcolor:
+                        style += 'background:#' + bgcolor + ';'
+                    if fgcolor:
+                        style += 'color:#' + fgcolor + ';'
+                    # Use a %s\n" % (style, line)
+                else:
+                    line = line + '\n'
+
+            yield line
+        if self._contains_html_diff:
+            yield '
'
+        html_escape_val = (self.environment.html_in_footer and
+                           self._contains_html_diff)
+        footer = self.generate_email_footer(html_escape_val)
+        if not self.environment.html_in_footer:
+            footer = self._wrap_for_html(footer)
+        for line in footer:
+            yield line
+
+    def get_specific_fromaddr(self):
+        """For kinds of Changes which specify it, return the kind-specific
+        From address to use."""
+        return None
+
+
+class Revision(Change):
+    """A Change consisting of a single git commit."""
+
+    CC_RE = re.compile(r'^\s*C[Cc]:\s*(?P[^#]+@[^\s#]*)\s*(#.*)?$')
+
+    def __init__(self, reference_change, rev, num, tot):
+        Change.__init__(self, reference_change.environment)
+        self.reference_change = reference_change
+        self.rev = rev
+        self.change_type = self.reference_change.change_type
+        self.refname = self.reference_change.refname
+        self.num = num
+        self.tot = tot
+        self.author = read_git_output(['log', '--no-walk', '--format=%aN <%aE>', self.rev.sha1])
+        self.recipients = self.environment.get_revision_recipients(self)
+
+        # -s is short for --no-patch, but -s works on older git's (e.g. 1.7)
+        self.parents = read_git_lines(['show', '-s', '--format=%P',
+                                      self.rev.sha1])[0].split()
+
+        self.cc_recipients = ''
+        if self.environment.get_scancommitforcc():
+            self.cc_recipients = ', '.join(to.strip() for to in self._cc_recipients())
+            if self.cc_recipients:
+                self.environment.log_msg(
+                    'Add %s to CC for %s' % (self.cc_recipients, self.rev.sha1))
+
+    def _cc_recipients(self):
+        cc_recipients = []
+        message = read_git_output(['log', '--no-walk', '--format=%b', self.rev.sha1])
+        lines = message.strip().split('\n')
+        for line in lines:
+            m = re.match(self.CC_RE, line)
+            if m:
+                cc_recipients.append(m.group('to'))
+
+        return cc_recipients
+
+    def _compute_values(self):
+        values = Change._compute_values(self)
+
+        oneline = read_git_output(
+            ['log', '--format=%s', '--no-walk', self.rev.sha1]
+            )
+
+        max_subject_length = self.environment.get_max_subject_length()
+        if max_subject_length > 0 and len(oneline) > max_subject_length:
+            oneline = oneline[:max_subject_length - 6] + ' [...]'
+
+        values['rev'] = self.rev.sha1
+        values['parents'] = ' '.join(self.parents)
+        values['rev_short'] = self.rev.short
+        values['change_type'] = self.change_type
+        values['refname'] = self.refname
+        values['newrev'] = self.rev.sha1
+        values['short_refname'] = self.reference_change.short_refname
+        values['refname_type'] = self.reference_change.refname_type
+        values['reply_to_msgid'] = self.reference_change.msgid
+        values['thread_index'] = self.reference_change.thread_index
+        values['num'] = self.num
+        values['tot'] = self.tot
+        values['recipients'] = self.recipients
+        if self.cc_recipients:
+            values['cc_recipients'] = self.cc_recipients
+        values['oneline'] = oneline
+        values['author'] = self.author
+
+        reply_to = self.environment.get_reply_to_commit(self)
+        if reply_to:
+            values['reply_to'] = reply_to
+
+        return values
+
+    def generate_email_header(self, **extra_values):
+        for line in self.expand_header_lines(
+                REVISION_HEADER_TEMPLATE, **extra_values
+                ):
+            yield line
+
+    def generate_browse_link(self, base_url):
+        if '%(' not in base_url:
+            base_url += '%(id)s'
+        url = "".join(self.expand_lines(base_url))
+        if self._content_type == 'html':
+            for line in self.expand_lines(LINK_HTML_TEMPLATE,
+                                          html_escape_val=True,
+                                          browse_url=url):
+                yield line
+        elif self._content_type == 'plain':
+            for line in self.expand_lines(LINK_TEXT_TEMPLATE,
+                                          html_escape_val=False,
+                                          browse_url=url):
+                yield line
+        else:
+            raise NotImplementedError("Content-type %s unsupported. Please report it as a bug.")
+
+    def generate_email_intro(self, html_escape_val=False):
+        for line in self.expand_lines(REVISION_INTRO_TEMPLATE,
+                                      html_escape_val=html_escape_val):
+            yield line
+
+    def generate_email_body(self, push):
+        """Show this revision."""
+
+        for line in read_git_lines(
+                ['log'] + self.environment.commitlogopts + ['-1', self.rev.sha1],
+                keepends=True,
+                errors='replace'):
+            if line.startswith('Date:   ') and self.environment.date_substitute:
+                yield self.environment.date_substitute + line[len('Date:   '):]
+            else:
+                yield line
+
+    def generate_email_footer(self, html_escape_val):
+        return self.expand_lines(REVISION_FOOTER_TEMPLATE,
+                                 html_escape_val=html_escape_val)
+
+    def generate_email(self, push, body_filter=None, extra_header_values={}):
+        self._contains_diff()
+        return Change.generate_email(self, push, body_filter, extra_header_values)
+
+    def get_specific_fromaddr(self):
+        return self.environment.from_commit
+
+
+class ReferenceChange(Change):
+    """A Change to a Git reference.
+
+    An abstract class representing a create, update, or delete of a
+    Git reference.  Derived classes handle specific types of reference
+    (e.g., tags vs. branches).  These classes generate the main
+    reference change email summarizing the reference change and
+    whether it caused any any commits to be added or removed.
+
+    ReferenceChange objects are usually created using the static
+    create() method, which has the logic to decide which derived class
+    to instantiate."""
+
+    REF_RE = re.compile(r'^refs\/(?P[^\/]+)\/(?P.*)$')
+
+    @staticmethod
+    def create(environment, oldrev, newrev, refname):
+        """Return a ReferenceChange object representing the change.
+
+        Return an object that represents the type of change that is being
+        made. oldrev and newrev should be SHA1s or ZEROS."""
+
+        old = GitObject(oldrev)
+        new = GitObject(newrev)
+        rev = new or old
+
+        # The revision type tells us what type the commit is, combined with
+        # the location of the ref we can decide between
+        #  - working branch
+        #  - tracking branch
+        #  - unannotated tag
+        #  - annotated tag
+        m = ReferenceChange.REF_RE.match(refname)
+        if m:
+            area = m.group('area')
+            short_refname = m.group('shortname')
+        else:
+            area = ''
+            short_refname = refname
+
+        if rev.type == 'tag':
+            # Annotated tag:
+            klass = AnnotatedTagChange
+        elif rev.type == 'commit':
+            if area == 'tags':
+                # Non-annotated tag:
+                klass = NonAnnotatedTagChange
+            elif area == 'heads':
+                # Branch:
+                klass = BranchChange
+            elif area == 'remotes':
+                # Tracking branch:
+                environment.log_warning(
+                    '*** Push-update of tracking branch %r\n'
+                    '***  - incomplete email generated.'
+                    % (refname,)
+                    )
+                klass = OtherReferenceChange
+            else:
+                # Some other reference namespace:
+                environment.log_warning(
+                    '*** Push-update of strange reference %r\n'
+                    '***  - incomplete email generated.'
+                    % (refname,)
+                    )
+                klass = OtherReferenceChange
+        else:
+            # Anything else (is there anything else?)
+            environment.log_warning(
+                '*** Unknown type of update to %r (%s)\n'
+                '***  - incomplete email generated.'
+                % (refname, rev.type,)
+                )
+            klass = OtherReferenceChange
+
+        return klass(
+            environment,
+            refname=refname, short_refname=short_refname,
+            old=old, new=new, rev=rev,
+            )
+
+    @staticmethod
+    def make_thread_index():
+        """Return a string appropriate for the Thread-Index header,
+        needed by MS Outlook to get threading right.
+
+        The format is (base64-encoded):
+        - 1 byte must be 1
+        - 5 bytes encode a date (hardcoded here)
+        - 16 bytes for a globally unique identifier
+
+        FIXME: Unfortunately, even with the Thread-Index field, MS
+        Outlook doesn't seem to do the threading reliably (see
+        https://github.com/git-multimail/git-multimail/pull/194).
+        """
+        thread_index = b'\x01\x00\x00\x12\x34\x56' + uuid.uuid4().bytes
+        return base64.standard_b64encode(thread_index).decode('ascii')
+
+    def __init__(self, environment, refname, short_refname, old, new, rev):
+        Change.__init__(self, environment)
+        self.change_type = {
+            (False, True): 'create',
+            (True, True): 'update',
+            (True, False): 'delete',
+            }[bool(old), bool(new)]
+        self.refname = refname
+        self.short_refname = short_refname
+        self.old = old
+        self.new = new
+        self.rev = rev
+        self.msgid = make_msgid()
+        self.thread_index = self.make_thread_index()
+        self.diffopts = environment.diffopts
+        self.graphopts = environment.graphopts
+        self.logopts = environment.logopts
+        self.commitlogopts = environment.commitlogopts
+        self.showgraph = environment.refchange_showgraph
+        self.showlog = environment.refchange_showlog
+
+        self.header_template = REFCHANGE_HEADER_TEMPLATE
+        self.intro_template = REFCHANGE_INTRO_TEMPLATE
+        self.footer_template = FOOTER_TEMPLATE
+
+    def _compute_values(self):
+        values = Change._compute_values(self)
+
+        values['change_type'] = self.change_type
+        values['refname_type'] = self.refname_type
+        values['refname'] = self.refname
+        values['short_refname'] = self.short_refname
+        values['msgid'] = self.msgid
+        values['thread_index'] = self.thread_index
+        values['recipients'] = self.recipients
+        values['oldrev'] = str(self.old)
+        values['oldrev_short'] = self.old.short
+        values['newrev'] = str(self.new)
+        values['newrev_short'] = self.new.short
+
+        if self.old:
+            values['oldrev_type'] = self.old.type
+        if self.new:
+            values['newrev_type'] = self.new.type
+
+        reply_to = self.environment.get_reply_to_refchange(self)
+        if reply_to:
+            values['reply_to'] = reply_to
+
+        return values
+
+    def send_single_combined_email(self, known_added_sha1s):
+        """Determine if a combined refchange/revision email should be sent
+
+        If there is only a single new (non-merge) commit added by a
+        change, it is useful to combine the ReferenceChange and
+        Revision emails into one.  In such a case, return the single
+        revision; otherwise, return None.
+
+        This method is overridden in BranchChange."""
+
+        return None
+
+    def generate_combined_email(self, push, revision, body_filter=None, extra_header_values={}):
+        """Generate an email describing this change AND specified revision.
+
+        Iterate over the lines (including the header lines) of an
+        email describing this change.  If body_filter is not None,
+        then use it to filter the lines that are intended for the
+        email body.
+
+        The extra_header_values field is received as a dict and not as
+        **kwargs, to allow passing other keyword arguments in the
+        future (e.g. passing extra values to generate_email_intro()
+
+        This method is overridden in BranchChange."""
+
+        raise NotImplementedError
+
+    def get_subject(self):
+        template = {
+            'create': REF_CREATED_SUBJECT_TEMPLATE,
+            'update': REF_UPDATED_SUBJECT_TEMPLATE,
+            'delete': REF_DELETED_SUBJECT_TEMPLATE,
+            }[self.change_type]
+        return self.expand(template)
+
+    def generate_email_header(self, **extra_values):
+        if 'subject' not in extra_values:
+            extra_values['subject'] = self.get_subject()
+
+        for line in self.expand_header_lines(
+                self.header_template, **extra_values
+                ):
+            yield line
+
+    def generate_email_intro(self, html_escape_val=False):
+        for line in self.expand_lines(self.intro_template,
+                                      html_escape_val=html_escape_val):
+            yield line
+
+    def generate_email_body(self, push):
+        """Call the appropriate body-generation routine.
+
+        Call one of generate_create_summary() /
+        generate_update_summary() / generate_delete_summary()."""
+
+        change_summary = {
+            'create': self.generate_create_summary,
+            'delete': self.generate_delete_summary,
+            'update': self.generate_update_summary,
+            }[self.change_type](push)
+        for line in change_summary:
+            yield line
+
+        for line in self.generate_revision_change_summary(push):
+            yield line
+
+    def generate_email_footer(self, html_escape_val):
+        return self.expand_lines(self.footer_template,
+                                 html_escape_val=html_escape_val)
+
+    def generate_revision_change_graph(self, push):
+        if self.showgraph:
+            args = ['--graph'] + self.graphopts
+            for newold in ('new', 'old'):
+                has_newold = False
+                spec = push.get_commits_spec(newold, self)
+                for line in git_log(spec, args=args, keepends=True):
+                    if not has_newold:
+                        has_newold = True
+                        yield '\n'
+                        yield 'Graph of %s commits:\n\n' % (
+                            {'new': 'new', 'old': 'discarded'}[newold],)
+                    yield '  ' + line
+                if has_newold:
+                    yield '\n'
+
+    def generate_revision_change_log(self, new_commits_list):
+        if self.showlog:
+            yield '\n'
+            yield 'Detailed log of new commits:\n\n'
+            for line in read_git_lines(
+                    ['log', '--no-walk'] +
+                    self.logopts +
+                    new_commits_list +
+                    ['--'],
+                    keepends=True,
+                    ):
+                yield line
+
+    def generate_new_revision_summary(self, tot, new_commits_list, push):
+        for line in self.expand_lines(NEW_REVISIONS_TEMPLATE, tot=tot):
+            yield line
+        for line in self.generate_revision_change_graph(push):
+            yield line
+        for line in self.generate_revision_change_log(new_commits_list):
+            yield line
+
+    def generate_revision_change_summary(self, push):
+        """Generate a summary of the revisions added/removed by this change."""
+
+        if self.new.commit_sha1 and not self.old.commit_sha1:
+            # A new reference was created.  List the new revisions
+            # brought by the new reference (i.e., those revisions that
+            # were not in the repository before this reference
+            # change).
+            sha1s = list(push.get_new_commits(self))
+            sha1s.reverse()
+            tot = len(sha1s)
+            new_revisions = [
+                Revision(self, GitObject(sha1), num=i + 1, tot=tot)
+                for (i, sha1) in enumerate(sha1s)
+                ]
+
+            if new_revisions:
+                yield self.expand('This %(refname_type)s includes the following new commits:\n')
+                yield '\n'
+                for r in new_revisions:
+                    (sha1, subject) = r.rev.get_summary()
+                    yield r.expand(
+                        BRIEF_SUMMARY_TEMPLATE, action='new', text=subject,
+                        )
+                yield '\n'
+                for line in self.generate_new_revision_summary(
+                        tot, [r.rev.sha1 for r in new_revisions], push):
+                    yield line
+            else:
+                for line in self.expand_lines(NO_NEW_REVISIONS_TEMPLATE):
+                    yield line
+
+        elif self.new.commit_sha1 and self.old.commit_sha1:
+            # A reference was changed to point at a different commit.
+            # List the revisions that were removed and/or added *from
+            # that reference* by this reference change, along with a
+            # diff between the trees for its old and new values.
+
+            # List of the revisions that were added to the branch by
+            # this update.  Note this list can include revisions that
+            # have already had notification emails; we want such
+            # revisions in the summary even though we will not send
+            # new notification emails for them.
+            adds = list(generate_summaries(
+                '--topo-order', '--reverse', '%s..%s'
+                % (self.old.commit_sha1, self.new.commit_sha1,)
+                ))
+
+            # List of the revisions that were removed from the branch
+            # by this update.  This will be empty except for
+            # non-fast-forward updates.
+            discards = list(generate_summaries(
+                '%s..%s' % (self.new.commit_sha1, self.old.commit_sha1,)
+                ))
+
+            if adds:
+                new_commits_list = push.get_new_commits(self)
+            else:
+                new_commits_list = []
+            new_commits = CommitSet(new_commits_list)
+
+            if discards:
+                discarded_commits = CommitSet(push.get_discarded_commits(self))
+            else:
+                discarded_commits = CommitSet([])
+
+            if discards and adds:
+                for (sha1, subject) in discards:
+                    if sha1 in discarded_commits:
+                        action = 'discard'
+                    else:
+                        action = 'omit'
+                    yield self.expand(
+                        BRIEF_SUMMARY_TEMPLATE, action=action,
+                        rev_short=sha1, text=subject,
+                        )
+                for (sha1, subject) in adds:
+                    if sha1 in new_commits:
+                        action = 'new'
+                    else:
+                        action = 'add'
+                    yield self.expand(
+                        BRIEF_SUMMARY_TEMPLATE, action=action,
+                        rev_short=sha1, text=subject,
+                        )
+                yield '\n'
+                for line in self.expand_lines(NON_FF_TEMPLATE):
+                    yield line
+
+            elif discards:
+                for (sha1, subject) in discards:
+                    if sha1 in discarded_commits:
+                        action = 'discard'
+                    else:
+                        action = 'omit'
+                    yield self.expand(
+                        BRIEF_SUMMARY_TEMPLATE, action=action,
+                        rev_short=sha1, text=subject,
+                        )
+                yield '\n'
+                for line in self.expand_lines(REWIND_ONLY_TEMPLATE):
+                    yield line
+
+            elif adds:
+                (sha1, subject) = self.old.get_summary()
+                yield self.expand(
+                    BRIEF_SUMMARY_TEMPLATE, action='from',
+                    rev_short=sha1, text=subject,
+                    )
+                for (sha1, subject) in adds:
+                    if sha1 in new_commits:
+                        action = 'new'
+                    else:
+                        action = 'add'
+                    yield self.expand(
+                        BRIEF_SUMMARY_TEMPLATE, action=action,
+                        rev_short=sha1, text=subject,
+                        )
+
+            yield '\n'
+
+            if new_commits:
+                for line in self.generate_new_revision_summary(
+                        len(new_commits), new_commits_list, push):
+                    yield line
+            else:
+                for line in self.expand_lines(NO_NEW_REVISIONS_TEMPLATE):
+                    yield line
+                for line in self.generate_revision_change_graph(push):
+                    yield line
+
+            # The diffstat is shown from the old revision to the new
+            # revision.  This is to show the truth of what happened in
+            # this change.  There's no point showing the stat from the
+            # base to the new revision because the base is effectively a
+            # random revision at this point - the user will be interested
+            # in what this revision changed - including the undoing of
+            # previous revisions in the case of non-fast-forward updates.
+            yield '\n'
+            yield 'Summary of changes:\n'
+            for line in read_git_lines(
+                    ['diff-tree'] +
+                    self.diffopts +
+                    ['%s..%s' % (self.old.commit_sha1, self.new.commit_sha1,)],
+                    keepends=True,
+                    ):
+                yield line
+
+        elif self.old.commit_sha1 and not self.new.commit_sha1:
+            # A reference was deleted.  List the revisions that were
+            # removed from the repository by this reference change.
+
+            sha1s = list(push.get_discarded_commits(self))
+            tot = len(sha1s)
+            discarded_revisions = [
+                Revision(self, GitObject(sha1), num=i + 1, tot=tot)
+                for (i, sha1) in enumerate(sha1s)
+                ]
+
+            if discarded_revisions:
+                for line in self.expand_lines(DISCARDED_REVISIONS_TEMPLATE):
+                    yield line
+                yield '\n'
+                for r in discarded_revisions:
+                    (sha1, subject) = r.rev.get_summary()
+                    yield r.expand(
+                        BRIEF_SUMMARY_TEMPLATE, action='discard', text=subject,
+                        )
+                for line in self.generate_revision_change_graph(push):
+                    yield line
+            else:
+                for line in self.expand_lines(NO_DISCARDED_REVISIONS_TEMPLATE):
+                    yield line
+
+        elif not self.old.commit_sha1 and not self.new.commit_sha1:
+            for line in self.expand_lines(NON_COMMIT_UPDATE_TEMPLATE):
+                yield line
+
+    def generate_create_summary(self, push):
+        """Called for the creation of a reference."""
+
+        # This is a new reference and so oldrev is not valid
+        (sha1, subject) = self.new.get_summary()
+        yield self.expand(
+            BRIEF_SUMMARY_TEMPLATE, action='at',
+            rev_short=sha1, text=subject,
+            )
+        yield '\n'
+
+    def generate_update_summary(self, push):
+        """Called for the change of a pre-existing branch."""
+
+        return iter([])
+
+    def generate_delete_summary(self, push):
+        """Called for the deletion of any type of reference."""
+
+        (sha1, subject) = self.old.get_summary()
+        yield self.expand(
+            BRIEF_SUMMARY_TEMPLATE, action='was',
+            rev_short=sha1, text=subject,
+            )
+        yield '\n'
+
+    def get_specific_fromaddr(self):
+        return self.environment.from_refchange
+
+
+class BranchChange(ReferenceChange):
+    refname_type = 'branch'
+
+    def __init__(self, environment, refname, short_refname, old, new, rev):
+        ReferenceChange.__init__(
+            self, environment,
+            refname=refname, short_refname=short_refname,
+            old=old, new=new, rev=rev,
+            )
+        self.recipients = environment.get_refchange_recipients(self)
+        self._single_revision = None
+
+    def send_single_combined_email(self, known_added_sha1s):
+        if not self.environment.combine_when_single_commit:
+            return None
+
+        # In the sadly-all-too-frequent usecase of people pushing only
+        # one of their commits at a time to a repository, users feel
+        # the reference change summary emails are noise rather than
+        # important signal.  This is because, in this particular
+        # usecase, there is a reference change summary email for each
+        # new commit, and all these summaries do is point out that
+        # there is one new commit (which can readily be inferred by
+        # the existence of the individual revision email that is also
+        # sent).  In such cases, our users prefer there to be a combined
+        # reference change summary/new revision email.
+        #
+        # So, if the change is an update and it doesn't discard any
+        # commits, and it adds exactly one non-merge commit (gerrit
+        # forces a workflow where every commit is individually merged
+        # and the git-multimail hook fired off for just this one
+        # change), then we send a combined refchange/revision email.
+        try:
+            # If this change is a reference update that doesn't discard
+            # any commits...
+            if self.change_type != 'update':
+                return None
+
+            if read_git_lines(
+                    ['merge-base', self.old.sha1, self.new.sha1]
+                    ) != [self.old.sha1]:
+                return None
+
+            # Check if this update introduced exactly one non-merge
+            # commit:
+
+            def split_line(line):
+                """Split line into (sha1, [parent,...])."""
+
+                words = line.split()
+                return (words[0], words[1:])
+
+            # Get the new commits introduced by the push as a list of
+            # (sha1, [parent,...])
+            new_commits = [
+                split_line(line)
+                for line in read_git_lines(
+                    [
+                        'log', '-3', '--format=%H %P',
+                        '%s..%s' % (self.old.sha1, self.new.sha1),
+                        ]
+                    )
+                ]
+
+            if not new_commits:
+                return None
+
+            # If the newest commit is a merge, save it for a later check
+            # but otherwise ignore it
+            merge = None
+            tot = len(new_commits)
+            if len(new_commits[0][1]) > 1:
+                merge = new_commits[0][0]
+                del new_commits[0]
+
+            # Our primary check: we can't combine if more than one commit
+            # is introduced.  We also currently only combine if the new
+            # commit is a non-merge commit, though it may make sense to
+            # combine if it is a merge as well.
+            if not (
+                    len(new_commits) == 1 and
+                    len(new_commits[0][1]) == 1 and
+                    new_commits[0][0] in known_added_sha1s
+                    ):
+                return None
+
+            # We do not want to combine revision and refchange emails if
+            # those go to separate locations.
+            rev = Revision(self, GitObject(new_commits[0][0]), 1, tot)
+            if rev.recipients != self.recipients:
+                return None
+
+            # We ignored the newest commit if it was just a merge of the one
+            # commit being introduced.  But we don't want to ignore that
+            # merge commit it it involved conflict resolutions.  Check that.
+            if merge and merge != read_git_output(['diff-tree', '--cc', merge]):
+                return None
+
+            # We can combine the refchange and one new revision emails
+            # into one.  Return the Revision that a combined email should
+            # be sent about.
+            return rev
+        except CommandError:
+            # Cannot determine number of commits in old..new or new..old;
+            # don't combine reference/revision emails:
+            return None
+
+    def generate_combined_email(self, push, revision, body_filter=None, extra_header_values={}):
+        values = revision.get_values()
+        if extra_header_values:
+            values.update(extra_header_values)
+        if 'subject' not in extra_header_values:
+            values['subject'] = self.expand(COMBINED_REFCHANGE_REVISION_SUBJECT_TEMPLATE, **values)
+
+        self._single_revision = revision
+        self._contains_diff()
+        self.header_template = COMBINED_HEADER_TEMPLATE
+        self.intro_template = COMBINED_INTRO_TEMPLATE
+        self.footer_template = COMBINED_FOOTER_TEMPLATE
+
+        def revision_gen_link(base_url):
+            # revision is used only to generate the body, and
+            # _content_type is set while generating headers. Get it
+            # from the BranchChange object.
+            revision._content_type = self._content_type
+            return revision.generate_browse_link(base_url)
+        self.generate_browse_link = revision_gen_link
+        for line in self.generate_email(push, body_filter, values):
+            yield line
+
+    def generate_email_body(self, push):
+        '''Call the appropriate body generation routine.
+
+        If this is a combined refchange/revision email, the special logic
+        for handling this combined email comes from this function.  For
+        other cases, we just use the normal handling.'''
+
+        # If self._single_revision isn't set; don't override
+        if not self._single_revision:
+            for line in super(BranchChange, self).generate_email_body(push):
+                yield line
+            return
+
+        # This is a combined refchange/revision email; we first provide
+        # some info from the refchange portion, and then call the revision
+        # generate_email_body function to handle the revision portion.
+        adds = list(generate_summaries(
+            '--topo-order', '--reverse', '%s..%s'
+            % (self.old.commit_sha1, self.new.commit_sha1,)
+            ))
+
+        yield self.expand("The following commit(s) were added to %(refname)s by this push:\n")
+        for (sha1, subject) in adds:
+            yield self.expand(
+                BRIEF_SUMMARY_TEMPLATE, action='new',
+                rev_short=sha1, text=subject,
+                )
+
+        yield self._single_revision.rev.short + " is described below\n"
+        yield '\n'
+
+        for line in self._single_revision.generate_email_body(push):
+            yield line
+
+
+class AnnotatedTagChange(ReferenceChange):
+    refname_type = 'annotated tag'
+
+    def __init__(self, environment, refname, short_refname, old, new, rev):
+        ReferenceChange.__init__(
+            self, environment,
+            refname=refname, short_refname=short_refname,
+            old=old, new=new, rev=rev,
+            )
+        self.recipients = environment.get_announce_recipients(self)
+        self.show_shortlog = environment.announce_show_shortlog
+
+    ANNOTATED_TAG_FORMAT = (
+        '%(*objectname)\n'
+        '%(*objecttype)\n'
+        '%(taggername)\n'
+        '%(taggerdate)'
+        )
+
+    def describe_tag(self, push):
+        """Describe the new value of an annotated tag."""
+
+        # Use git for-each-ref to pull out the individual fields from
+        # the tag
+        [tagobject, tagtype, tagger, tagged] = read_git_lines(
+            ['for-each-ref', '--format=%s' % (self.ANNOTATED_TAG_FORMAT,), self.refname],
+            )
+
+        yield self.expand(
+            BRIEF_SUMMARY_TEMPLATE, action='tagging',
+            rev_short=tagobject, text='(%s)' % (tagtype,),
+            )
+        if tagtype == 'commit':
+            # If the tagged object is a commit, then we assume this is a
+            # release, and so we calculate which tag this tag is
+            # replacing
+            try:
+                prevtag = read_git_output(['describe', '--abbrev=0', '%s^' % (self.new,)])
+            except CommandError:
+                prevtag = None
+            if prevtag:
+                yield ' replaces %s\n' % (prevtag,)
+        else:
+            prevtag = None
+            yield '  length %s bytes\n' % (read_git_output(['cat-file', '-s', tagobject]),)
+
+        yield '      by %s\n' % (tagger,)
+        yield '      on %s\n' % (tagged,)
+        yield '\n'
+
+        # Show the content of the tag message; this might contain a
+        # change log or release notes so is worth displaying.
+        yield LOGBEGIN
+        contents = list(read_git_lines(['cat-file', 'tag', self.new.sha1], keepends=True))
+        contents = contents[contents.index('\n') + 1:]
+        if contents and contents[-1][-1:] != '\n':
+            contents.append('\n')
+        for line in contents:
+            yield line
+
+        if self.show_shortlog and tagtype == 'commit':
+            # Only commit tags make sense to have rev-list operations
+            # performed on them
+            yield '\n'
+            if prevtag:
+                # Show changes since the previous release
+                revlist = read_git_output(
+                    ['rev-list', '--pretty=short', '%s..%s' % (prevtag, self.new,)],
+                    keepends=True,
+                    )
+            else:
+                # No previous tag, show all the changes since time
+                # began
+                revlist = read_git_output(
+                    ['rev-list', '--pretty=short', '%s' % (self.new,)],
+                    keepends=True,
+                    )
+            for line in read_git_lines(['shortlog'], input=revlist, keepends=True):
+                yield line
+
+        yield LOGEND
+        yield '\n'
+
+    def generate_create_summary(self, push):
+        """Called for the creation of an annotated tag."""
+
+        for line in self.expand_lines(TAG_CREATED_TEMPLATE):
+            yield line
+
+        for line in self.describe_tag(push):
+            yield line
+
+    def generate_update_summary(self, push):
+        """Called for the update of an annotated tag.
+
+        This is probably a rare event and may not even be allowed."""
+
+        for line in self.expand_lines(TAG_UPDATED_TEMPLATE):
+            yield line
+
+        for line in self.describe_tag(push):
+            yield line
+
+    def generate_delete_summary(self, push):
+        """Called when a non-annotated reference is updated."""
+
+        for line in self.expand_lines(TAG_DELETED_TEMPLATE):
+            yield line
+
+        yield self.expand('   tag was  %(oldrev_short)s\n')
+        yield '\n'
+
+
+class NonAnnotatedTagChange(ReferenceChange):
+    refname_type = 'tag'
+
+    def __init__(self, environment, refname, short_refname, old, new, rev):
+        ReferenceChange.__init__(
+            self, environment,
+            refname=refname, short_refname=short_refname,
+            old=old, new=new, rev=rev,
+            )
+        self.recipients = environment.get_refchange_recipients(self)
+
+    def generate_create_summary(self, push):
+        """Called for the creation of an annotated tag."""
+
+        for line in self.expand_lines(TAG_CREATED_TEMPLATE):
+            yield line
+
+    def generate_update_summary(self, push):
+        """Called when a non-annotated reference is updated."""
+
+        for line in self.expand_lines(TAG_UPDATED_TEMPLATE):
+            yield line
+
+    def generate_delete_summary(self, push):
+        """Called when a non-annotated reference is updated."""
+
+        for line in self.expand_lines(TAG_DELETED_TEMPLATE):
+            yield line
+
+        for line in ReferenceChange.generate_delete_summary(self, push):
+            yield line
+
+
+class OtherReferenceChange(ReferenceChange):
+    refname_type = 'reference'
+
+    def __init__(self, environment, refname, short_refname, old, new, rev):
+        # We use the full refname as short_refname, because otherwise
+        # the full name of the reference would not be obvious from the
+        # text of the email.
+        ReferenceChange.__init__(
+            self, environment,
+            refname=refname, short_refname=refname,
+            old=old, new=new, rev=rev,
+            )
+        self.recipients = environment.get_refchange_recipients(self)
+
+
+class Mailer(object):
+    """An object that can send emails."""
+
+    def __init__(self, environment):
+        self.environment = environment
+
+    def close(self):
+        pass
+
+    def send(self, lines, to_addrs):
+        """Send an email consisting of lines.
+
+        lines must be an iterable over the lines constituting the
+        header and body of the email.  to_addrs is a list of recipient
+        addresses (can be needed even if lines already contains a
+        "To:" field).  It can be either a string (comma-separated list
+        of email addresses) or a Python list of individual email
+        addresses.
+
+        """
+
+        raise NotImplementedError()
+
+
+class SendMailer(Mailer):
+    """Send emails using 'sendmail -oi -t'."""
+
+    SENDMAIL_CANDIDATES = [
+        '/usr/sbin/sendmail',
+        '/usr/lib/sendmail',
+        ]
+
+    @staticmethod
+    def find_sendmail():
+        for path in SendMailer.SENDMAIL_CANDIDATES:
+            if os.access(path, os.X_OK):
+                return path
+        else:
+            raise ConfigurationException(
+                'No sendmail executable found.  '
+                'Try setting multimailhook.sendmailCommand.'
+                )
+
+    def __init__(self, environment, command=None, envelopesender=None):
+        """Construct a SendMailer instance.
+
+        command should be the command and arguments used to invoke
+        sendmail, as a list of strings.  If an envelopesender is
+        provided, it will also be passed to the command, via '-f
+        envelopesender'."""
+        super(SendMailer, self).__init__(environment)
+        if command:
+            self.command = command[:]
+        else:
+            self.command = [self.find_sendmail(), '-oi', '-t']
+
+        if envelopesender:
+            self.command.extend(['-f', envelopesender])
+
+    def send(self, lines, to_addrs):
+        try:
+            p = subprocess.Popen(self.command, stdin=subprocess.PIPE)
+        except OSError:
+            self.environment.get_logger().error(
+                '*** Cannot execute command: %s\n' % ' '.join(self.command) +
+                '*** %s\n' % sys.exc_info()[1] +
+                '*** Try setting multimailhook.mailer to "smtp"\n' +
+                '*** to send emails without using the sendmail command.\n'
+                )
+            sys.exit(1)
+        try:
+            lines = (str_to_bytes(line) for line in lines)
+            p.stdin.writelines(lines)
+        except Exception:
+            self.environment.get_logger().error(
+                '*** Error while generating commit email\n'
+                '***  - mail sending aborted.\n'
+                )
+            if hasattr(p, 'terminate'):
+                # subprocess.terminate() is not available in Python 2.4
+                p.terminate()
+            else:
+                import signal
+                os.kill(p.pid, signal.SIGTERM)
+            raise
+        else:
+            p.stdin.close()
+            retcode = p.wait()
+            if retcode:
+                raise CommandError(self.command, retcode)
+
+
+class SMTPMailer(Mailer):
+    """Send emails using Python's smtplib."""
+
+    def __init__(self, environment,
+                 envelopesender, smtpserver,
+                 smtpservertimeout=10.0, smtpserverdebuglevel=0,
+                 smtpencryption='none',
+                 smtpuser='', smtppass='',
+                 smtpcacerts=''
+                 ):
+        super(SMTPMailer, self).__init__(environment)
+        if not envelopesender:
+            self.environment.get_logger().error(
+                'fatal: git_multimail: cannot use SMTPMailer without a sender address.\n'
+                'please set either multimailhook.envelopeSender or user.email\n'
+                )
+            sys.exit(1)
+        if smtpencryption == 'ssl' and not (smtpuser and smtppass):
+            raise ConfigurationException(
+                'Cannot use SMTPMailer with security option ssl '
+                'without options username and password.'
+                )
+        self.envelopesender = envelopesender
+        self.smtpserver = smtpserver
+        self.smtpservertimeout = smtpservertimeout
+        self.smtpserverdebuglevel = smtpserverdebuglevel
+        self.security = smtpencryption
+        self.username = smtpuser
+        self.password = smtppass
+        self.smtpcacerts = smtpcacerts
+        self.loggedin = False
+        try:
+            def call(klass, server, timeout):
+                try:
+                    return klass(server, timeout=timeout)
+                except TypeError:
+                    # Old Python versions do not have timeout= argument.
+                    return klass(server)
+            if self.security == 'none':
+                self.smtp = call(smtplib.SMTP, self.smtpserver, timeout=self.smtpservertimeout)
+            elif self.security == 'ssl':
+                if self.smtpcacerts:
+                    raise smtplib.SMTPException(
+                        "Checking certificate is not supported for ssl, prefer starttls"
+                        )
+                self.smtp = call(smtplib.SMTP_SSL, self.smtpserver, timeout=self.smtpservertimeout)
+            elif self.security == 'tls':
+                if 'ssl' not in sys.modules:
+                    self.environment.get_logger().error(
+                        '*** Your Python version does not have the ssl library installed\n'
+                        '*** smtpEncryption=tls is not available.\n'
+                        '*** Either upgrade Python to 2.6 or later\n'
+                        '    or use git_multimail.py version 1.2.\n')
+                if ':' not in self.smtpserver:
+                    self.smtpserver += ':587'  # default port for TLS
+                self.smtp = call(smtplib.SMTP, self.smtpserver, timeout=self.smtpservertimeout)
+                # start: ehlo + starttls
+                # equivalent to
+                #     self.smtp.ehlo()
+                #     self.smtp.starttls()
+                # with acces to the ssl layer
+                self.smtp.ehlo()
+                if not self.smtp.has_extn("starttls"):
+                    raise smtplib.SMTPException("STARTTLS extension not supported by server")
+                resp, reply = self.smtp.docmd("STARTTLS")
+                if resp != 220:
+                    raise smtplib.SMTPException("Wrong answer to the STARTTLS command")
+                if self.smtpcacerts:
+                    self.smtp.sock = ssl.wrap_socket(
+                        self.smtp.sock,
+                        ca_certs=self.smtpcacerts,
+                        cert_reqs=ssl.CERT_REQUIRED
+                        )
+                else:
+                    self.smtp.sock = ssl.wrap_socket(
+                        self.smtp.sock,
+                        cert_reqs=ssl.CERT_NONE
+                        )
+                    self.environment.get_logger().error(
+                        '*** Warning, the server certificat is not verified (smtp) ***\n'
+                        '***          set the option smtpCACerts                   ***\n'
+                        )
+                if not hasattr(self.smtp.sock, "read"):
+                    # using httplib.FakeSocket with Python 2.5.x or earlier
+                    self.smtp.sock.read = self.smtp.sock.recv
+                self.smtp.file = smtplib.SSLFakeFile(self.smtp.sock)
+                self.smtp.helo_resp = None
+                self.smtp.ehlo_resp = None
+                self.smtp.esmtp_features = {}
+                self.smtp.does_esmtp = 0
+                # end:   ehlo + starttls
+                self.smtp.ehlo()
+            else:
+                sys.stdout.write('*** Error: Control reached an invalid option. ***')
+                sys.exit(1)
+            if self.smtpserverdebuglevel > 0:
+                sys.stdout.write(
+                    "*** Setting debug on for SMTP server connection (%s) ***\n"
+                    % self.smtpserverdebuglevel)
+                self.smtp.set_debuglevel(self.smtpserverdebuglevel)
+        except Exception:
+            self.environment.get_logger().error(
+                '*** Error establishing SMTP connection to %s ***\n'
+                '*** %s\n'
+                % (self.smtpserver, sys.exc_info()[1]))
+            sys.exit(1)
+
+    def close(self):
+        if hasattr(self, 'smtp'):
+            self.smtp.quit()
+            del self.smtp
+
+    def __del__(self):
+        self.close()
+
+    def send(self, lines, to_addrs):
+        try:
+            if self.username or self.password:
+                if not self.loggedin:
+                    self.smtp.login(self.username, self.password)
+                    self.loggedin = True
+            msg = ''.join(lines)
+            # turn comma-separated list into Python list if needed.
+            if is_string(to_addrs):
+                to_addrs = [email for (name, email) in getaddresses([to_addrs])]
+            self.smtp.sendmail(self.envelopesender, to_addrs, msg)
+        except socket.timeout:
+            self.environment.get_logger().error(
+                '*** Error sending email ***\n'
+                '*** SMTP server timed out (timeout is %s)\n'
+                % self.smtpservertimeout)
+        except smtplib.SMTPResponseException:
+            err = sys.exc_info()[1]
+            self.environment.get_logger().error(
+                '*** Error sending email ***\n'
+                '*** Error %d: %s\n'
+                % (err.smtp_code, bytes_to_str(err.smtp_error)))
+            try:
+                smtp = self.smtp
+                # delete the field before quit() so that in case of
+                # error, self.smtp is deleted anyway.
+                del self.smtp
+                smtp.quit()
+            except:
+                self.environment.get_logger().error(
+                    '*** Error closing the SMTP connection ***\n'
+                    '*** Exiting anyway ... ***\n'
+                    '*** %s\n' % sys.exc_info()[1])
+            sys.exit(1)
+
+
+class OutputMailer(Mailer):
+    """Write emails to an output stream, bracketed by lines of '=' characters.
+
+    This is intended for debugging purposes."""
+
+    SEPARATOR = '=' * 75 + '\n'
+
+    def __init__(self, f, environment=None):
+        super(OutputMailer, self).__init__(environment=environment)
+        self.f = f
+
+    def send(self, lines, to_addrs):
+        write_str(self.f, self.SEPARATOR)
+        for line in lines:
+            write_str(self.f, line)
+        write_str(self.f, self.SEPARATOR)
+
+
+def get_git_dir():
+    """Determine GIT_DIR.
+
+    Determine GIT_DIR either from the GIT_DIR environment variable or
+    from the working directory, using Git's usual rules."""
+
+    try:
+        return read_git_output(['rev-parse', '--git-dir'])
+    except CommandError:
+        sys.stderr.write('fatal: git_multimail: not in a git directory\n')
+        sys.exit(1)
+
+
+class Environment(object):
+    """Describes the environment in which the push is occurring.
+
+    An Environment object encapsulates information about the local
+    environment.  For example, it knows how to determine:
+
+    * the name of the repository to which the push occurred
+
+    * what user did the push
+
+    * what users want to be informed about various types of changes.
+
+    An Environment object is expected to have the following methods:
+
+        get_repo_shortname()
+
+            Return a short name for the repository, for display
+            purposes.
+
+        get_repo_path()
+
+            Return the absolute path to the Git repository.
+
+        get_emailprefix()
+
+            Return a string that will be prefixed to every email's
+            subject.
+
+        get_pusher()
+
+            Return the username of the person who pushed the changes.
+            This value is used in the email body to indicate who
+            pushed the change.
+
+        get_pusher_email() (may return None)
+
+            Return the email address of the person who pushed the
+            changes.  The value should be a single RFC 2822 email
+            address as a string; e.g., "Joe User "
+            if available, otherwise "user@example.com".  If set, the
+            value is used as the Reply-To address for refchange
+            emails.  If it is impossible to determine the pusher's
+            email, this attribute should be set to None (in which case
+            no Reply-To header will be output).
+
+        get_sender()
+
+            Return the address to be used as the 'From' email address
+            in the email envelope.
+
+        get_fromaddr(change=None)
+
+            Return the 'From' email address used in the email 'From:'
+            headers.  If the change is known when this function is
+            called, it is passed in as the 'change' parameter.  (May
+            be a full RFC 2822 email address like 'Joe User
+            '.)
+
+        get_administrator()
+
+            Return the name and/or email of the repository
+            administrator.  This value is used in the footer as the
+            person to whom requests to be removed from the
+            notification list should be sent.  Ideally, it should
+            include a valid email address.
+
+        get_reply_to_refchange()
+        get_reply_to_commit()
+
+            Return the address to use in the email "Reply-To" header,
+            as a string.  These can be an RFC 2822 email address, or
+            None to omit the "Reply-To" header.
+            get_reply_to_refchange() is used for refchange emails;
+            get_reply_to_commit() is used for individual commit
+            emails.
+
+        get_ref_filter_regex()
+
+            Return a tuple -- a compiled regex, and a boolean indicating
+            whether the regex picks refs to include (if False, the regex
+            matches on refs to exclude).
+
+        get_default_ref_ignore_regex()
+
+            Return a regex that should be ignored for both what emails
+            to send and when computing what commits are considered new
+            to the repository.  Default is "^refs/notes/".
+
+        get_max_subject_length()
+
+            Return an int giving the maximal length for the subject
+            (git log --oneline).
+
+    They should also define the following attributes:
+
+        announce_show_shortlog (bool)
+
+            True iff announce emails should include a shortlog.
+
+        commit_email_format (string)
+
+            If "html", generate commit emails in HTML instead of plain text
+            used by default.
+
+        html_in_intro (bool)
+        html_in_footer (bool)
+
+            When generating HTML emails, the introduction (respectively,
+            the footer) will be HTML-escaped iff html_in_intro (respectively,
+            the footer) is true. When false, only the values used to expand
+            the template are escaped.
+
+        refchange_showgraph (bool)
+
+            True iff refchanges emails should include a detailed graph.
+
+        refchange_showlog (bool)
+
+            True iff refchanges emails should include a detailed log.
+
+        diffopts (list of strings)
+
+            The options that should be passed to 'git diff' for the
+            summary email.  The value should be a list of strings
+            representing words to be passed to the command.
+
+        graphopts (list of strings)
+
+            Analogous to diffopts, but contains options passed to
+            'git log --graph' when generating the detailed graph for
+            a set of commits (see refchange_showgraph)
+
+        logopts (list of strings)
+
+            Analogous to diffopts, but contains options passed to
+            'git log' when generating the detailed log for a set of
+            commits (see refchange_showlog)
+
+        commitlogopts (list of strings)
+
+            The options that should be passed to 'git log' for each
+            commit mail.  The value should be a list of strings
+            representing words to be passed to the command.
+
+        date_substitute (string)
+
+            String to be used in substitution for 'Date:' at start of
+            line in the output of 'git log'.
+
+        quiet (bool)
+            On success do not write to stderr
+
+        stdout (bool)
+            Write email to stdout rather than emailing. Useful for debugging
+
+        combine_when_single_commit (bool)
+
+            True if a combined email should be produced when a single
+            new commit is pushed to a branch, False otherwise.
+
+        from_refchange, from_commit (strings)
+
+            Addresses to use for the From: field for refchange emails
+            and commit emails respectively.  Set from
+            multimailhook.fromRefchange and multimailhook.fromCommit
+            by ConfigEnvironmentMixin.
+
+        log_file, error_log_file, debug_log_file (string)
+
+            Name of a file to which logs should be sent.
+
+        verbose (int)
+
+            How verbose the system should be.
+            - 0 (default): show info, errors, ...
+            - 1 : show basic debug info
+    """
+
+    REPO_NAME_RE = re.compile(r'^(?P.+?)(?:\.git)$')
+
+    def __init__(self, osenv=None):
+        self.osenv = osenv or os.environ
+        self.announce_show_shortlog = False
+        self.commit_email_format = "text"
+        self.html_in_intro = False
+        self.html_in_footer = False
+        self.commitBrowseURL = None
+        self.maxcommitemails = 500
+        self.excludemergerevisions = False
+        self.diffopts = ['--stat', '--summary', '--find-copies-harder']
+        self.graphopts = ['--oneline', '--decorate']
+        self.logopts = []
+        self.refchange_showgraph = False
+        self.refchange_showlog = False
+        self.commitlogopts = ['-C', '--stat', '-p', '--cc']
+        self.date_substitute = 'AuthorDate: '
+        self.quiet = False
+        self.stdout = False
+        self.combine_when_single_commit = True
+        self.logger = None
+
+        self.COMPUTED_KEYS = [
+            'administrator',
+            'charset',
+            'emailprefix',
+            'pusher',
+            'pusher_email',
+            'repo_path',
+            'repo_shortname',
+            'sender',
+            ]
+
+        self._values = None
+
+    def get_logger(self):
+        """Get (possibly creates) the logger associated to this environment."""
+        if self.logger is None:
+            self.logger = Logger(self)
+        return self.logger
+
+    def get_repo_shortname(self):
+        """Use the last part of the repo path, with ".git" stripped off if present."""
+
+        basename = os.path.basename(os.path.abspath(self.get_repo_path()))
+        m = self.REPO_NAME_RE.match(basename)
+        if m:
+            return m.group('name')
+        else:
+            return basename
+
+    def get_pusher(self):
+        raise NotImplementedError()
+
+    def get_pusher_email(self):
+        return None
+
+    def get_fromaddr(self, change=None):
+        config = Config('user')
+        fromname = config.get('name', default='')
+        fromemail = config.get('email', default='')
+        if fromemail:
+            return formataddr([fromname, fromemail])
+        return self.get_sender()
+
+    def get_administrator(self):
+        return 'the administrator of this repository'
+
+    def get_emailprefix(self):
+        return ''
+
+    def get_repo_path(self):
+        if read_git_output(['rev-parse', '--is-bare-repository']) == 'true':
+            path = get_git_dir()
+        else:
+            path = read_git_output(['rev-parse', '--show-toplevel'])
+        return os.path.abspath(path)
+
+    def get_charset(self):
+        return CHARSET
+
+    def get_values(self):
+        """Return a dictionary {keyword: expansion} for this Environment.
+
+        This method is called by Change._compute_values().  The keys
+        in the returned dictionary are available to be used in any of
+        the templates.  The dictionary is created by calling
+        self.get_NAME() for each of the attributes named in
+        COMPUTED_KEYS and recording those that do not return None.
+        The return value is always a new dictionary."""
+
+        if self._values is None:
+            values = {'': ''}  # %()s expands to the empty string.
+
+            for key in self.COMPUTED_KEYS:
+                value = getattr(self, 'get_%s' % (key,))()
+                if value is not None:
+                    values[key] = value
+
+            self._values = values
+
+        return self._values.copy()
+
+    def get_refchange_recipients(self, refchange):
+        """Return the recipients for notifications about refchange.
+
+        Return the list of email addresses to which notifications
+        about the specified ReferenceChange should be sent."""
+
+        raise NotImplementedError()
+
+    def get_announce_recipients(self, annotated_tag_change):
+        """Return the recipients for notifications about annotated_tag_change.
+
+        Return the list of email addresses to which notifications
+        about the specified AnnotatedTagChange should be sent."""
+
+        raise NotImplementedError()
+
+    def get_reply_to_refchange(self, refchange):
+        return self.get_pusher_email()
+
+    def get_revision_recipients(self, revision):
+        """Return the recipients for messages about revision.
+
+        Return the list of email addresses to which notifications
+        about the specified Revision should be sent.  This method
+        could be overridden, for example, to take into account the
+        contents of the revision when deciding whom to notify about
+        it.  For example, there could be a scheme for users to express
+        interest in particular files or subdirectories, and only
+        receive notification emails for revisions that affecting those
+        files."""
+
+        raise NotImplementedError()
+
+    def get_reply_to_commit(self, revision):
+        return revision.author
+
+    def get_default_ref_ignore_regex(self):
+        # The commit messages of git notes are essentially meaningless
+        # and "filenames" in git notes commits are an implementational
+        # detail that might surprise users at first.  As such, we
+        # would need a completely different method for handling emails
+        # of git notes in order for them to be of benefit for users,
+        # which we simply do not have right now.
+        return "^refs/notes/"
+
+    def get_max_subject_length(self):
+        """Return the maximal subject line (git log --oneline) length.
+        Longer subject lines will be truncated."""
+        raise NotImplementedError()
+
+    def filter_body(self, lines):
+        """Filter the lines intended for an email body.
+
+        lines is an iterable over the lines that would go into the
+        email body.  Filter it (e.g., limit the number of lines, the
+        line length, character set, etc.), returning another iterable.
+        See FilterLinesEnvironmentMixin and MaxlinesEnvironmentMixin
+        for classes implementing this functionality."""
+
+        return lines
+
+    def log_msg(self, msg):
+        """Write the string msg on a log file or on stderr.
+
+        Sends the text to stderr by default, override to change the behavior."""
+        self.get_logger().info(msg)
+
+    def log_warning(self, msg):
+        """Write the string msg on a log file or on stderr.
+
+        Sends the text to stderr by default, override to change the behavior."""
+        self.get_logger().warning(msg)
+
+    def log_error(self, msg):
+        """Write the string msg on a log file or on stderr.
+
+        Sends the text to stderr by default, override to change the behavior."""
+        self.get_logger().error(msg)
+
+    def check(self):
+        pass
+
+
+class ConfigEnvironmentMixin(Environment):
+    """A mixin that sets self.config to its constructor's config argument.
+
+    This class's constructor consumes the "config" argument.
+
+    Mixins that need to inspect the config should inherit from this
+    class (1) to make sure that "config" is still in the constructor
+    arguments with its own constructor runs and/or (2) to be sure that
+    self.config is set after construction."""
+
+    def __init__(self, config, **kw):
+        super(ConfigEnvironmentMixin, self).__init__(**kw)
+        self.config = config
+
+
+class ConfigOptionsEnvironmentMixin(ConfigEnvironmentMixin):
+    """An Environment that reads most of its information from "git config"."""
+
+    @staticmethod
+    def forbid_field_values(name, value, forbidden):
+        for forbidden_val in forbidden:
+            if value is not None and value.lower() == forbidden:
+                raise ConfigurationException(
+                    '"%s" is not an allowed setting for %s' % (value, name)
+                    )
+
+    def __init__(self, config, **kw):
+        super(ConfigOptionsEnvironmentMixin, self).__init__(
+            config=config, **kw
+            )
+
+        for var, cfg in (
+                ('announce_show_shortlog', 'announceshortlog'),
+                ('refchange_showgraph', 'refchangeShowGraph'),
+                ('refchange_showlog', 'refchangeshowlog'),
+                ('quiet', 'quiet'),
+                ('stdout', 'stdout'),
+                ):
+            val = config.get_bool(cfg)
+            if val is not None:
+                setattr(self, var, val)
+
+        commit_email_format = config.get('commitEmailFormat')
+        if commit_email_format is not None:
+            if commit_email_format != "html" and commit_email_format != "text":
+                self.log_warning(
+                    '*** Unknown value for multimailhook.commitEmailFormat: %s\n' %
+                    commit_email_format +
+                    '*** Expected either "text" or "html".  Ignoring.\n'
+                    )
+            else:
+                self.commit_email_format = commit_email_format
+
+        html_in_intro = config.get_bool('htmlInIntro')
+        if html_in_intro is not None:
+            self.html_in_intro = html_in_intro
+
+        html_in_footer = config.get_bool('htmlInFooter')
+        if html_in_footer is not None:
+            self.html_in_footer = html_in_footer
+
+        self.commitBrowseURL = config.get('commitBrowseURL')
+
+        self.excludemergerevisions = config.get('excludeMergeRevisions')
+
+        maxcommitemails = config.get('maxcommitemails')
+        if maxcommitemails is not None:
+            try:
+                self.maxcommitemails = int(maxcommitemails)
+            except ValueError:
+                self.log_warning(
+                    '*** Malformed value for multimailhook.maxCommitEmails: %s\n'
+                    % maxcommitemails +
+                    '*** Expected a number.  Ignoring.\n'
+                    )
+
+        diffopts = config.get('diffopts')
+        if diffopts is not None:
+            self.diffopts = shlex.split(diffopts)
+
+        graphopts = config.get('graphOpts')
+        if graphopts is not None:
+            self.graphopts = shlex.split(graphopts)
+
+        logopts = config.get('logopts')
+        if logopts is not None:
+            self.logopts = shlex.split(logopts)
+
+        commitlogopts = config.get('commitlogopts')
+        if commitlogopts is not None:
+            self.commitlogopts = shlex.split(commitlogopts)
+
+        date_substitute = config.get('dateSubstitute')
+        if date_substitute == 'none':
+            self.date_substitute = None
+        elif date_substitute is not None:
+            self.date_substitute = date_substitute
+
+        reply_to = config.get('replyTo')
+        self.__reply_to_refchange = config.get('replyToRefchange', default=reply_to)
+        self.forbid_field_values('replyToRefchange',
+                                 self.__reply_to_refchange,
+                                 ['author'])
+        self.__reply_to_commit = config.get('replyToCommit', default=reply_to)
+
+        self.from_refchange = config.get('fromRefchange')
+        self.forbid_field_values('fromRefchange',
+                                 self.from_refchange,
+                                 ['author', 'none'])
+        self.from_commit = config.get('fromCommit')
+        self.forbid_field_values('fromCommit',
+                                 self.from_commit,
+                                 ['none'])
+
+        combine = config.get_bool('combineWhenSingleCommit')
+        if combine is not None:
+            self.combine_when_single_commit = combine
+
+        self.log_file = config.get('logFile', default=None)
+        self.error_log_file = config.get('errorLogFile', default=None)
+        self.debug_log_file = config.get('debugLogFile', default=None)
+        if config.get_bool('Verbose', default=False):
+            self.verbose = 1
+        else:
+            self.verbose = 0
+
+    def get_administrator(self):
+        return (
+            self.config.get('administrator') or
+            self.get_sender() or
+            super(ConfigOptionsEnvironmentMixin, self).get_administrator()
+            )
+
+    def get_repo_shortname(self):
+        return (
+            self.config.get('reponame') or
+            super(ConfigOptionsEnvironmentMixin, self).get_repo_shortname()
+            )
+
+    def get_emailprefix(self):
+        emailprefix = self.config.get('emailprefix')
+        if emailprefix is not None:
+            emailprefix = emailprefix.strip()
+            if emailprefix:
+                emailprefix += ' '
+        else:
+            emailprefix = '[%(repo_shortname)s] '
+        short_name = self.get_repo_shortname()
+        try:
+            return emailprefix % {'repo_shortname': short_name}
+        except:
+            self.get_logger().error(
+                '*** Invalid multimailhook.emailPrefix: %s\n' % emailprefix +
+                '*** %s\n' % sys.exc_info()[1] +
+                "*** Only the '%(repo_shortname)s' placeholder is allowed\n"
+                )
+            raise ConfigurationException(
+                '"%s" is not an allowed setting for emailPrefix' % emailprefix
+                )
+
+    def get_sender(self):
+        return self.config.get('envelopesender')
+
+    def process_addr(self, addr, change):
+        if addr.lower() == 'author':
+            if hasattr(change, 'author'):
+                return change.author
+            else:
+                return None
+        elif addr.lower() == 'pusher':
+            return self.get_pusher_email()
+        elif addr.lower() == 'none':
+            return None
+        else:
+            return addr
+
+    def get_fromaddr(self, change=None):
+        fromaddr = self.config.get('from')
+        if change:
+            specific_fromaddr = change.get_specific_fromaddr()
+            if specific_fromaddr:
+                fromaddr = specific_fromaddr
+        if fromaddr:
+            fromaddr = self.process_addr(fromaddr, change)
+        if fromaddr:
+            return fromaddr
+        return super(ConfigOptionsEnvironmentMixin, self).get_fromaddr(change)
+
+    def get_reply_to_refchange(self, refchange):
+        if self.__reply_to_refchange is None:
+            return super(ConfigOptionsEnvironmentMixin, self).get_reply_to_refchange(refchange)
+        else:
+            return self.process_addr(self.__reply_to_refchange, refchange)
+
+    def get_reply_to_commit(self, revision):
+        if self.__reply_to_commit is None:
+            return super(ConfigOptionsEnvironmentMixin, self).get_reply_to_commit(revision)
+        else:
+            return self.process_addr(self.__reply_to_commit, revision)
+
+    def get_scancommitforcc(self):
+        return self.config.get('scancommitforcc')
+
+
+class FilterLinesEnvironmentMixin(Environment):
+    """Handle encoding and maximum line length of body lines.
+
+        email_max_line_length (int or None)
+
+            The maximum length of any single line in the email body.
+            Longer lines are truncated at that length with ' [...]'
+            appended.
+
+        strict_utf8 (bool)
+
+            If this field is set to True, then the email body text is
+            expected to be UTF-8.  Any invalid characters are
+            converted to U+FFFD, the Unicode replacement character
+            (encoded as UTF-8, of course).
+
+    """
+
+    def __init__(self, strict_utf8=True,
+                 email_max_line_length=500, max_subject_length=500,
+                 **kw):
+        super(FilterLinesEnvironmentMixin, self).__init__(**kw)
+        self.__strict_utf8 = strict_utf8
+        self.__email_max_line_length = email_max_line_length
+        self.__max_subject_length = max_subject_length
+
+    def filter_body(self, lines):
+        lines = super(FilterLinesEnvironmentMixin, self).filter_body(lines)
+        if self.__strict_utf8:
+            if not PYTHON3:
+                lines = (line.decode(ENCODING, 'replace') for line in lines)
+            # Limit the line length in Unicode-space to avoid
+            # splitting characters:
+            if self.__email_max_line_length > 0:
+                lines = limit_linelength(lines, self.__email_max_line_length)
+            if not PYTHON3:
+                lines = (line.encode(ENCODING, 'replace') for line in lines)
+        elif self.__email_max_line_length:
+            lines = limit_linelength(lines, self.__email_max_line_length)
+
+        return lines
+
+    def get_max_subject_length(self):
+        return self.__max_subject_length
+
+
+class ConfigFilterLinesEnvironmentMixin(
+        ConfigEnvironmentMixin,
+        FilterLinesEnvironmentMixin,
+        ):
+    """Handle encoding and maximum line length based on config."""
+
+    def __init__(self, config, **kw):
+        strict_utf8 = config.get_bool('emailstrictutf8', default=None)
+        if strict_utf8 is not None:
+            kw['strict_utf8'] = strict_utf8
+
+        email_max_line_length = config.get('emailmaxlinelength')
+        if email_max_line_length is not None:
+            kw['email_max_line_length'] = int(email_max_line_length)
+
+        max_subject_length = config.get('subjectMaxLength', default=email_max_line_length)
+        if max_subject_length is not None:
+            kw['max_subject_length'] = int(max_subject_length)
+
+        super(ConfigFilterLinesEnvironmentMixin, self).__init__(
+            config=config, **kw
+            )
+
+
+class MaxlinesEnvironmentMixin(Environment):
+    """Limit the email body to a specified number of lines."""
+
+    def __init__(self, emailmaxlines, **kw):
+        super(MaxlinesEnvironmentMixin, self).__init__(**kw)
+        self.__emailmaxlines = emailmaxlines
+
+    def filter_body(self, lines):
+        lines = super(MaxlinesEnvironmentMixin, self).filter_body(lines)
+        if self.__emailmaxlines > 0:
+            lines = limit_lines(lines, self.__emailmaxlines)
+        return lines
+
+
+class ConfigMaxlinesEnvironmentMixin(
+        ConfigEnvironmentMixin,
+        MaxlinesEnvironmentMixin,
+        ):
+    """Limit the email body to the number of lines specified in config."""
+
+    def __init__(self, config, **kw):
+        emailmaxlines = int(config.get('emailmaxlines', default='0'))
+        super(ConfigMaxlinesEnvironmentMixin, self).__init__(
+            config=config,
+            emailmaxlines=emailmaxlines,
+            **kw
+            )
+
+
+class FQDNEnvironmentMixin(Environment):
+    """A mixin that sets the host's FQDN to its constructor argument."""
+
+    def __init__(self, fqdn, **kw):
+        super(FQDNEnvironmentMixin, self).__init__(**kw)
+        self.COMPUTED_KEYS += ['fqdn']
+        self.__fqdn = fqdn
+
+    def get_fqdn(self):
+        """Return the fully-qualified domain name for this host.
+
+        Return None if it is unavailable or unwanted."""
+
+        return self.__fqdn
+
+
+class ConfigFQDNEnvironmentMixin(
+        ConfigEnvironmentMixin,
+        FQDNEnvironmentMixin,
+        ):
+    """Read the FQDN from the config."""
+
+    def __init__(self, config, **kw):
+        fqdn = config.get('fqdn')
+        super(ConfigFQDNEnvironmentMixin, self).__init__(
+            config=config,
+            fqdn=fqdn,
+            **kw
+            )
+
+
+class ComputeFQDNEnvironmentMixin(FQDNEnvironmentMixin):
+    """Get the FQDN by calling socket.getfqdn()."""
+
+    def __init__(self, **kw):
+        super(ComputeFQDNEnvironmentMixin, self).__init__(
+            fqdn=socket.getfqdn(),
+            **kw
+            )
+
+
+class PusherDomainEnvironmentMixin(ConfigEnvironmentMixin):
+    """Deduce pusher_email from pusher by appending an emaildomain."""
+
+    def __init__(self, **kw):
+        super(PusherDomainEnvironmentMixin, self).__init__(**kw)
+        self.__emaildomain = self.config.get('emaildomain')
+
+    def get_pusher_email(self):
+        if self.__emaildomain:
+            # Derive the pusher's full email address in the default way:
+            return '%s@%s' % (self.get_pusher(), self.__emaildomain)
+        else:
+            return super(PusherDomainEnvironmentMixin, self).get_pusher_email()
+
+
+class StaticRecipientsEnvironmentMixin(Environment):
+    """Set recipients statically based on constructor parameters."""
+
+    def __init__(
+            self,
+            refchange_recipients, announce_recipients, revision_recipients, scancommitforcc,
+            **kw
+            ):
+        super(StaticRecipientsEnvironmentMixin, self).__init__(**kw)
+
+        # The recipients for various types of notification emails, as
+        # RFC 2822 email addresses separated by commas (or the empty
+        # string if no recipients are configured).  Although there is
+        # a mechanism to choose the recipient lists based on on the
+        # actual *contents* of the change being reported, we only
+        # choose based on the *type* of the change.  Therefore we can
+        # compute them once and for all:
+        self.__refchange_recipients = refchange_recipients
+        self.__announce_recipients = announce_recipients
+        self.__revision_recipients = revision_recipients
+
+    def check(self):
+        if not (self.get_refchange_recipients(None) or
+                self.get_announce_recipients(None) or
+                self.get_revision_recipients(None) or
+                self.get_scancommitforcc()):
+            raise ConfigurationException('No email recipients configured!')
+        super(StaticRecipientsEnvironmentMixin, self).check()
+
+    def get_refchange_recipients(self, refchange):
+        if self.__refchange_recipients is None:
+            return super(StaticRecipientsEnvironmentMixin,
+                         self).get_refchange_recipients(refchange)
+        return self.__refchange_recipients
+
+    def get_announce_recipients(self, annotated_tag_change):
+        if self.__announce_recipients is None:
+            return super(StaticRecipientsEnvironmentMixin,
+                         self).get_refchange_recipients(annotated_tag_change)
+        return self.__announce_recipients
+
+    def get_revision_recipients(self, revision):
+        if self.__revision_recipients is None:
+            return super(StaticRecipientsEnvironmentMixin,
+                         self).get_refchange_recipients(revision)
+        return self.__revision_recipients
+
+
+class CLIRecipientsEnvironmentMixin(Environment):
+    """Mixin storing recipients information coming from the
+    command-line."""
+
+    def __init__(self, cli_recipients=None, **kw):
+        super(CLIRecipientsEnvironmentMixin, self).__init__(**kw)
+        self.__cli_recipients = cli_recipients
+
+    def get_refchange_recipients(self, refchange):
+        if self.__cli_recipients is None:
+            return super(CLIRecipientsEnvironmentMixin,
+                         self).get_refchange_recipients(refchange)
+        return self.__cli_recipients
+
+    def get_announce_recipients(self, annotated_tag_change):
+        if self.__cli_recipients is None:
+            return super(CLIRecipientsEnvironmentMixin,
+                         self).get_announce_recipients(annotated_tag_change)
+        return self.__cli_recipients
+
+    def get_revision_recipients(self, revision):
+        if self.__cli_recipients is None:
+            return super(CLIRecipientsEnvironmentMixin,
+                         self).get_revision_recipients(revision)
+        return self.__cli_recipients
+
+
+class ConfigRecipientsEnvironmentMixin(
+        ConfigEnvironmentMixin,
+        StaticRecipientsEnvironmentMixin
+        ):
+    """Determine recipients statically based on config."""
+
+    def __init__(self, config, **kw):
+        super(ConfigRecipientsEnvironmentMixin, self).__init__(
+            config=config,
+            refchange_recipients=self._get_recipients(
+                config, 'refchangelist', 'mailinglist',
+                ),
+            announce_recipients=self._get_recipients(
+                config, 'announcelist', 'refchangelist', 'mailinglist',
+                ),
+            revision_recipients=self._get_recipients(
+                config, 'commitlist', 'mailinglist',
+                ),
+            scancommitforcc=config.get('scancommitforcc'),
+            **kw
+            )
+
+    def _get_recipients(self, config, *names):
+        """Return the recipients for a particular type of message.
+
+        Return the list of email addresses to which a particular type
+        of notification email should be sent, by looking at the config
+        value for "multimailhook.$name" for each of names.  Use the
+        value from the first name that is configured.  The return
+        value is a (possibly empty) string containing RFC 2822 email
+        addresses separated by commas.  If no configuration could be
+        found, raise a ConfigurationException."""
+
+        for name in names:
+            lines = config.get_all(name)
+            if lines is not None:
+                lines = [line.strip() for line in lines]
+                # Single "none" is a special value equivalen to empty string.
+                if lines == ['none']:
+                    lines = ['']
+                return ', '.join(lines)
+        else:
+            return ''
+
+
+class StaticRefFilterEnvironmentMixin(Environment):
+    """Set branch filter statically based on constructor parameters."""
+
+    def __init__(self, ref_filter_incl_regex, ref_filter_excl_regex,
+                 ref_filter_do_send_regex, ref_filter_dont_send_regex,
+                 **kw):
+        super(StaticRefFilterEnvironmentMixin, self).__init__(**kw)
+
+        if ref_filter_incl_regex and ref_filter_excl_regex:
+            raise ConfigurationException(
+                "Cannot specify both a ref inclusion and exclusion regex.")
+        self.__is_inclusion_filter = bool(ref_filter_incl_regex)
+        default_exclude = self.get_default_ref_ignore_regex()
+        if ref_filter_incl_regex:
+            ref_filter_regex = ref_filter_incl_regex
+        elif ref_filter_excl_regex:
+            ref_filter_regex = ref_filter_excl_regex + '|' + default_exclude
+        else:
+            ref_filter_regex = default_exclude
+        try:
+            self.__compiled_regex = re.compile(ref_filter_regex)
+        except Exception:
+            raise ConfigurationException(
+                'Invalid Ref Filter Regex "%s": %s' % (ref_filter_regex, sys.exc_info()[1]))
+
+        if ref_filter_do_send_regex and ref_filter_dont_send_regex:
+            raise ConfigurationException(
+                "Cannot specify both a ref doSend and dontSend regex.")
+        self.__is_do_send_filter = bool(ref_filter_do_send_regex)
+        if ref_filter_do_send_regex:
+            ref_filter_send_regex = ref_filter_do_send_regex
+        elif ref_filter_dont_send_regex:
+            ref_filter_send_regex = ref_filter_dont_send_regex
+        else:
+            ref_filter_send_regex = '.*'
+            self.__is_do_send_filter = True
+        try:
+            self.__send_compiled_regex = re.compile(ref_filter_send_regex)
+        except Exception:
+            raise ConfigurationException(
+                'Invalid Ref Filter Regex "%s": %s' %
+                (ref_filter_send_regex, sys.exc_info()[1]))
+
+    def get_ref_filter_regex(self, send_filter=False):
+        if send_filter:
+            return self.__send_compiled_regex, self.__is_do_send_filter
+        else:
+            return self.__compiled_regex, self.__is_inclusion_filter
+
+
+class ConfigRefFilterEnvironmentMixin(
+        ConfigEnvironmentMixin,
+        StaticRefFilterEnvironmentMixin
+        ):
+    """Determine branch filtering statically based on config."""
+
+    def _get_regex(self, config, key):
+        """Get a list of whitespace-separated regex. The refFilter* config
+        variables are multivalued (hence the use of get_all), and we
+        allow each entry to be a whitespace-separated list (hence the
+        split on each line). The whole thing is glued into a single regex."""
+        values = config.get_all(key)
+        if values is None:
+            return values
+        items = []
+        for line in values:
+            for i in line.split():
+                items.append(i)
+        if items == []:
+            return None
+        return '|'.join(items)
+
+    def __init__(self, config, **kw):
+        super(ConfigRefFilterEnvironmentMixin, self).__init__(
+            config=config,
+            ref_filter_incl_regex=self._get_regex(config, 'refFilterInclusionRegex'),
+            ref_filter_excl_regex=self._get_regex(config, 'refFilterExclusionRegex'),
+            ref_filter_do_send_regex=self._get_regex(config, 'refFilterDoSendRegex'),
+            ref_filter_dont_send_regex=self._get_regex(config, 'refFilterDontSendRegex'),
+            **kw
+            )
+
+
+class ProjectdescEnvironmentMixin(Environment):
+    """Make a "projectdesc" value available for templates.
+
+    By default, it is set to the first line of $GIT_DIR/description
+    (if that file is present and appears to be set meaningfully)."""
+
+    def __init__(self, **kw):
+        super(ProjectdescEnvironmentMixin, self).__init__(**kw)
+        self.COMPUTED_KEYS += ['projectdesc']
+
+    def get_projectdesc(self):
+        """Return a one-line descripition of the project."""
+
+        git_dir = get_git_dir()
+        try:
+            projectdesc = open(os.path.join(git_dir, 'description')).readline().strip()
+            if projectdesc and not projectdesc.startswith('Unnamed repository'):
+                return projectdesc
+        except IOError:
+            pass
+
+        return 'UNNAMED PROJECT'
+
+
+class GenericEnvironmentMixin(Environment):
+    def get_pusher(self):
+        return self.osenv.get('USER', self.osenv.get('USERNAME', 'unknown user'))
+
+
+class GitoliteEnvironmentHighPrecMixin(Environment):
+    def get_pusher(self):
+        return self.osenv.get('GL_USER', 'unknown user')
+
+
+class GitoliteEnvironmentLowPrecMixin(
+        ConfigEnvironmentMixin,
+        Environment):
+
+    def get_repo_shortname(self):
+        # The gitolite environment variable $GL_REPO is a pretty good
+        # repo_shortname (though it's probably not as good as a value
+        # the user might have explicitly put in his config).
+        return (
+            self.osenv.get('GL_REPO', None) or
+            super(GitoliteEnvironmentLowPrecMixin, self).get_repo_shortname()
+            )
+
+    @staticmethod
+    def _compile_regex(re_template):
+        return (
+            re.compile(re_template % x)
+            for x in (
+                r'BEGIN\s+USER\s+EMAILS',
+                r'([^\s]+)\s+(.*)',
+                r'END\s+USER\s+EMAILS',
+                ))
+
+    def get_fromaddr(self, change=None):
+        GL_USER = self.osenv.get('GL_USER')
+        if GL_USER is not None:
+            # Find the path to gitolite.conf.  Note that gitolite v3
+            # did away with the GL_ADMINDIR and GL_CONF environment
+            # variables (they are now hard-coded).
+            GL_ADMINDIR = self.osenv.get(
+                'GL_ADMINDIR',
+                os.path.expanduser(os.path.join('~', '.gitolite')))
+            GL_CONF = self.osenv.get(
+                'GL_CONF',
+                os.path.join(GL_ADMINDIR, 'conf', 'gitolite.conf'))
+
+            mailaddress_map = self.config.get('MailaddressMap')
+            # If relative, consider relative to GL_CONF:
+            if mailaddress_map:
+                mailaddress_map = os.path.join(os.path.dirname(GL_CONF),
+                                               mailaddress_map)
+                if os.path.isfile(mailaddress_map):
+                    f = open(mailaddress_map, 'rU')
+                    try:
+                        # Leading '#' is optional
+                        re_begin, re_user, re_end = self._compile_regex(
+                            r'^(?:\s*#)?\s*%s\s*$')
+                        for l in f:
+                            l = l.rstrip('\n')
+                            if re_begin.match(l) or re_end.match(l):
+                                continue  # Ignore these lines
+                            m = re_user.match(l)
+                            if m:
+                                if m.group(1) == GL_USER:
+                                    return m.group(2)
+                                else:
+                                    continue  # Not this user, but not an error
+                            raise ConfigurationException(
+                                "Syntax error in mail address map.\n"
+                                "Check file {}.\n"
+                                "Line: {}".format(mailaddress_map, l))
+
+                    finally:
+                        f.close()
+
+            if os.path.isfile(GL_CONF):
+                f = open(GL_CONF, 'rU')
+                try:
+                    in_user_emails_section = False
+                    re_begin, re_user, re_end = self._compile_regex(
+                        r'^\s*#\s*%s\s*$')
+                    for l in f:
+                        l = l.rstrip('\n')
+                        if not in_user_emails_section:
+                            if re_begin.match(l):
+                                in_user_emails_section = True
+                            continue
+                        if re_end.match(l):
+                            break
+                        m = re_user.match(l)
+                        if m and m.group(1) == GL_USER:
+                            return m.group(2)
+                finally:
+                    f.close()
+        return super(GitoliteEnvironmentLowPrecMixin, self).get_fromaddr(change)
+
+
+class IncrementalDateTime(object):
+    """Simple wrapper to give incremental date/times.
+
+    Each call will result in a date/time a second later than the
+    previous call.  This can be used to falsify email headers, to
+    increase the likelihood that email clients sort the emails
+    correctly."""
+
+    def __init__(self):
+        self.time = time.time()
+        self.next = self.__next__  # Python 2 backward compatibility
+
+    def __next__(self):
+        formatted = formatdate(self.time, True)
+        self.time += 1
+        return formatted
+
+
+class StashEnvironmentHighPrecMixin(Environment):
+    def __init__(self, user=None, repo=None, **kw):
+        super(StashEnvironmentHighPrecMixin,
+              self).__init__(user=user, repo=repo, **kw)
+        self.__user = user
+        self.__repo = repo
+
+    def get_pusher(self):
+        return re.match(r'(.*?)\s*<', self.__user).group(1)
+
+    def get_pusher_email(self):
+        return self.__user
+
+
+class StashEnvironmentLowPrecMixin(Environment):
+    def __init__(self, user=None, repo=None, **kw):
+        super(StashEnvironmentLowPrecMixin, self).__init__(**kw)
+        self.__repo = repo
+        self.__user = user
+
+    def get_repo_shortname(self):
+        return self.__repo
+
+    def get_fromaddr(self, change=None):
+        return self.__user
+
+
+class GerritEnvironmentHighPrecMixin(Environment):
+    def __init__(self, project=None, submitter=None, update_method=None, **kw):
+        super(GerritEnvironmentHighPrecMixin,
+              self).__init__(submitter=submitter, project=project, **kw)
+        self.__project = project
+        self.__submitter = submitter
+        self.__update_method = update_method
+        "Make an 'update_method' value available for templates."
+        self.COMPUTED_KEYS += ['update_method']
+
+    def get_pusher(self):
+        if self.__submitter:
+            if self.__submitter.find('<') != -1:
+                # Submitter has a configured email, we transformed
+                # __submitter into an RFC 2822 string already.
+                return re.match(r'(.*?)\s*<', self.__submitter).group(1)
+            else:
+                # Submitter has no configured email, it's just his name.
+                return self.__submitter
+        else:
+            # If we arrive here, this means someone pushed "Submit" from
+            # the gerrit web UI for the CR (or used one of the programmatic
+            # APIs to do the same, such as gerrit review) and the
+            # merge/push was done by the Gerrit user.  It was technically
+            # triggered by someone else, but sadly we have no way of
+            # determining who that someone else is at this point.
+            return 'Gerrit'  # 'unknown user'?
+
+    def get_pusher_email(self):
+        if self.__submitter:
+            return self.__submitter
+        else:
+            return super(GerritEnvironmentHighPrecMixin, self).get_pusher_email()
+
+    def get_default_ref_ignore_regex(self):
+        default = super(GerritEnvironmentHighPrecMixin, self).get_default_ref_ignore_regex()
+        return default + '|^refs/changes/|^refs/cache-automerge/|^refs/meta/'
+
+    def get_revision_recipients(self, revision):
+        # Merge commits created by Gerrit when users hit "Submit this patchset"
+        # in the Web UI (or do equivalently with REST APIs or the gerrit review
+        # command) are not something users want to see an individual email for.
+        # Filter them out.
+        committer = read_git_output(['log', '--no-walk', '--format=%cN',
+                                     revision.rev.sha1])
+        if committer == 'Gerrit Code Review':
+            return []
+        else:
+            return super(GerritEnvironmentHighPrecMixin, self).get_revision_recipients(revision)
+
+    def get_update_method(self):
+        return self.__update_method
+
+
+class GerritEnvironmentLowPrecMixin(Environment):
+    def __init__(self, project=None, submitter=None, **kw):
+        super(GerritEnvironmentLowPrecMixin, self).__init__(**kw)
+        self.__project = project
+        self.__submitter = submitter
+
+    def get_repo_shortname(self):
+        return self.__project
+
+    def get_fromaddr(self, change=None):
+        if self.__submitter and self.__submitter.find('<') != -1:
+            return self.__submitter
+        else:
+            return super(GerritEnvironmentLowPrecMixin, self).get_fromaddr(change)
+
+
+class Push(object):
+    """Represent an entire push (i.e., a group of ReferenceChanges).
+
+    It is easy to figure out what commits were added to a *branch* by
+    a Reference change:
+
+        git rev-list change.old..change.new
+
+    or removed from a *branch*:
+
+        git rev-list change.new..change.old
+
+    But it is not quite so trivial to determine which entirely new
+    commits were added to the *repository* by a push and which old
+    commits were discarded by a push.  A big part of the job of this
+    class is to figure out these things, and to make sure that new
+    commits are only detailed once even if they were added to multiple
+    references.
+
+    The first step is to determine the "other" references--those
+    unaffected by the current push.  They are computed by listing all
+    references then removing any affected by this push.  The results
+    are stored in Push._other_ref_sha1s.
+
+    The commits contained in the repository before this push were
+
+        git rev-list other1 other2 other3 ... change1.old change2.old ...
+
+    Where "changeN.old" is the old value of one of the references
+    affected by this push.
+
+    The commits contained in the repository after this push are
+
+        git rev-list other1 other2 other3 ... change1.new change2.new ...
+
+    The commits added by this push are the difference between these
+    two sets, which can be written
+
+        git rev-list \
+            ^other1 ^other2 ... \
+            ^change1.old ^change2.old ... \
+            change1.new change2.new ...
+
+    The commits removed by this push can be computed by
+
+        git rev-list \
+            ^other1 ^other2 ... \
+            ^change1.new ^change2.new ... \
+            change1.old change2.old ...
+
+    The last point is that it is possible that other pushes are
+    occurring simultaneously to this one, so reference values can
+    change at any time.  It is impossible to eliminate all race
+    conditions, but we reduce the window of time during which problems
+    can occur by translating reference names to SHA1s as soon as
+    possible and working with SHA1s thereafter (because SHA1s are
+    immutable)."""
+
+    # A map {(changeclass, changetype): integer} specifying the order
+    # that reference changes will be processed if multiple reference
+    # changes are included in a single push.  The order is significant
+    # mostly because new commit notifications are threaded together
+    # with the first reference change that includes the commit.  The
+    # following order thus causes commits to be grouped with branch
+    # changes (as opposed to tag changes) if possible.
+    SORT_ORDER = dict(
+        (value, i) for (i, value) in enumerate([
+            (BranchChange, 'update'),
+            (BranchChange, 'create'),
+            (AnnotatedTagChange, 'update'),
+            (AnnotatedTagChange, 'create'),
+            (NonAnnotatedTagChange, 'update'),
+            (NonAnnotatedTagChange, 'create'),
+            (BranchChange, 'delete'),
+            (AnnotatedTagChange, 'delete'),
+            (NonAnnotatedTagChange, 'delete'),
+            (OtherReferenceChange, 'update'),
+            (OtherReferenceChange, 'create'),
+            (OtherReferenceChange, 'delete'),
+            ])
+        )
+
+    def __init__(self, environment, changes, ignore_other_refs=False):
+        self.changes = sorted(changes, key=self._sort_key)
+        self.__other_ref_sha1s = None
+        self.__cached_commits_spec = {}
+        self.environment = environment
+
+        if ignore_other_refs:
+            self.__other_ref_sha1s = set()
+
+    @classmethod
+    def _sort_key(klass, change):
+        return (klass.SORT_ORDER[change.__class__, change.change_type], change.refname,)
+
+    @property
+    def _other_ref_sha1s(self):
+        """The GitObjects referred to by references unaffected by this push.
+        """
+        if self.__other_ref_sha1s is None:
+            # The refnames being changed by this push:
+            updated_refs = set(
+                change.refname
+                for change in self.changes
+                )
+
+            # The SHA-1s of commits referred to by all references in this
+            # repository *except* updated_refs:
+            sha1s = set()
+            fmt = (
+                '%(objectname) %(objecttype) %(refname)\n'
+                '%(*objectname) %(*objecttype) %(refname)'
+                )
+            ref_filter_regex, is_inclusion_filter = \
+                self.environment.get_ref_filter_regex()
+            for line in read_git_lines(
+                    ['for-each-ref', '--format=%s' % (fmt,)]):
+                (sha1, type, name) = line.split(' ', 2)
+                if (sha1 and type == 'commit' and
+                        name not in updated_refs and
+                        include_ref(name, ref_filter_regex, is_inclusion_filter)):
+                    sha1s.add(sha1)
+
+            self.__other_ref_sha1s = sha1s
+
+        return self.__other_ref_sha1s
+
+    def _get_commits_spec_incl(self, new_or_old, reference_change=None):
+        """Get new or old SHA-1 from one or each of the changed refs.
+
+        Return a list of SHA-1 commit identifier strings suitable as
+        arguments to 'git rev-list' (or 'git log' or ...).  The
+        returned identifiers are either the old or new values from one
+        or all of the changed references, depending on the values of
+        new_or_old and reference_change.
+
+        new_or_old is either the string 'new' or the string 'old'.  If
+        'new', the returned SHA-1 identifiers are the new values from
+        each changed reference.  If 'old', the SHA-1 identifiers are
+        the old values from each changed reference.
+
+        If reference_change is specified and not None, only the new or
+        old reference from the specified reference is included in the
+        return value.
+
+        This function returns None if there are no matching revisions
+        (e.g., because a branch was deleted and new_or_old is 'new').
+        """
+
+        if not reference_change:
+            incl_spec = sorted(
+                getattr(change, new_or_old).sha1
+                for change in self.changes
+                if getattr(change, new_or_old)
+                )
+            if not incl_spec:
+                incl_spec = None
+        elif not getattr(reference_change, new_or_old).commit_sha1:
+            incl_spec = None
+        else:
+            incl_spec = [getattr(reference_change, new_or_old).commit_sha1]
+        return incl_spec
+
+    def _get_commits_spec_excl(self, new_or_old):
+        """Get exclusion revisions for determining new or discarded commits.
+
+        Return a list of strings suitable as arguments to 'git
+        rev-list' (or 'git log' or ...) that will exclude all
+        commits that, depending on the value of new_or_old, were
+        either previously in the repository (useful for determining
+        which commits are new to the repository) or currently in the
+        repository (useful for determining which commits were
+        discarded from the repository).
+
+        new_or_old is either the string 'new' or the string 'old'.  If
+        'new', the commits to be excluded are those that were in the
+        repository before the push.  If 'old', the commits to be
+        excluded are those that are currently in the repository.  """
+
+        old_or_new = {'old': 'new', 'new': 'old'}[new_or_old]
+        excl_revs = self._other_ref_sha1s.union(
+            getattr(change, old_or_new).sha1
+            for change in self.changes
+            if getattr(change, old_or_new).type in ['commit', 'tag']
+            )
+        return ['^' + sha1 for sha1 in sorted(excl_revs)]
+
+    def get_commits_spec(self, new_or_old, reference_change=None):
+        """Get rev-list arguments for added or discarded commits.
+
+        Return a list of strings suitable as arguments to 'git
+        rev-list' (or 'git log' or ...) that select those commits
+        that, depending on the value of new_or_old, are either new to
+        the repository or were discarded from the repository.
+
+        new_or_old is either the string 'new' or the string 'old'.  If
+        'new', the returned list is used to select commits that are
+        new to the repository.  If 'old', the returned value is used
+        to select the commits that have been discarded from the
+        repository.
+
+        If reference_change is specified and not None, the new or
+        discarded commits are limited to those that are reachable from
+        the new or old value of the specified reference.
+
+        This function returns None if there are no added (or discarded)
+        revisions.
+        """
+        key = (new_or_old, reference_change)
+        if key not in self.__cached_commits_spec:
+            ret = self._get_commits_spec_incl(new_or_old, reference_change)
+            if ret is not None:
+                ret.extend(self._get_commits_spec_excl(new_or_old))
+            self.__cached_commits_spec[key] = ret
+        return self.__cached_commits_spec[key]
+
+    def get_new_commits(self, reference_change=None):
+        """Return a list of commits added by this push.
+
+        Return a list of the object names of commits that were added
+        by the part of this push represented by reference_change.  If
+        reference_change is None, then return a list of *all* commits
+        added by this push."""
+
+        spec = self.get_commits_spec('new', reference_change)
+        return git_rev_list(spec)
+
+    def get_discarded_commits(self, reference_change):
+        """Return a list of commits discarded by this push.
+
+        Return a list of the object names of commits that were
+        entirely discarded from the repository by the part of this
+        push represented by reference_change."""
+
+        spec = self.get_commits_spec('old', reference_change)
+        return git_rev_list(spec)
+
+    def send_emails(self, mailer, body_filter=None):
+        """Use send all of the notification emails needed for this push.
+
+        Use send all of the notification emails (including reference
+        change emails and commit emails) needed for this push.  Send
+        the emails using mailer.  If body_filter is not None, then use
+        it to filter the lines that are intended for the email
+        body."""
+
+        # The sha1s of commits that were introduced by this push.
+        # They will be removed from this set as they are processed, to
+        # guarantee that one (and only one) email is generated for
+        # each new commit.
+        unhandled_sha1s = set(self.get_new_commits())
+        send_date = IncrementalDateTime()
+        for change in self.changes:
+            sha1s = []
+            for sha1 in reversed(list(self.get_new_commits(change))):
+                if sha1 in unhandled_sha1s:
+                    sha1s.append(sha1)
+                    unhandled_sha1s.remove(sha1)
+
+            # Check if we've got anyone to send to
+            if not change.recipients:
+                change.environment.log_warning(
+                    '*** no recipients configured so no email will be sent\n'
+                    '*** for %r update %s->%s'
+                    % (change.refname, change.old.sha1, change.new.sha1,)
+                    )
+            else:
+                if not change.environment.quiet:
+                    change.environment.log_msg(
+                        'Sending notification emails to: %s' % (change.recipients,))
+                extra_values = {'send_date': next(send_date)}
+
+                rev = change.send_single_combined_email(sha1s)
+                if rev:
+                    mailer.send(
+                        change.generate_combined_email(self, rev, body_filter, extra_values),
+                        rev.recipients,
+                        )
+                    # This change is now fully handled; no need to handle
+                    # individual revisions any further.
+                    continue
+                else:
+                    mailer.send(
+                        change.generate_email(self, body_filter, extra_values),
+                        change.recipients,
+                        )
+
+            max_emails = change.environment.maxcommitemails
+            if max_emails and len(sha1s) > max_emails:
+                change.environment.log_warning(
+                    '*** Too many new commits (%d), not sending commit emails.\n' % len(sha1s) +
+                    '*** Try setting multimailhook.maxCommitEmails to a greater value\n' +
+                    '*** Currently, multimailhook.maxCommitEmails=%d' % max_emails
+                    )
+                return
+
+            for (num, sha1) in enumerate(sha1s):
+                rev = Revision(change, GitObject(sha1), num=num + 1, tot=len(sha1s))
+                if len(rev.parents) > 1 and change.environment.excludemergerevisions:
+                    # skipping a merge commit
+                    continue
+                if not rev.recipients and rev.cc_recipients:
+                    change.environment.log_msg('*** Replacing Cc: with To:')
+                    rev.recipients = rev.cc_recipients
+                    rev.cc_recipients = None
+                if rev.recipients:
+                    extra_values = {'send_date': next(send_date)}
+                    mailer.send(
+                        rev.generate_email(self, body_filter, extra_values),
+                        rev.recipients,
+                        )
+
+        # Consistency check:
+        if unhandled_sha1s:
+            change.environment.log_error(
+                'ERROR: No emails were sent for the following new commits:\n'
+                '    %s'
+                % ('\n    '.join(sorted(unhandled_sha1s)),)
+                )
+
+
+def include_ref(refname, ref_filter_regex, is_inclusion_filter):
+    does_match = bool(ref_filter_regex.search(refname))
+    if is_inclusion_filter:
+        return does_match
+    else:  # exclusion filter -- we include the ref if the regex doesn't match
+        return not does_match
+
+
+def run_as_post_receive_hook(environment, mailer):
+    environment.check()
+    send_filter_regex, send_is_inclusion_filter = environment.get_ref_filter_regex(True)
+    ref_filter_regex, is_inclusion_filter = environment.get_ref_filter_regex(False)
+    changes = []
+    while True:
+        line = read_line(sys.stdin)
+        if line == '':
+            break
+        (oldrev, newrev, refname) = line.strip().split(' ', 2)
+        environment.get_logger().debug(
+            "run_as_post_receive_hook: oldrev=%s, newrev=%s, refname=%s" %
+            (oldrev, newrev, refname))
+
+        if not include_ref(refname, ref_filter_regex, is_inclusion_filter):
+            continue
+        if not include_ref(refname, send_filter_regex, send_is_inclusion_filter):
+            continue
+        changes.append(
+            ReferenceChange.create(environment, oldrev, newrev, refname)
+            )
+    if not changes:
+        mailer.close()
+        return
+    push = Push(environment, changes)
+    try:
+        push.send_emails(mailer, body_filter=environment.filter_body)
+    finally:
+        mailer.close()
+
+
+def run_as_update_hook(environment, mailer, refname, oldrev, newrev, force_send=False):
+    environment.check()
+    send_filter_regex, send_is_inclusion_filter = environment.get_ref_filter_regex(True)
+    ref_filter_regex, is_inclusion_filter = environment.get_ref_filter_regex(False)
+    if not include_ref(refname, ref_filter_regex, is_inclusion_filter):
+        return
+    if not include_ref(refname, send_filter_regex, send_is_inclusion_filter):
+        return
+    changes = [
+        ReferenceChange.create(
+            environment,
+            read_git_output(['rev-parse', '--verify', oldrev]),
+            read_git_output(['rev-parse', '--verify', newrev]),
+            refname,
+            ),
+        ]
+    if not changes:
+        mailer.close()
+        return
+    push = Push(environment, changes, force_send)
+    try:
+        push.send_emails(mailer, body_filter=environment.filter_body)
+    finally:
+        mailer.close()
+
+
+def check_ref_filter(environment):
+    send_filter_regex, send_is_inclusion = environment.get_ref_filter_regex(True)
+    ref_filter_regex, ref_is_inclusion = environment.get_ref_filter_regex(False)
+
+    def inc_exc_lusion(b):
+        if b:
+            return 'inclusion'
+        else:
+            return 'exclusion'
+
+    if send_filter_regex:
+        sys.stdout.write("DoSend/DontSend filter regex (" +
+                         (inc_exc_lusion(send_is_inclusion)) +
+                         '): ' + send_filter_regex.pattern +
+                         '\n')
+    if send_filter_regex:
+        sys.stdout.write("Include/Exclude filter regex (" +
+                         (inc_exc_lusion(ref_is_inclusion)) +
+                         '): ' + ref_filter_regex.pattern +
+                         '\n')
+    sys.stdout.write(os.linesep)
+
+    sys.stdout.write(
+        "Refs marked as EXCLUDE are excluded by either refFilterInclusionRegex\n"
+        "or refFilterExclusionRegex. No emails will be sent for commits included\n"
+        "in these refs.\n"
+        "Refs marked as DONT-SEND are excluded by either refFilterDoSendRegex or\n"
+        "refFilterDontSendRegex, but not by either refFilterInclusionRegex or\n"
+        "refFilterExclusionRegex. Emails will be sent for commits included in these\n"
+        "refs only when the commit reaches a ref which isn't excluded.\n"
+        "Refs marked as DO-SEND are not excluded by any filter. Emails will\n"
+        "be sent normally for commits included in these refs.\n")
+
+    sys.stdout.write(os.linesep)
+
+    for refname in read_git_lines(['for-each-ref', '--format', '%(refname)']):
+        sys.stdout.write(refname)
+        if not include_ref(refname, ref_filter_regex, ref_is_inclusion):
+            sys.stdout.write(' EXCLUDE')
+        elif not include_ref(refname, send_filter_regex, send_is_inclusion):
+            sys.stdout.write(' DONT-SEND')
+        else:
+            sys.stdout.write(' DO-SEND')
+
+        sys.stdout.write(os.linesep)
+
+
+def show_env(environment, out):
+    out.write('Environment values:\n')
+    for (k, v) in sorted(environment.get_values().items()):
+        if k:  # Don't show the {'' : ''} pair.
+            out.write('    %s : %r\n' % (k, v))
+    out.write('\n')
+    # Flush to avoid interleaving with further log output
+    out.flush()
+
+
+def check_setup(environment):
+    environment.check()
+    show_env(environment, sys.stdout)
+    sys.stdout.write("Now, checking that git-multimail's standard input "
+                     "is properly set ..." + os.linesep)
+    sys.stdout.write("Please type some text and then press Return" + os.linesep)
+    stdin = sys.stdin.readline()
+    sys.stdout.write("You have just entered:" + os.linesep)
+    sys.stdout.write(stdin)
+    sys.stdout.write("git-multimail seems properly set up." + os.linesep)
+
+
+def choose_mailer(config, environment):
+    mailer = config.get('mailer', default='sendmail')
+
+    if mailer == 'smtp':
+        smtpserver = config.get('smtpserver', default='localhost')
+        smtpservertimeout = float(config.get('smtpservertimeout', default=10.0))
+        smtpserverdebuglevel = int(config.get('smtpserverdebuglevel', default=0))
+        smtpencryption = config.get('smtpencryption', default='none')
+        smtpuser = config.get('smtpuser', default='')
+        smtppass = config.get('smtppass', default='')
+        smtpcacerts = config.get('smtpcacerts', default='')
+        mailer = SMTPMailer(
+            environment,
+            envelopesender=(environment.get_sender() or environment.get_fromaddr()),
+            smtpserver=smtpserver, smtpservertimeout=smtpservertimeout,
+            smtpserverdebuglevel=smtpserverdebuglevel,
+            smtpencryption=smtpencryption,
+            smtpuser=smtpuser,
+            smtppass=smtppass,
+            smtpcacerts=smtpcacerts
+            )
+    elif mailer == 'sendmail':
+        command = config.get('sendmailcommand')
+        if command:
+            command = shlex.split(command)
+        mailer = SendMailer(environment,
+                            command=command, envelopesender=environment.get_sender())
+    else:
+        environment.log_error(
+            'fatal: multimailhook.mailer is set to an incorrect value: "%s"\n' % mailer +
+            'please use one of "smtp" or "sendmail".'
+            )
+        sys.exit(1)
+    return mailer
+
+
+KNOWN_ENVIRONMENTS = {
+    'generic': {'highprec': GenericEnvironmentMixin},
+    'gitolite': {'highprec': GitoliteEnvironmentHighPrecMixin,
+                 'lowprec': GitoliteEnvironmentLowPrecMixin},
+    'stash': {'highprec': StashEnvironmentHighPrecMixin,
+              'lowprec': StashEnvironmentLowPrecMixin},
+    'gerrit': {'highprec': GerritEnvironmentHighPrecMixin,
+               'lowprec': GerritEnvironmentLowPrecMixin},
+    }
+
+
+def choose_environment(config, osenv=None, env=None, recipients=None,
+                       hook_info=None):
+    env_name = choose_environment_name(config, env, osenv)
+    environment_klass = build_environment_klass(env_name)
+    env = build_environment(environment_klass, env_name, config,
+                            osenv, recipients, hook_info)
+    return env
+
+
+def choose_environment_name(config, env, osenv):
+    if not osenv:
+        osenv = os.environ
+
+    if not env:
+        env = config.get('environment')
+
+    if not env:
+        if 'GL_USER' in osenv and 'GL_REPO' in osenv:
+            env = 'gitolite'
+        else:
+            env = 'generic'
+    return env
+
+
+COMMON_ENVIRONMENT_MIXINS = [
+    ConfigRecipientsEnvironmentMixin,
+    CLIRecipientsEnvironmentMixin,
+    ConfigRefFilterEnvironmentMixin,
+    ProjectdescEnvironmentMixin,
+    ConfigMaxlinesEnvironmentMixin,
+    ComputeFQDNEnvironmentMixin,
+    ConfigFilterLinesEnvironmentMixin,
+    PusherDomainEnvironmentMixin,
+    ConfigOptionsEnvironmentMixin,
+    ]
+
+
+def build_environment_klass(env_name):
+    if 'class' in KNOWN_ENVIRONMENTS[env_name]:
+        return KNOWN_ENVIRONMENTS[env_name]['class']
+
+    environment_mixins = []
+    known_env = KNOWN_ENVIRONMENTS[env_name]
+    if 'highprec' in known_env:
+        high_prec_mixin = known_env['highprec']
+        environment_mixins.append(high_prec_mixin)
+    environment_mixins = environment_mixins + COMMON_ENVIRONMENT_MIXINS
+    if 'lowprec' in known_env:
+        low_prec_mixin = known_env['lowprec']
+        environment_mixins.append(low_prec_mixin)
+    environment_mixins.append(Environment)
+    klass_name = env_name.capitalize() + 'Environment'
+    environment_klass = type(
+        klass_name,
+        tuple(environment_mixins),
+        {},
+        )
+    KNOWN_ENVIRONMENTS[env_name]['class'] = environment_klass
+    return environment_klass
+
+
+GerritEnvironment = build_environment_klass('gerrit')
+StashEnvironment = build_environment_klass('stash')
+GitoliteEnvironment = build_environment_klass('gitolite')
+GenericEnvironment = build_environment_klass('generic')
+
+
+def build_environment(environment_klass, env, config,
+                      osenv, recipients, hook_info):
+    environment_kw = {
+        'osenv': osenv,
+        'config': config,
+        }
+
+    if env == 'stash':
+        environment_kw['user'] = hook_info['stash_user']
+        environment_kw['repo'] = hook_info['stash_repo']
+    elif env == 'gerrit':
+        environment_kw['project'] = hook_info['project']
+        environment_kw['submitter'] = hook_info['submitter']
+        environment_kw['update_method'] = hook_info['update_method']
+
+    environment_kw['cli_recipients'] = recipients
+
+    return environment_klass(**environment_kw)
+
+
+def get_version():
+    oldcwd = os.getcwd()
+    try:
+        try:
+            os.chdir(os.path.dirname(os.path.realpath(__file__)))
+            git_version = read_git_output(['describe', '--tags', 'HEAD'])
+            if git_version == __version__:
+                return git_version
+            else:
+                return '%s (%s)' % (__version__, git_version)
+        except:
+            pass
+    finally:
+        os.chdir(oldcwd)
+    return __version__
+
+
+def compute_gerrit_options(options, args, required_gerrit_options,
+                           raw_refname):
+    if None in required_gerrit_options:
+        raise SystemExit("Error: Specify all of --oldrev, --newrev, --refname, "
+                         "and --project; or none of them.")
+
+    if options.environment not in (None, 'gerrit'):
+        raise SystemExit("Non-gerrit environments incompatible with --oldrev, "
+                         "--newrev, --refname, and --project")
+    options.environment = 'gerrit'
+
+    if args:
+        raise SystemExit("Error: Positional parameters not allowed with "
+                         "--oldrev, --newrev, and --refname.")
+
+    # Gerrit oddly omits 'refs/heads/' in the refname when calling
+    # ref-updated hook; put it back.
+    git_dir = get_git_dir()
+    if (not os.path.exists(os.path.join(git_dir, raw_refname)) and
+        os.path.exists(os.path.join(git_dir, 'refs', 'heads',
+                                    raw_refname))):
+        options.refname = 'refs/heads/' + options.refname
+
+    # New revisions can appear in a gerrit repository either due to someone
+    # pushing directly (in which case options.submitter will be set), or they
+    # can press "Submit this patchset" in the web UI for some CR (in which
+    # case options.submitter will not be set and gerrit will not have provided
+    # us the information about who pressed the button).
+    #
+    # Note for the nit-picky: I'm lumping in REST API calls and the ssh
+    # gerrit review command in with "Submit this patchset" button, since they
+    # have the same effect.
+    if options.submitter:
+        update_method = 'pushed'
+        # The submitter argument is almost an RFC 2822 email address; change it
+        # from 'User Name (email@domain)' to 'User Name ' so it is
+        options.submitter = options.submitter.replace('(', '<').replace(')', '>')
+    else:
+        update_method = 'submitted'
+        # Gerrit knew who submitted this patchset, but threw that information
+        # away when it invoked this hook.  However, *IF* Gerrit created a
+        # merge to bring the patchset in (project 'Submit Type' is either
+        # "Always Merge", or is "Merge if Necessary" and happens to be
+        # necessary for this particular CR), then it will have the committer
+        # of that merge be 'Gerrit Code Review' and the author will be the
+        # person who requested the submission of the CR.  Since this is fairly
+        # likely for most gerrit installations (of a reasonable size), it's
+        # worth the extra effort to try to determine the actual submitter.
+        rev_info = read_git_lines(['log', '--no-walk', '--merges',
+                                   '--format=%cN%n%aN <%aE>', options.newrev])
+        if rev_info and rev_info[0] == 'Gerrit Code Review':
+            options.submitter = rev_info[1]
+
+    # We pass back refname, oldrev, newrev as args because then the
+    # gerrit ref-updated hook is much like the git update hook
+    return (options,
+            [options.refname, options.oldrev, options.newrev],
+            {'project': options.project, 'submitter': options.submitter,
+             'update_method': update_method})
+
+
+def check_hook_specific_args(options, args):
+    raw_refname = options.refname
+    # Convert each string option unicode for Python3.
+    if PYTHON3:
+        opts = ['environment', 'recipients', 'oldrev', 'newrev', 'refname',
+                'project', 'submitter', 'stash_user', 'stash_repo']
+        for opt in opts:
+            if not hasattr(options, opt):
+                continue
+            obj = getattr(options, opt)
+            if obj:
+                enc = obj.encode('utf-8', 'surrogateescape')
+                dec = enc.decode('utf-8', 'replace')
+                setattr(options, opt, dec)
+
+    # First check for stash arguments
+    if (options.stash_user is None) != (options.stash_repo is None):
+        raise SystemExit("Error: Specify both of --stash-user and "
+                         "--stash-repo or neither.")
+    if options.stash_user:
+        options.environment = 'stash'
+        return options, args, {'stash_user': options.stash_user,
+                               'stash_repo': options.stash_repo}
+
+    # Finally, check for gerrit specific arguments
+    required_gerrit_options = (options.oldrev, options.newrev, options.refname,
+                               options.project)
+    if required_gerrit_options != (None,) * 4:
+        return compute_gerrit_options(options, args, required_gerrit_options,
+                                      raw_refname)
+
+    # No special options in use, just return what we started with
+    return options, args, {}
+
+
+class Logger(object):
+    def parse_verbose(self, verbose):
+        if verbose > 0:
+            return logging.DEBUG
+        else:
+            return logging.INFO
+
+    def create_log_file(self, environment, name, path, verbosity):
+        log_file = logging.getLogger(name)
+        file_handler = logging.FileHandler(path)
+        log_fmt = logging.Formatter("%(asctime)s [%(levelname)-5.5s]  %(message)s")
+        file_handler.setFormatter(log_fmt)
+        log_file.addHandler(file_handler)
+        log_file.setLevel(verbosity)
+        return log_file
+
+    def __init__(self, environment):
+        self.environment = environment
+        self.loggers = []
+        stderr_log = logging.getLogger('git_multimail.stderr')
+
+        class EncodedStderr(object):
+            def write(self, x):
+                write_str(sys.stderr, x)
+
+            def flush(self):
+                sys.stderr.flush()
+
+        stderr_handler = logging.StreamHandler(EncodedStderr())
+        stderr_log.addHandler(stderr_handler)
+        stderr_log.setLevel(self.parse_verbose(environment.verbose))
+        self.loggers.append(stderr_log)
+
+        if environment.debug_log_file is not None:
+            debug_log_file = self.create_log_file(
+                environment, 'git_multimail.debug', environment.debug_log_file, logging.DEBUG)
+            self.loggers.append(debug_log_file)
+
+        if environment.log_file is not None:
+            log_file = self.create_log_file(
+                environment, 'git_multimail.file', environment.log_file, logging.INFO)
+            self.loggers.append(log_file)
+
+        if environment.error_log_file is not None:
+            error_log_file = self.create_log_file(
+                environment, 'git_multimail.error', environment.error_log_file, logging.ERROR)
+            self.loggers.append(error_log_file)
+
+    def info(self, msg, *args, **kwargs):
+        for l in self.loggers:
+            l.info(msg, *args, **kwargs)
+
+    def debug(self, msg, *args, **kwargs):
+        for l in self.loggers:
+            l.debug(msg, *args, **kwargs)
+
+    def warning(self, msg, *args, **kwargs):
+        for l in self.loggers:
+            l.warning(msg, *args, **kwargs)
+
+    def error(self, msg, *args, **kwargs):
+        for l in self.loggers:
+            l.error(msg, *args, **kwargs)
+
+
+def main(args):
+    parser = optparse.OptionParser(
+        description=__doc__,
+        usage='%prog [OPTIONS]\n   or: %prog [OPTIONS] REFNAME OLDREV NEWREV',
+        )
+
+    parser.add_option(
+        '--environment', '--env', action='store', type='choice',
+        choices=list(KNOWN_ENVIRONMENTS.keys()), default=None,
+        help=(
+            'Choose type of environment is in use.  Default is taken from '
+            'multimailhook.environment if set; otherwise "generic".'
+            ),
+        )
+    parser.add_option(
+        '--stdout', action='store_true', default=False,
+        help='Output emails to stdout rather than sending them.',
+        )
+    parser.add_option(
+        '--recipients', action='store', default=None,
+        help='Set list of email recipients for all types of emails.',
+        )
+    parser.add_option(
+        '--show-env', action='store_true', default=False,
+        help=(
+            'Write to stderr the values determined for the environment '
+            '(intended for debugging purposes), then proceed normally.'
+            ),
+        )
+    parser.add_option(
+        '--force-send', action='store_true', default=False,
+        help=(
+            'Force sending refchange email when using as an update hook. '
+            'This is useful to work around the unreliable new commits '
+            'detection in this mode.'
+            ),
+        )
+    parser.add_option(
+        '-c', metavar="=", action='append',
+        help=(
+            'Pass a configuration parameter through to git.  The value given '
+            'will override values from configuration files.  See the -c option '
+            'of git(1) for more details.  (Only works with git >= 1.7.3)'
+            ),
+        )
+    parser.add_option(
+        '--version', '-v', action='store_true', default=False,
+        help=(
+            "Display git-multimail's version"
+            ),
+        )
+
+    parser.add_option(
+        '--python-version', action='store_true', default=False,
+        help=(
+            "Display the version of Python used by git-multimail"
+            ),
+        )
+
+    parser.add_option(
+        '--check-ref-filter', action='store_true', default=False,
+        help=(
+            'List refs and show information on how git-multimail '
+            'will process them.'
+            )
+        )
+
+    # The following options permit this script to be run as a gerrit
+    # ref-updated hook.  See e.g.
+    # code.google.com/p/gerrit/source/browse/Documentation/config-hooks.txt
+    # We suppress help for these items, since these are specific to gerrit,
+    # and we don't want users directly using them any way other than how the
+    # gerrit ref-updated hook is called.
+    parser.add_option('--oldrev', action='store', help=optparse.SUPPRESS_HELP)
+    parser.add_option('--newrev', action='store', help=optparse.SUPPRESS_HELP)
+    parser.add_option('--refname', action='store', help=optparse.SUPPRESS_HELP)
+    parser.add_option('--project', action='store', help=optparse.SUPPRESS_HELP)
+    parser.add_option('--submitter', action='store', help=optparse.SUPPRESS_HELP)
+
+    # The following allow this to be run as a stash asynchronous post-receive
+    # hook (almost identical to a git post-receive hook but triggered also for
+    # merges of pull requests from the UI).  We suppress help for these items,
+    # since these are specific to stash.
+    parser.add_option('--stash-user', action='store', help=optparse.SUPPRESS_HELP)
+    parser.add_option('--stash-repo', action='store', help=optparse.SUPPRESS_HELP)
+
+    (options, args) = parser.parse_args(args)
+    (options, args, hook_info) = check_hook_specific_args(options, args)
+
+    if options.version:
+        sys.stdout.write('git-multimail version ' + get_version() + '\n')
+        return
+
+    if options.python_version:
+        sys.stdout.write('Python version ' + sys.version + '\n')
+        return
+
+    if options.c:
+        Config.add_config_parameters(options.c)
+
+    config = Config('multimailhook')
+
+    environment = None
+    try:
+        environment = choose_environment(
+            config, osenv=os.environ,
+            env=options.environment,
+            recipients=options.recipients,
+            hook_info=hook_info,
+            )
+
+        if options.show_env:
+            show_env(environment, sys.stderr)
+
+        if options.stdout or environment.stdout:
+            mailer = OutputMailer(sys.stdout, environment)
+        else:
+            mailer = choose_mailer(config, environment)
+
+        must_check_setup = os.environ.get('GIT_MULTIMAIL_CHECK_SETUP')
+        if must_check_setup == '':
+            must_check_setup = False
+        if options.check_ref_filter:
+            check_ref_filter(environment)
+        elif must_check_setup:
+            check_setup(environment)
+        # Dual mode: if arguments were specified on the command line, run
+        # like an update hook; otherwise, run as a post-receive hook.
+        elif args:
+            if len(args) != 3:
+                parser.error('Need zero or three non-option arguments')
+            (refname, oldrev, newrev) = args
+            environment.get_logger().debug(
+                "run_as_update_hook: refname=%s, oldrev=%s, newrev=%s, force_send=%s" %
+                (refname, oldrev, newrev, options.force_send))
+            run_as_update_hook(environment, mailer, refname, oldrev, newrev, options.force_send)
+        else:
+            run_as_post_receive_hook(environment, mailer)
+    except ConfigurationException:
+        sys.exit(sys.exc_info()[1])
+    except SystemExit:
+        raise
+    except Exception:
+        t, e, tb = sys.exc_info()
+        import traceback
+        sys.stderr.write('\n')  # Avoid mixing message with previous output
+        msg = (
+            'Exception \'' + t.__name__ +
+            '\' raised. Please report this as a bug to\n'
+            'https://github.com/git-multimail/git-multimail/issues\n'
+            'with the information below:\n\n'
+            'git-multimail version ' + get_version() + '\n'
+            'Python version ' + sys.version + '\n' +
+            traceback.format_exc())
+        try:
+            environment.get_logger().error(msg)
+        except:
+            sys.stderr.write(msg)
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])
diff --git a/contrib/hooks/multimail/migrate-mailhook-config b/contrib/hooks/multimail/migrate-mailhook-config
new file mode 100755
index 000000000000..241ba22fa3c8
--- /dev/null
+++ b/contrib/hooks/multimail/migrate-mailhook-config
@@ -0,0 +1,274 @@
+#! /usr/bin/env python
+
+"""Migrate a post-receive-email configuration to be usable with git_multimail.py.
+
+See README.migrate-from-post-receive-email for more information.
+
+"""
+
+import sys
+import optparse
+
+from git_multimail import CommandError
+from git_multimail import Config
+from git_multimail import read_output
+
+
+OLD_NAMES = [
+    'mailinglist',
+    'announcelist',
+    'envelopesender',
+    'emailprefix',
+    'showrev',
+    'emailmaxlines',
+    'diffopts',
+    'scancommitforcc',
+    ]
+
+NEW_NAMES = [
+    'environment',
+    'reponame',
+    'mailinglist',
+    'refchangelist',
+    'commitlist',
+    'announcelist',
+    'announceshortlog',
+    'envelopesender',
+    'administrator',
+    'emailprefix',
+    'emailmaxlines',
+    'diffopts',
+    'emaildomain',
+    'scancommitforcc',
+    ]
+
+
+INFO = """\
+
+SUCCESS!
+
+Your post-receive-email configuration has been converted to
+git-multimail format.  Please see README and
+README.migrate-from-post-receive-email to learn about other
+git-multimail configuration possibilities.
+
+For example, git-multimail has the following new options with no
+equivalent in post-receive-email.  You might want to read about them
+to see if they would be useful in your situation:
+
+"""
+
+
+def _check_old_config_exists(old):
+    """Check that at least one old configuration value is set."""
+
+    for name in OLD_NAMES:
+        if name in old:
+            return True
+
+    return False
+
+
+def _check_new_config_clear(new):
+    """Check that none of the new configuration names are set."""
+
+    retval = True
+    for name in NEW_NAMES:
+        if name in new:
+            if retval:
+                sys.stderr.write('INFO: The following configuration values already exist:\n\n')
+            sys.stderr.write('    "%s.%s"\n' % (new.section, name))
+            retval = False
+
+    return retval
+
+
+def erase_values(config, names):
+    for name in names:
+        if name in config:
+            try:
+                sys.stderr.write('...unsetting "%s.%s"\n' % (config.section, name))
+                config.unset_all(name)
+            except CommandError:
+                sys.stderr.write(
+                    '\nWARNING: could not unset "%s.%s".  '
+                    'Perhaps it is not set at the --local level?\n\n'
+                    % (config.section, name)
+                    )
+
+
+def is_section_empty(section, local):
+    """Return True iff the specified configuration section is empty.
+
+    Iff local is True, use the --local option when invoking 'git
+    config'."""
+
+    if local:
+        local_option = ['--local']
+    else:
+        local_option = []
+
+    try:
+        read_output(
+            ['git', 'config'] +
+            local_option +
+            ['--get-regexp', '^%s\.' % (section,)]
+            )
+    except CommandError:
+        t, e, traceback = sys.exc_info()
+        if e.retcode == 1:
+            # This means that no settings were found.
+            return True
+        else:
+            raise
+    else:
+        return False
+
+
+def remove_section_if_empty(section):
+    """If the specified configuration section is empty, delete it."""
+
+    try:
+        empty = is_section_empty(section, local=True)
+    except CommandError:
+        # Older versions of git do not support the --local option, so
+        # if the first attempt fails, try without --local.
+        try:
+            empty = is_section_empty(section, local=False)
+        except CommandError:
+            sys.stderr.write(
+                '\nINFO: If configuration section "%s.*" is empty, you might want '
+                'to delete it.\n\n'
+                % (section,)
+                )
+            return
+
+    if empty:
+        sys.stderr.write('...removing section "%s.*"\n' % (section,))
+        read_output(['git', 'config', '--remove-section', section])
+    else:
+        sys.stderr.write(
+            '\nINFO: Configuration section "%s.*" still has contents.  '
+            'It will not be deleted.\n\n'
+            % (section,)
+            )
+
+
+def migrate_config(strict=False, retain=False, overwrite=False):
+    old = Config('hooks')
+    new = Config('multimailhook')
+    if not _check_old_config_exists(old):
+        sys.exit(
+            'Your repository has no post-receive-email configuration.  '
+            'Nothing to do.'
+            )
+    if not _check_new_config_clear(new):
+        if overwrite:
+            sys.stderr.write('\nWARNING: Erasing the above values...\n\n')
+            erase_values(new, NEW_NAMES)
+        else:
+            sys.exit(
+                '\nERROR: Refusing to overwrite existing values.  Use the --overwrite\n'
+                'option to continue anyway.'
+                )
+
+    name = 'showrev'
+    if name in old:
+        msg = 'git-multimail does not support "%s.%s"' % (old.section, name,)
+        if strict:
+            sys.exit(
+                'ERROR: %s.\n'
+                'Please unset that value then try again, or run without --strict.'
+                % (msg,)
+                )
+        else:
+            sys.stderr.write('\nWARNING: %s (ignoring).\n\n' % (msg,))
+
+    for name in ['mailinglist', 'announcelist']:
+        if name in old:
+            sys.stderr.write(
+                '...copying "%s.%s" to "%s.%s"\n' % (old.section, name, new.section, name)
+                )
+            old_recipients = old.get_all(name, default=None)
+            old_recipients = ', '.join(o.strip() for o in old_recipients)
+            new.set_recipients(name, old_recipients)
+
+    if strict:
+        sys.stderr.write(
+            '...setting "%s.commitlist" to the empty string\n' % (new.section,)
+            )
+        new.set_recipients('commitlist', '')
+        sys.stderr.write(
+            '...setting "%s.announceshortlog" to "true"\n' % (new.section,)
+            )
+        new.set('announceshortlog', 'true')
+
+    for name in ['envelopesender', 'emailmaxlines', 'diffopts', 'scancommitforcc']:
+        if name in old:
+            sys.stderr.write(
+                '...copying "%s.%s" to "%s.%s"\n' % (old.section, name, new.section, name)
+                )
+            new.set(name, old.get(name))
+
+    name = 'emailprefix'
+    if name in old:
+        sys.stderr.write(
+            '...copying "%s.%s" to "%s.%s"\n' % (old.section, name, new.section, name)
+            )
+        new.set(name, old.get(name))
+    elif strict:
+        sys.stderr.write(
+            '...setting "%s.%s" to "[SCM]" to preserve old subject lines\n'
+            % (new.section, name)
+            )
+        new.set(name, '[SCM]')
+
+    if not retain:
+        erase_values(old, OLD_NAMES)
+        remove_section_if_empty(old.section)
+
+    sys.stderr.write(INFO)
+    for name in NEW_NAMES:
+        if name not in OLD_NAMES:
+            sys.stderr.write('    "%s.%s"\n' % (new.section, name,))
+    sys.stderr.write('\n')
+
+
+def main(args):
+    parser = optparse.OptionParser(
+        description=__doc__,
+        usage='%prog [OPTIONS]',
+        )
+
+    parser.add_option(
+        '--strict', action='store_true', default=False,
+        help=(
+            'Slavishly configure git-multimail as closely as possible to '
+            'the post-receive-email configuration.  Default is to turn '
+            'on some new features that have no equivalent in post-receive-email.'
+            ),
+        )
+    parser.add_option(
+        '--retain', action='store_true', default=False,
+        help=(
+            'Retain the post-receive-email configuration values.  '
+            'Default is to delete them after the new values are set.'
+            ),
+        )
+    parser.add_option(
+        '--overwrite', action='store_true', default=False,
+        help=(
+            'Overwrite any existing git-multimail configuration settings.  '
+            'Default is to abort if such settings already exist.'
+            ),
+        )
+
+    (options, args) = parser.parse_args(args)
+
+    if args:
+        parser.error('Unexpected arguments: %s' % (' '.join(args),))
+
+    migrate_config(strict=options.strict, retain=options.retain, overwrite=options.overwrite)
+
+
+main(sys.argv[1:])
diff --git a/contrib/hooks/multimail/post-receive.example b/contrib/hooks/multimail/post-receive.example
new file mode 100755
index 000000000000..b9bb11834e1f
--- /dev/null
+++ b/contrib/hooks/multimail/post-receive.example
@@ -0,0 +1,101 @@
+#! /usr/bin/env python
+
+"""Example post-receive hook based on git-multimail.
+
+The simplest way to use git-multimail is to use the script
+git_multimail.py directly as a post-receive hook, and to configure it
+using Git's configuration files and command-line parameters.  You can
+also write your own Python wrapper for more advanced configurability,
+using git_multimail.py as a Python module.
+
+This script is a simple example of such a post-receive hook.  It is
+intended to be customized before use; see the comments in the script
+to help you get started.
+
+Using git-multimail as a Python module as done here provides more
+flexibility.  It has the following advantages:
+
+* The tool's behavior can be customized using arbitrary Python code,
+  without having to edit git_multimail.py.
+
+* Configuration settings can be read from other sources; for example,
+  user names and email addresses could be read from LDAP or from a
+  database.  Or the settings can even be hardcoded in the importing
+  Python script, if this is preferred.
+
+This script is a very basic example of how to use git_multimail.py as
+a module.  The comments below explain some of the points at which the
+script's behavior could be changed or customized.
+
+"""
+
+import sys
+
+# If necessary, add the path to the directory containing
+# git_multimail.py to the Python path as follows.  (This is not
+# necessary if git_multimail.py is in the same directory as this
+# script):
+
+#LIBDIR = 'path/to/directory/containing/module'
+#sys.path.insert(0, LIBDIR)
+
+import git_multimail
+
+# It is possible to modify the output templates here; e.g.:
+
+#git_multimail.FOOTER_TEMPLATE = """\
+#
+#-- \n\
+#This email was generated by the wonderful git-multimail tool.
+#"""
+
+
+# Specify which "git config" section contains the configuration for
+# git-multimail:
+config = git_multimail.Config('multimailhook')
+
+# Set some Git configuration variables. Equivalent to passing var=val
+# to "git -c var=val" each time git is called, or to adding the
+# configuration in .git/config (must come before instanciating the
+# environment) :
+#git_multimail.Config.add_config_parameters('multimailhook.commitEmailFormat=html')
+#git_multimail.Config.add_config_parameters(('user.name=foo', 'user.email=foo@example.com'))
+
+# Select the type of environment:
+try:
+    environment = git_multimail.GenericEnvironment(config=config)
+    #environment = git_multimail.GitoliteEnvironment(config=config)
+except git_multimail.ConfigurationException:
+    sys.stderr.write('*** %s\n' % sys.exc_info()[1])
+    sys.exit(1)
+
+
+# Choose the method of sending emails based on the git config:
+mailer = git_multimail.choose_mailer(config, environment)
+
+# Alternatively, you may hardcode the mailer using code like one of
+# the following:
+
+# Use "/usr/sbin/sendmail -oi -t" to send emails.  The envelopesender
+# argument is optional:
+#mailer = git_multimail.SendMailer(
+#    command=['/usr/sbin/sendmail', '-oi', '-t'],
+#    envelopesender='git-repo@example.com',
+#    )
+
+# Use Python's smtplib to send emails.  Both arguments are required.
+#mailer = git_multimail.SMTPMailer(
+#    environment=environment,
+#    envelopesender='git-repo@example.com',
+#    # The smtpserver argument can also include a port number; e.g.,
+#    #     smtpserver='mail.example.com:25'
+#    smtpserver='mail.example.com',
+#    )
+
+# OutputMailer is intended only for testing; it writes the emails to
+# the specified file stream.
+#mailer = git_multimail.OutputMailer(sys.stdout)
+
+
+# Read changes from stdin and send notification emails:
+git_multimail.run_as_post_receive_hook(environment, mailer)
diff --git a/contrib/hooks/post-receive-email b/contrib/hooks/post-receive-email
new file mode 100755
index 000000000000..8747b84334f3
--- /dev/null
+++ b/contrib/hooks/post-receive-email
@@ -0,0 +1,759 @@
+#!/bin/sh
+#
+# Copyright (c) 2007 Andy Parkins
+#
+# An example hook script to mail out commit update information.
+#
+# NOTE: This script is no longer under active development.  There
+# is another script, git-multimail, which is more capable and
+# configurable and is largely backwards-compatible with this script;
+# please see "contrib/hooks/multimail/".  For instructions on how to
+# migrate from post-receive-email to git-multimail, please see
+# "README.migrate-from-post-receive-email" in that directory.
+#
+# This hook sends emails listing new revisions to the repository
+# introduced by the change being reported.  The rule is that (for
+# branch updates) each commit will appear on one email and one email
+# only.
+#
+# This hook is stored in the contrib/hooks directory.  Your distribution
+# will have put this somewhere standard.  You should make this script
+# executable then link to it in the repository you would like to use it in.
+# For example, on debian the hook is stored in
+# /usr/share/git-core/contrib/hooks/post-receive-email:
+#
+#  cd /path/to/your/repository.git
+#  ln -sf /usr/share/git-core/contrib/hooks/post-receive-email hooks/post-receive
+#
+# This hook script assumes it is enabled on the central repository of a
+# project, with all users pushing only to it and not between each other.  It
+# will still work if you don't operate in that style, but it would become
+# possible for the email to be from someone other than the person doing the
+# push.
+#
+# To help with debugging and use on pre-v1.5.1 git servers, this script will
+# also obey the interface of hooks/update, taking its arguments on the
+# command line.  Unfortunately, hooks/update is called once for each ref.
+# To avoid firing one email per ref, this script just prints its output to
+# the screen when used in this mode.  The output can then be redirected if
+# wanted.
+#
+# Config
+# ------
+# hooks.mailinglist
+#   This is the list that all pushes will go to; leave it blank to not send
+#   emails for every ref update.
+# hooks.announcelist
+#   This is the list that all pushes of annotated tags will go to.  Leave it
+#   blank to default to the mailinglist field.  The announce emails lists
+#   the short log summary of the changes since the last annotated tag.
+# hooks.envelopesender
+#   If set then the -f option is passed to sendmail to allow the envelope
+#   sender address to be set
+# hooks.emailprefix
+#   All emails have their subjects prefixed with this prefix, or "[SCM]"
+#   if emailprefix is unset, to aid filtering
+# hooks.showrev
+#   The shell command used to format each revision in the email, with
+#   "%s" replaced with the commit id.  Defaults to "git rev-list -1
+#   --pretty %s", displaying the commit id, author, date and log
+#   message.  To list full patches separated by a blank line, you
+#   could set this to "git show -C %s; echo".
+#   To list a gitweb/cgit URL *and* a full patch for each change set, use this:
+#     "t=%s; printf 'http://.../?id=%%s' \$t; echo;echo; git show -C \$t; echo"
+#   Be careful if "..." contains things that will be expanded by shell "eval"
+#   or printf.
+# hooks.emailmaxlines
+#   The maximum number of lines that should be included in the generated
+#   email body. If not specified, there is no limit.
+#   Lines beyond the limit are suppressed and counted, and a final
+#   line is added indicating the number of suppressed lines.
+# hooks.diffopts
+#   Alternate options for the git diff-tree invocation that shows changes.
+#   Default is "--stat --summary --find-copies-harder". Add -p to those
+#   options to include a unified diff of changes in addition to the usual
+#   summary output.
+#
+# Notes
+# -----
+# All emails include the headers "X-Git-Refname", "X-Git-Oldrev",
+# "X-Git-Newrev", and "X-Git-Reftype" to enable fine tuned filtering and
+# give information for debugging.
+#
+
+# ---------------------------- Functions
+
+#
+# Function to prepare for email generation. This decides what type
+# of update this is and whether an email should even be generated.
+#
+prep_for_email()
+{
+	# --- Arguments
+	oldrev=$(git rev-parse $1)
+	newrev=$(git rev-parse $2)
+	refname="$3"
+
+	# --- Interpret
+	# 0000->1234 (create)
+	# 1234->2345 (update)
+	# 2345->0000 (delete)
+	if expr "$oldrev" : '0*$' >/dev/null
+	then
+		change_type="create"
+	else
+		if expr "$newrev" : '0*$' >/dev/null
+		then
+			change_type="delete"
+		else
+			change_type="update"
+		fi
+	fi
+
+	# --- Get the revision types
+	newrev_type=$(git cat-file -t $newrev 2> /dev/null)
+	oldrev_type=$(git cat-file -t "$oldrev" 2> /dev/null)
+	case "$change_type" in
+	create|update)
+		rev="$newrev"
+		rev_type="$newrev_type"
+		;;
+	delete)
+		rev="$oldrev"
+		rev_type="$oldrev_type"
+		;;
+	esac
+
+	# The revision type tells us what type the commit is, combined with
+	# the location of the ref we can decide between
+	#  - working branch
+	#  - tracking branch
+	#  - unannoted tag
+	#  - annotated tag
+	case "$refname","$rev_type" in
+		refs/tags/*,commit)
+			# un-annotated tag
+			refname_type="tag"
+			short_refname=${refname##refs/tags/}
+			;;
+		refs/tags/*,tag)
+			# annotated tag
+			refname_type="annotated tag"
+			short_refname=${refname##refs/tags/}
+			# change recipients
+			if [ -n "$announcerecipients" ]; then
+				recipients="$announcerecipients"
+			fi
+			;;
+		refs/heads/*,commit)
+			# branch
+			refname_type="branch"
+			short_refname=${refname##refs/heads/}
+			;;
+		refs/remotes/*,commit)
+			# tracking branch
+			refname_type="tracking branch"
+			short_refname=${refname##refs/remotes/}
+			echo >&2 "*** Push-update of tracking branch, $refname"
+			echo >&2 "***  - no email generated."
+			return 1
+			;;
+		*)
+			# Anything else (is there anything else?)
+			echo >&2 "*** Unknown type of update to $refname ($rev_type)"
+			echo >&2 "***  - no email generated"
+			return 1
+			;;
+	esac
+
+	# Check if we've got anyone to send to
+	if [ -z "$recipients" ]; then
+		case "$refname_type" in
+			"annotated tag")
+				config_name="hooks.announcelist"
+				;;
+			*)
+				config_name="hooks.mailinglist"
+				;;
+		esac
+		echo >&2 "*** $config_name is not set so no email will be sent"
+		echo >&2 "*** for $refname update $oldrev->$newrev"
+		return 1
+	fi
+
+	return 0
+}
+
+#
+# Top level email generation function.  This calls the appropriate
+# body-generation routine after outputting the common header.
+#
+# Note this function doesn't actually generate any email output, that is
+# taken care of by the functions it calls:
+#  - generate_email_header
+#  - generate_create_XXXX_email
+#  - generate_update_XXXX_email
+#  - generate_delete_XXXX_email
+#  - generate_email_footer
+#
+# Note also that this function cannot 'exit' from the script; when this
+# function is running (in hook script mode), the send_mail() function
+# is already executing in another process, connected via a pipe, and
+# if this function exits without, whatever has been generated to that
+# point will be sent as an email... even if nothing has been generated.
+#
+generate_email()
+{
+	# Email parameters
+	# The email subject will contain the best description of the ref
+	# that we can build from the parameters
+	describe=$(git describe $rev 2>/dev/null)
+	if [ -z "$describe" ]; then
+		describe=$rev
+	fi
+
+	generate_email_header
+
+	# Call the correct body generation function
+	fn_name=general
+	case "$refname_type" in
+	"tracking branch"|branch)
+		fn_name=branch
+		;;
+	"annotated tag")
+		fn_name=atag
+		;;
+	esac
+
+	if [ -z "$maxlines" ]; then
+		generate_${change_type}_${fn_name}_email
+	else
+		generate_${change_type}_${fn_name}_email | limit_lines $maxlines
+	fi
+
+	generate_email_footer
+}
+
+generate_email_header()
+{
+	# --- Email (all stdout will be the email)
+	# Generate header
+	cat <<-EOF
+	To: $recipients
+	Subject: ${emailprefix}$projectdesc $refname_type $short_refname ${change_type}d. $describe
+	MIME-Version: 1.0
+	Content-Type: text/plain; charset=utf-8
+	Content-Transfer-Encoding: 8bit
+	X-Git-Refname: $refname
+	X-Git-Reftype: $refname_type
+	X-Git-Oldrev: $oldrev
+	X-Git-Newrev: $newrev
+	Auto-Submitted: auto-generated
+
+	This is an automated email from the git hooks/post-receive script. It was
+	generated because a ref change was pushed to the repository containing
+	the project "$projectdesc".
+
+	The $refname_type, $short_refname has been ${change_type}d
+	EOF
+}
+
+generate_email_footer()
+{
+	SPACE=" "
+	cat <<-EOF
+
+
+	hooks/post-receive
+	--${SPACE}
+	$projectdesc
+	EOF
+}
+
+# --------------- Branches
+
+#
+# Called for the creation of a branch
+#
+generate_create_branch_email()
+{
+	# This is a new branch and so oldrev is not valid
+	echo "        at  $newrev ($newrev_type)"
+	echo ""
+
+	echo $LOGBEGIN
+	show_new_revisions
+	echo $LOGEND
+}
+
+#
+# Called for the change of a pre-existing branch
+#
+generate_update_branch_email()
+{
+	# Consider this:
+	#   1 --- 2 --- O --- X --- 3 --- 4 --- N
+	#
+	# O is $oldrev for $refname
+	# N is $newrev for $refname
+	# X is a revision pointed to by some other ref, for which we may
+	#   assume that an email has already been generated.
+	# In this case we want to issue an email containing only revisions
+	# 3, 4, and N.  Given (almost) by
+	#
+	#  git rev-list N ^O --not --all
+	#
+	# The reason for the "almost", is that the "--not --all" will take
+	# precedence over the "N", and effectively will translate to
+	#
+	#  git rev-list N ^O ^X ^N
+	#
+	# So, we need to build up the list more carefully.  git rev-parse
+	# will generate a list of revs that may be fed into git rev-list.
+	# We can get it to make the "--not --all" part and then filter out
+	# the "^N" with:
+	#
+	#  git rev-parse --not --all | grep -v N
+	#
+	# Then, using the --stdin switch to git rev-list we have effectively
+	# manufactured
+	#
+	#  git rev-list N ^O ^X
+	#
+	# This leaves a problem when someone else updates the repository
+	# while this script is running.  Their new value of the ref we're
+	# working on would be included in the "--not --all" output; and as
+	# our $newrev would be an ancestor of that commit, it would exclude
+	# all of our commits.  What we really want is to exclude the current
+	# value of $refname from the --not list, rather than N itself.  So:
+	#
+	#  git rev-parse --not --all | grep -v $(git rev-parse $refname)
+	#
+	# Get's us to something pretty safe (apart from the small time
+	# between refname being read, and git rev-parse running - for that,
+	# I give up)
+	#
+	#
+	# Next problem, consider this:
+	#   * --- B --- * --- O ($oldrev)
+	#          \
+	#           * --- X --- * --- N ($newrev)
+	#
+	# That is to say, there is no guarantee that oldrev is a strict
+	# subset of newrev (it would have required a --force, but that's
+	# allowed).  So, we can't simply say rev-list $oldrev..$newrev.
+	# Instead we find the common base of the two revs and list from
+	# there.
+	#
+	# As above, we need to take into account the presence of X; if
+	# another branch is already in the repository and points at some of
+	# the revisions that we are about to output - we don't want them.
+	# The solution is as before: git rev-parse output filtered.
+	#
+	# Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
+	#
+	# Tags pushed into the repository generate nice shortlog emails that
+	# summarise the commits between them and the previous tag.  However,
+	# those emails don't include the full commit messages that we output
+	# for a branch update.  Therefore we still want to output revisions
+	# that have been output on a tag email.
+	#
+	# Luckily, git rev-parse includes just the tool.  Instead of using
+	# "--all" we use "--branches"; this has the added benefit that
+	# "remotes/" will be ignored as well.
+
+	# List all of the revisions that were removed by this update, in a
+	# fast-forward update, this list will be empty, because rev-list O
+	# ^N is empty.  For a non-fast-forward, O ^N is the list of removed
+	# revisions
+	fast_forward=""
+	rev=""
+	for rev in $(git rev-list $newrev..$oldrev)
+	do
+		revtype=$(git cat-file -t "$rev")
+		echo "  discards  $rev ($revtype)"
+	done
+	if [ -z "$rev" ]; then
+		fast_forward=1
+	fi
+
+	# List all the revisions from baserev to newrev in a kind of
+	# "table-of-contents"; note this list can include revisions that
+	# have already had notification emails and is present to show the
+	# full detail of the change from rolling back the old revision to
+	# the base revision and then forward to the new revision
+	for rev in $(git rev-list $oldrev..$newrev)
+	do
+		revtype=$(git cat-file -t "$rev")
+		echo "       via  $rev ($revtype)"
+	done
+
+	if [ "$fast_forward" ]; then
+		echo "      from  $oldrev ($oldrev_type)"
+	else
+		#  1. Existing revisions were removed.  In this case newrev
+		#     is a subset of oldrev - this is the reverse of a
+		#     fast-forward, a rewind
+		#  2. New revisions were added on top of an old revision,
+		#     this is a rewind and addition.
+
+		# (1) certainly happened, (2) possibly.  When (2) hasn't
+		# happened, we set a flag to indicate that no log printout
+		# is required.
+
+		echo ""
+
+		# Find the common ancestor of the old and new revisions and
+		# compare it with newrev
+		baserev=$(git merge-base $oldrev $newrev)
+		rewind_only=""
+		if [ "$baserev" = "$newrev" ]; then
+			echo "This update discarded existing revisions and left the branch pointing at"
+			echo "a previous point in the repository history."
+			echo ""
+			echo " * -- * -- N ($newrev)"
+			echo "            \\"
+			echo "             O -- O -- O ($oldrev)"
+			echo ""
+			echo "The removed revisions are not necessarily gone - if another reference"
+			echo "still refers to them they will stay in the repository."
+			rewind_only=1
+		else
+			echo "This update added new revisions after undoing existing revisions.  That is"
+			echo "to say, the old revision is not a strict subset of the new revision.  This"
+			echo "situation occurs when you --force push a change and generate a repository"
+			echo "containing something like this:"
+			echo ""
+			echo " * -- * -- B -- O -- O -- O ($oldrev)"
+			echo "            \\"
+			echo "             N -- N -- N ($newrev)"
+			echo ""
+			echo "When this happens we assume that you've already had alert emails for all"
+			echo "of the O revisions, and so we here report only the revisions in the N"
+			echo "branch from the common base, B."
+		fi
+	fi
+
+	echo ""
+	if [ -z "$rewind_only" ]; then
+		echo "Those revisions listed above that are new to this repository have"
+		echo "not appeared on any other notification email; so we list those"
+		echo "revisions in full, below."
+
+		echo ""
+		echo $LOGBEGIN
+		show_new_revisions
+
+		# XXX: Need a way of detecting whether git rev-list actually
+		# outputted anything, so that we can issue a "no new
+		# revisions added by this update" message
+
+		echo $LOGEND
+	else
+		echo "No new revisions were added by this update."
+	fi
+
+	# The diffstat is shown from the old revision to the new revision.
+	# This is to show the truth of what happened in this change.
+	# There's no point showing the stat from the base to the new
+	# revision because the base is effectively a random revision at this
+	# point - the user will be interested in what this revision changed
+	# - including the undoing of previous revisions in the case of
+	# non-fast-forward updates.
+	echo ""
+	echo "Summary of changes:"
+	git diff-tree $diffopts $oldrev..$newrev
+}
+
+#
+# Called for the deletion of a branch
+#
+generate_delete_branch_email()
+{
+	echo "       was  $oldrev"
+	echo ""
+	echo $LOGBEGIN
+	git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
+	echo $LOGEND
+}
+
+# --------------- Annotated tags
+
+#
+# Called for the creation of an annotated tag
+#
+generate_create_atag_email()
+{
+	echo "        at  $newrev ($newrev_type)"
+
+	generate_atag_email
+}
+
+#
+# Called for the update of an annotated tag (this is probably a rare event
+# and may not even be allowed)
+#
+generate_update_atag_email()
+{
+	echo "        to  $newrev ($newrev_type)"
+	echo "      from  $oldrev (which is now obsolete)"
+
+	generate_atag_email
+}
+
+#
+# Called when an annotated tag is created or changed
+#
+generate_atag_email()
+{
+	# Use git for-each-ref to pull out the individual fields from the
+	# tag
+	eval $(git for-each-ref --shell --format='
+	tagobject=%(*objectname)
+	tagtype=%(*objecttype)
+	tagger=%(taggername)
+	tagged=%(taggerdate)' $refname
+	)
+
+	echo "   tagging  $tagobject ($tagtype)"
+	case "$tagtype" in
+	commit)
+
+		# If the tagged object is a commit, then we assume this is a
+		# release, and so we calculate which tag this tag is
+		# replacing
+		prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null)
+
+		if [ -n "$prevtag" ]; then
+			echo "  replaces  $prevtag"
+		fi
+		;;
+	*)
+		echo "    length  $(git cat-file -s $tagobject) bytes"
+		;;
+	esac
+	echo " tagged by  $tagger"
+	echo "        on  $tagged"
+
+	echo ""
+	echo $LOGBEGIN
+
+	# Show the content of the tag message; this might contain a change
+	# log or release notes so is worth displaying.
+	git cat-file tag $newrev | sed -e '1,/^$/d'
+
+	echo ""
+	case "$tagtype" in
+	commit)
+		# Only commit tags make sense to have rev-list operations
+		# performed on them
+		if [ -n "$prevtag" ]; then
+			# Show changes since the previous release
+			git shortlog "$prevtag..$newrev"
+		else
+			# No previous tag, show all the changes since time
+			# began
+			git shortlog $newrev
+		fi
+		;;
+	*)
+		# XXX: Is there anything useful we can do for non-commit
+		# objects?
+		;;
+	esac
+
+	echo $LOGEND
+}
+
+#
+# Called for the deletion of an annotated tag
+#
+generate_delete_atag_email()
+{
+	echo "       was  $oldrev"
+	echo ""
+	echo $LOGBEGIN
+	git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
+	echo $LOGEND
+}
+
+# --------------- General references
+
+#
+# Called when any other type of reference is created (most likely a
+# non-annotated tag)
+#
+generate_create_general_email()
+{
+	echo "        at  $newrev ($newrev_type)"
+
+	generate_general_email
+}
+
+#
+# Called when any other type of reference is updated (most likely a
+# non-annotated tag)
+#
+generate_update_general_email()
+{
+	echo "        to  $newrev ($newrev_type)"
+	echo "      from  $oldrev"
+
+	generate_general_email
+}
+
+#
+# Called for creation or update of any other type of reference
+#
+generate_general_email()
+{
+	# Unannotated tags are more about marking a point than releasing a
+	# version; therefore we don't do the shortlog summary that we do for
+	# annotated tags above - we simply show that the point has been
+	# marked, and print the log message for the marked point for
+	# reference purposes
+	#
+	# Note this section also catches any other reference type (although
+	# there aren't any) and deals with them in the same way.
+
+	echo ""
+	if [ "$newrev_type" = "commit" ]; then
+		echo $LOGBEGIN
+		git diff-tree -s --always --encoding=UTF-8 --pretty=medium $newrev
+		echo $LOGEND
+	else
+		# What can we do here?  The tag marks an object that is not
+		# a commit, so there is no log for us to display.  It's
+		# probably not wise to output git cat-file as it could be a
+		# binary blob.  We'll just say how big it is
+		echo "$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long."
+	fi
+}
+
+#
+# Called for the deletion of any other type of reference
+#
+generate_delete_general_email()
+{
+	echo "       was  $oldrev"
+	echo ""
+	echo $LOGBEGIN
+	git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
+	echo $LOGEND
+}
+
+
+# --------------- Miscellaneous utilities
+
+#
+# Show new revisions as the user would like to see them in the email.
+#
+show_new_revisions()
+{
+	# This shows all log entries that are not already covered by
+	# another ref - i.e. commits that are now accessible from this
+	# ref that were previously not accessible
+	# (see generate_update_branch_email for the explanation of this
+	# command)
+
+	# Revision range passed to rev-list differs for new vs. updated
+	# branches.
+	if [ "$change_type" = create ]
+	then
+		# Show all revisions exclusive to this (new) branch.
+		revspec=$newrev
+	else
+		# Branch update; show revisions not part of $oldrev.
+		revspec=$oldrev..$newrev
+	fi
+
+	other_branches=$(git for-each-ref --format='%(refname)' refs/heads/ |
+	    grep -F -v $refname)
+	git rev-parse --not $other_branches |
+	if [ -z "$custom_showrev" ]
+	then
+		git rev-list --pretty --stdin $revspec
+	else
+		git rev-list --stdin $revspec |
+		while read onerev
+		do
+			eval $(printf "$custom_showrev" $onerev)
+		done
+	fi
+}
+
+
+limit_lines()
+{
+	lines=0
+	skipped=0
+	while IFS="" read -r line; do
+		lines=$((lines + 1))
+		if [ $lines -gt $1 ]; then
+			skipped=$((skipped + 1))
+		else
+			printf "%s\n" "$line"
+		fi
+	done
+	if [ $skipped -ne 0 ]; then
+		echo "... $skipped lines suppressed ..."
+	fi
+}
+
+
+send_mail()
+{
+	if [ -n "$envelopesender" ]; then
+		/usr/sbin/sendmail -t -f "$envelopesender"
+	else
+		/usr/sbin/sendmail -t
+	fi
+}
+
+# ---------------------------- main()
+
+# --- Constants
+LOGBEGIN="- Log -----------------------------------------------------------------"
+LOGEND="-----------------------------------------------------------------------"
+
+# --- Config
+# Set GIT_DIR either from the working directory, or from the environment
+# variable.
+GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
+if [ -z "$GIT_DIR" ]; then
+	echo >&2 "fatal: post-receive: GIT_DIR not set"
+	exit 1
+fi
+
+projectdesc=$(sed -ne '1p' "$GIT_DIR/description" 2>/dev/null)
+# Check if the description is unchanged from it's default, and shorten it to
+# a more manageable length if it is
+if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null
+then
+	projectdesc="UNNAMED PROJECT"
+fi
+
+recipients=$(git config hooks.mailinglist)
+announcerecipients=$(git config hooks.announcelist)
+envelopesender=$(git config hooks.envelopesender)
+emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
+custom_showrev=$(git config hooks.showrev)
+maxlines=$(git config hooks.emailmaxlines)
+diffopts=$(git config hooks.diffopts)
+: ${diffopts:="--stat --summary --find-copies-harder"}
+
+# --- Main loop
+# Allow dual mode: run from the command line just like the update hook, or
+# if no arguments are given then run as a hook script
+if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
+	# Output to the terminal in command line mode - if someone wanted to
+	# resend an email; they could redirect the output to sendmail
+	# themselves
+	prep_for_email $2 $3 $1 && PAGER= generate_email
+else
+	while read oldrev newrev refname
+	do
+		prep_for_email $oldrev $newrev $refname || continue
+		generate_email $maxlines | send_mail
+	done
+fi
diff --git a/contrib/hooks/pre-auto-gc-battery b/contrib/hooks/pre-auto-gc-battery
new file mode 100755
index 000000000000..7ba78c4dff68
--- /dev/null
+++ b/contrib/hooks/pre-auto-gc-battery
@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# An example hook script to verify if you are on battery, in case you
+# are running Linux or OS X. Called by git-gc --auto with no arguments.
+# The hook should exit with non-zero status after issuing an appropriate
+# message if it wants to stop the auto repacking.
+#
+# This hook is stored in the contrib/hooks directory. Your distribution
+# may have put this somewhere else. If you want to use this hook, you
+# should make this script executable then link to it in the repository
+# you would like to use it in.
+#
+# For example, if the hook is stored in
+# /usr/share/git-core/contrib/hooks/pre-auto-gc-battery:
+#
+# cd /path/to/your/repository.git
+# ln -sf /usr/share/git-core/contrib/hooks/pre-auto-gc-battery \
+#	hooks/pre-auto-gc
+
+if test -x /sbin/on_ac_power && (/sbin/on_ac_power;test $? -ne 1)
+then
+	exit 0
+elif test "$(cat /sys/class/power_supply/AC/online 2>/dev/null)" = 1
+then
+	exit 0
+elif grep -q 'on-line' /proc/acpi/ac_adapter/AC/state 2>/dev/null
+then
+	exit 0
+elif grep -q '0x01$' /proc/apm 2>/dev/null
+then
+	exit 0
+elif grep -q "AC Power \+: 1" /proc/pmu/info 2>/dev/null
+then
+	exit 0
+elif test -x /usr/bin/pmset && /usr/bin/pmset -g batt |
+	grep -q "drawing from 'AC Power'"
+then
+	exit 0
+fi
+
+echo "Auto packing deferred; not on AC"
+exit 1
diff --git a/contrib/hooks/setgitperms.perl b/contrib/hooks/setgitperms.perl
new file mode 100755
index 000000000000..2770a1b1d205
--- /dev/null
+++ b/contrib/hooks/setgitperms.perl
@@ -0,0 +1,214 @@
+#!/usr/bin/perl
+#
+# Copyright (c) 2006 Josh England
+#
+# This script can be used to save/restore full permissions and ownership data
+# within a git working tree.
+#
+# To save permissions/ownership data, place this script in your .git/hooks
+# directory and enable a `pre-commit` hook with the following lines:
+#      #!/bin/sh
+#     SUBDIRECTORY_OK=1 . git-sh-setup
+#     $GIT_DIR/hooks/setgitperms.perl -r
+#
+# To restore permissions/ownership data, place this script in your .git/hooks
+# directory and enable a `post-merge` and `post-checkout` hook with the
+# following lines:
+#      #!/bin/sh
+#     SUBDIRECTORY_OK=1 . git-sh-setup
+#     $GIT_DIR/hooks/setgitperms.perl -w
+#
+use strict;
+use Getopt::Long;
+use File::Find;
+use File::Basename;
+
+my $usage =
+"usage: setgitperms.perl [OPTION]... <--read|--write>
+This program uses a file `.gitmeta` to store/restore permissions and uid/gid
+info for all files/dirs tracked by git in the repository.
+
+---------------------------------Read Mode-------------------------------------
+-r,  --read         Reads perms/etc from working dir into a .gitmeta file
+-s,  --stdout       Output to stdout instead of .gitmeta
+-d,  --diff         Show unified diff of perms file (XOR with --stdout)
+
+---------------------------------Write Mode------------------------------------
+-w,  --write        Modify perms/etc in working dir to match the .gitmeta file
+-v,  --verbose      Be verbose
+
+\n";
+
+my ($stdout, $showdiff, $verbose, $read_mode, $write_mode);
+
+if ((@ARGV < 0) || !GetOptions(
+			       "stdout",         \$stdout,
+			       "diff",           \$showdiff,
+			       "read",           \$read_mode,
+			       "write",          \$write_mode,
+			       "verbose",        \$verbose,
+			      )) { die $usage; }
+die $usage unless ($read_mode xor $write_mode);
+
+my $topdir = `git rev-parse --show-cdup` or die "\n"; chomp $topdir;
+my $gitdir = $topdir . '.git';
+my $gitmeta = $topdir . '.gitmeta';
+
+if ($write_mode) {
+    # Update the working dir permissions/ownership based on data from .gitmeta
+    open (IN, "<$gitmeta") or die "Could not open $gitmeta for reading: $!\n";
+    while (defined ($_ = )) {
+	chomp;
+	if (/^(.*)  mode=(\S+)\s+uid=(\d+)\s+gid=(\d+)/) {
+	    # Compare recorded perms to actual perms in the working dir
+	    my ($path, $mode, $uid, $gid) = ($1, $2, $3, $4);
+	    my $fullpath = $topdir . $path;
+	    my (undef,undef,$wmode,undef,$wuid,$wgid) = lstat($fullpath);
+	    $wmode = sprintf "%04o", $wmode & 07777;
+	    if ($mode ne $wmode) {
+		$verbose && print "Updating permissions on $path: old=$wmode, new=$mode\n";
+		chmod oct($mode), $fullpath;
+	    }
+	    if ($uid != $wuid || $gid != $wgid) {
+		if ($verbose) {
+		    # Print out user/group names instead of uid/gid
+		    my $pwname  = getpwuid($uid);
+		    my $grpname  = getgrgid($gid);
+		    my $wpwname  = getpwuid($wuid);
+		    my $wgrpname  = getgrgid($wgid);
+		    $pwname = $uid if !defined $pwname;
+		    $grpname = $gid if !defined $grpname;
+		    $wpwname = $wuid if !defined $wpwname;
+		    $wgrpname = $wgid if !defined $wgrpname;
+
+		    print "Updating uid/gid on $path: old=$wpwname/$wgrpname, new=$pwname/$grpname\n";
+		}
+		chown $uid, $gid, $fullpath;
+	    }
+	}
+	else {
+	    warn "Invalid input format in $gitmeta:\n\t$_\n";
+	}
+    }
+    close IN;
+}
+elsif ($read_mode) {
+    # Handle merge conflicts in the .gitperms file
+    if (-e "$gitdir/MERGE_MSG") {
+	if (`grep ====== $gitmeta`) {
+	    # Conflict not resolved -- abort the commit
+	    print "PERMISSIONS/OWNERSHIP CONFLICT\n";
+	    print "    Resolve the conflict in the $gitmeta file and then run\n";
+	    print "    `.git/hooks/setgitperms.perl --write` to reconcile.\n";
+	    exit 1;
+	}
+	elsif (`grep $gitmeta $gitdir/MERGE_MSG`) {
+	    # A conflict in .gitmeta has been manually resolved. Verify that
+	    # the working dir perms matches the current .gitmeta perms for
+	    # each file/dir that conflicted.
+	    # This is here because a `setgitperms.perl --write` was not
+	    # performed due to a merge conflict, so permissions/ownership
+	    # may not be consistent with the manually merged .gitmeta file.
+	    my @conflict_diff = `git show \$(cat $gitdir/MERGE_HEAD)`;
+	    my @conflict_files;
+	    my $metadiff = 0;
+
+	    # Build a list of files that conflicted from the .gitmeta diff
+	    foreach my $line (@conflict_diff) {
+		if ($line =~ m|^diff --git a/$gitmeta b/$gitmeta|) {
+		    $metadiff = 1;
+		}
+		elsif ($line =~ /^diff --git/) {
+		    $metadiff = 0;
+		}
+		elsif ($metadiff && $line =~ /^\+(.*)  mode=/) {
+		    push @conflict_files, $1;
+		}
+	    }
+
+	    # Verify that each conflict file now has permissions consistent
+	    # with the .gitmeta file
+	    foreach my $file (@conflict_files) {
+		my $absfile = $topdir . $file;
+		my $gm_entry = `grep "^$file  mode=" $gitmeta`;
+		if ($gm_entry =~ /mode=(\d+)  uid=(\d+)  gid=(\d+)/) {
+		    my ($gm_mode, $gm_uid, $gm_gid) = ($1, $2, $3);
+		    my (undef,undef,$mode,undef,$uid,$gid) = lstat("$absfile");
+		    $mode = sprintf("%04o", $mode & 07777);
+		    if (($gm_mode ne $mode) || ($gm_uid != $uid)
+			|| ($gm_gid != $gid)) {
+			print "PERMISSIONS/OWNERSHIP CONFLICT\n";
+			print "    Mismatch found for file: $file\n";
+			print "    Run `.git/hooks/setgitperms.perl --write` to reconcile.\n";
+			exit 1;
+		    }
+		}
+		else {
+		    print "Warning! Permissions/ownership no longer being tracked for file: $file\n";
+		}
+	    }
+	}
+    }
+
+    # No merge conflicts -- write out perms/ownership data to .gitmeta file
+    unless ($stdout) {
+	open (OUT, ">$gitmeta.tmp") or die "Could not open $gitmeta.tmp for writing: $!\n";
+    }
+
+    my @files = `git ls-files`;
+    my %dirs;
+
+    foreach my $path (@files) {
+	chomp $path;
+	# We have to manually add stats for parent directories
+	my $parent = dirname($path);
+	while (!exists $dirs{$parent}) {
+	    $dirs{$parent} = 1;
+	    next if $parent eq '.';
+	    printstats($parent);
+	    $parent = dirname($parent);
+	}
+	# Now the git-tracked file
+	printstats($path);
+    }
+
+    # diff the temporary metadata file to see if anything has changed
+    # If no metadata has changed, don't overwrite the real file
+    # This is just so `git commit -a` doesn't try to commit a bogus update
+    unless ($stdout) {
+	if (! -e $gitmeta) {
+	    rename "$gitmeta.tmp", $gitmeta;
+	}
+	else {
+	    my $diff = `diff -U 0 $gitmeta $gitmeta.tmp`;
+	    if ($diff ne '') {
+		rename "$gitmeta.tmp", $gitmeta;
+	    }
+	    else {
+		unlink "$gitmeta.tmp";
+	    }
+	    if ($showdiff) {
+		print $diff;
+	    }
+	}
+	close OUT;
+    }
+    # Make sure the .gitmeta file is tracked
+    system("git add $gitmeta");
+}
+
+
+sub printstats {
+    my $path = $_[0];
+    $path =~ s/@/\@/g;
+    my (undef,undef,$mode,undef,$uid,$gid) = lstat($path);
+    $path =~ s/%/\%/g;
+    if ($stdout) {
+	print $path;
+	printf "  mode=%04o  uid=$uid  gid=$gid\n", $mode & 07777;
+    }
+    else {
+	print OUT $path;
+	printf OUT "  mode=%04o  uid=$uid  gid=$gid\n", $mode & 07777;
+    }
+}
diff --git a/contrib/hooks/update-paranoid b/contrib/hooks/update-paranoid
new file mode 100755
index 000000000000..d18b317b2f01
--- /dev/null
+++ b/contrib/hooks/update-paranoid
@@ -0,0 +1,421 @@
+#!/usr/bin/perl
+
+use strict;
+use File::Spec;
+
+$ENV{PATH}     = '/opt/git/bin';
+my $acl_git    = '/vcs/acls.git';
+my $acl_branch = 'refs/heads/master';
+my $debug      = 0;
+
+=doc
+Invoked as: update refname old-sha1 new-sha1
+
+This script is run by git-receive-pack once for each ref that the
+client is trying to modify.  If we exit with a non-zero exit value
+then the update for that particular ref is denied, but updates for
+other refs in the same run of receive-pack may still be allowed.
+
+We are run after the objects have been uploaded, but before the
+ref is actually modified.  We take advantage of that fact when we
+look for "new" commits and tags (the new objects won't show up in
+`rev-list --all`).
+
+This script loads and parses the content of the config file
+"users/$this_user.acl" from the $acl_branch commit of $acl_git ODB.
+The acl file is a git-config style file, but uses a slightly more
+restricted syntax as the Perl parser contained within this script
+is not nearly as permissive as git-config.
+
+Example:
+
+  [user]
+    committer = John Doe 
+    committer = John R. Doe 
+
+  [repository "acls"]
+    allow = heads/master
+    allow = CDUR for heads/jd/
+    allow = C    for ^tags/v\\d+$
+
+For all new commit or tag objects the committer (or tagger) line
+within the object must exactly match one of the user.committer
+values listed in the acl file ("HEAD:users/$this_user.acl").
+
+For a branch to be modified an allow line within the matching
+repository section must be matched for both the refname and the
+opcode.
+
+Repository sections are matched on the basename of the repository
+(after removing the .git suffix).
+
+The opcode abbrevations are:
+
+  C: create new ref
+  D: delete existing ref
+  U: fast-forward existing ref (no commit loss)
+  R: rewind/rebase existing ref (commit loss)
+
+if no opcodes are listed before the "for" keyword then "U" (for
+fast-forward update only) is assumed as this is the most common
+usage.
+
+Refnames are matched by always assuming a prefix of "refs/".
+This hook forbids pushing or deleting anything not under "refs/".
+
+Refnames that start with ^ are Perl regular expressions, and the ^
+is kept as part of the regexp.  \\ is needed to get just one \, so
+\\d expands to \d in Perl.  The 3rd allow line above is an example.
+
+Refnames that don't start with ^ but that end with / are prefix
+matches (2nd allow line above); all other refnames are strict
+equality matches (1st allow line).
+
+Anything pushed to "heads/" (ok, really "refs/heads/") must be
+a commit.  Tags are not permitted here.
+
+Anything pushed to "tags/" (err, really "refs/tags/") must be an
+annotated tag.  Commits, blobs, trees, etc. are not permitted here.
+Annotated tag signatures aren't checked, nor are they required.
+
+The special subrepository of 'info/new-commit-check' can
+be created and used to allow users to push new commits and
+tags from another local repository to this one, even if they
+aren't the committer/tagger of those objects.  In a nut shell
+the info/new-commit-check directory is a Git repository whose
+objects/info/alternates file lists this repository and all other
+possible sources, and whose refs subdirectory contains symlinks
+to this repository's refs subdirectory, and to all other possible
+sources refs subdirectories.  Yes, this means that you cannot
+use packed-refs in those repositories as they won't be resolved
+correctly.
+
+=cut
+
+my $git_dir = $ENV{GIT_DIR};
+my $new_commit_check = "$git_dir/info/new-commit-check";
+my $ref = $ARGV[0];
+my $old = $ARGV[1];
+my $new = $ARGV[2];
+my $new_type;
+my ($this_user) = getpwuid $<; # REAL_USER_ID
+my $repository_name;
+my %user_committer;
+my @allow_rules;
+my @path_rules;
+my %diff_cache;
+
+sub deny ($) {
+	print STDERR "-Deny-    $_[0]\n" if $debug;
+	print STDERR "\ndenied: $_[0]\n\n";
+	exit 1;
+}
+
+sub grant ($) {
+	print STDERR "-Grant-   $_[0]\n" if $debug;
+	exit 0;
+}
+
+sub info ($) {
+	print STDERR "-Info-    $_[0]\n" if $debug;
+}
+
+sub git_value (@) {
+	open(T,'-|','git',@_); local $_ = ; chop; close T; $_;
+}
+
+sub match_string ($$) {
+	my ($acl_n, $ref) = @_;
+	   ($acl_n eq $ref)
+	|| ($acl_n =~ m,/$, && substr($ref,0,length $acl_n) eq $acl_n)
+	|| ($acl_n =~ m,^\^, && $ref =~ m:$acl_n:);
+}
+
+sub parse_config ($$$$) {
+	my $data = shift;
+	local $ENV{GIT_DIR} = shift;
+	my $br = shift;
+	my $fn = shift;
+	return unless git_value('rev-list','--max-count=1',$br,'--',$fn);
+	info "Loading $br:$fn";
+	open(I,'-|','git','cat-file','blob',"$br:$fn");
+	my $section = '';
+	while () {
+		chomp;
+		if (/^\s*$/ || /^\s*#/) {
+		} elsif (/^\[([a-z]+)\]$/i) {
+			$section = lc $1;
+		} elsif (/^\[([a-z]+)\s+"(.*)"\]$/i) {
+			$section = join('.',lc $1,$2);
+		} elsif (/^\s*([a-z][a-z0-9]+)\s*=\s*(.*?)\s*$/i) {
+			push @{$data->{join('.',$section,lc $1)}}, $2;
+		} else {
+			deny "bad config file line $. in $br:$fn";
+		}
+	}
+	close I;
+}
+
+sub all_new_committers () {
+	local $ENV{GIT_DIR} = $git_dir;
+	$ENV{GIT_DIR} = $new_commit_check if -d $new_commit_check;
+
+	info "Getting committers of new commits.";
+	my %used;
+	open(T,'-|','git','rev-list','--pretty=raw',$new,'--not','--all');
+	while () {
+		next unless s/^committer //;
+		chop;
+		s/>.*$/>/;
+		info "Found $_." unless $used{$_}++;
+	}
+	close T;
+	info "No new commits." unless %used;
+	keys %used;
+}
+
+sub all_new_taggers () {
+	my %exists;
+	open(T,'-|','git','for-each-ref','--format=%(objectname)','refs/tags');
+	while () {
+		chop;
+		$exists{$_} = 1;
+	}
+	close T;
+
+	info "Getting taggers of new tags.";
+	my %used;
+	my $obj = $new;
+	my $obj_type = $new_type;
+	while ($obj_type eq 'tag') {
+		last if $exists{$obj};
+		$obj_type = '';
+		open(T,'-|','git','cat-file','tag',$obj);
+		while () {
+			chop;
+			if (/^object ([a-z0-9]{40})$/) {
+				$obj = $1;
+			} elsif (/^type (.+)$/) {
+				$obj_type = $1;
+			} elsif (s/^tagger //) {
+				s/>.*$/>/;
+				info "Found $_." unless $used{$_}++;
+				last;
+			}
+		}
+		close T;
+	}
+	info "No new tags." unless %used;
+	keys %used;
+}
+
+sub check_committers (@) {
+	my @bad;
+	foreach (@_) { push @bad, $_ unless $user_committer{$_}; }
+	if (@bad) {
+		print STDERR "\n";
+		print STDERR "You are not $_.\n" foreach (sort @bad);
+		deny "You cannot push changes not committed by you.";
+	}
+}
+
+sub load_diff ($) {
+	my $base = shift;
+	my $d = $diff_cache{$base};
+	unless ($d) {
+		local $/ = "\0";
+		my %this_diff;
+		if ($base =~ /^0{40}$/) {
+			# Don't load the diff at all; we are making the
+			# branch and have no base to compare to in this
+			# case.  A file level ACL makes no sense in this
+			# context.  Having an empty diff will allow the
+			# branch creation.
+			#
+		} else {
+			open(T,'-|','git','diff-tree',
+				'-r','--name-status','-z',
+				$base,$new) or return undef;
+			while () {
+				my $op = $_;
+				chop $op;
+
+				my $path = ;
+				chop $path;
+
+				$this_diff{$path} = $op;
+			}
+			close T or return undef;
+		}
+		$d = \%this_diff;
+		$diff_cache{$base} = $d;
+	}
+	return $d;
+}
+
+deny "No GIT_DIR inherited from caller" unless $git_dir;
+deny "Need a ref name" unless $ref;
+deny "Refusing funny ref $ref" unless $ref =~ s,^refs/,,;
+deny "Bad old value $old" unless $old =~ /^[a-z0-9]{40}$/;
+deny "Bad new value $new" unless $new =~ /^[a-z0-9]{40}$/;
+deny "Cannot determine who you are." unless $this_user;
+grant "No change requested." if $old eq $new;
+
+$repository_name = File::Spec->rel2abs($git_dir);
+$repository_name =~ m,/([^/]+)(?:\.git|/\.git)$,;
+$repository_name = $1;
+info "Updating in '$repository_name'.";
+
+my $op;
+if    ($old =~ /^0{40}$/) { $op = 'C'; }
+elsif ($new =~ /^0{40}$/) { $op = 'D'; }
+else                      { $op = 'R'; }
+
+# This is really an update (fast-forward) if the
+# merge base of $old and $new is $old.
+#
+$op = 'U' if ($op eq 'R'
+	&& $ref =~ m,^heads/,
+	&& $old eq git_value('merge-base',$old,$new));
+
+# Load the user's ACL file. Expand groups (user.memberof) one level.
+{
+	my %data = ('user.committer' => []);
+	parse_config(\%data,$acl_git,$acl_branch,"external/$repository_name.acl");
+
+	%data = (
+		'user.committer' => $data{'user.committer'},
+		'user.memberof' => [],
+	);
+	parse_config(\%data,$acl_git,$acl_branch,"users/$this_user.acl");
+
+	%user_committer = map {$_ => $_} @{$data{'user.committer'}};
+	my $rule_key = "repository.$repository_name.allow";
+	my $rules = $data{$rule_key} || [];
+
+	foreach my $group (@{$data{'user.memberof'}}) {
+		my %g;
+		parse_config(\%g,$acl_git,$acl_branch,"groups/$group.acl");
+		my $group_rules = $g{$rule_key};
+		push @$rules, @$group_rules if $group_rules;
+	}
+
+RULE:
+	foreach (@$rules) {
+		while (/\${user\.([a-z][a-zA-Z0-9]+)}/) {
+			my $k = lc $1;
+			my $v = $data{"user.$k"};
+			next RULE unless defined $v;
+			next RULE if @$v != 1;
+			next RULE unless defined $v->[0];
+			s/\${user\.$k}/$v->[0]/g;
+		}
+
+		if (/^([AMD ]+)\s+of\s+([^\s]+)\s+for\s+([^\s]+)\s+diff\s+([^\s]+)$/) {
+			my ($ops, $pth, $ref, $bst) = ($1, $2, $3, $4);
+			$ops =~ s/ //g;
+			$pth =~ s/\\\\/\\/g;
+			$ref =~ s/\\\\/\\/g;
+			push @path_rules, [$ops, $pth, $ref, $bst];
+		} elsif (/^([AMD ]+)\s+of\s+([^\s]+)\s+for\s+([^\s]+)$/) {
+			my ($ops, $pth, $ref) = ($1, $2, $3);
+			$ops =~ s/ //g;
+			$pth =~ s/\\\\/\\/g;
+			$ref =~ s/\\\\/\\/g;
+			push @path_rules, [$ops, $pth, $ref, $old];
+		} elsif (/^([CDRU ]+)\s+for\s+([^\s]+)$/) {
+			my $ops = $1;
+			my $ref = $2;
+			$ops =~ s/ //g;
+			$ref =~ s/\\\\/\\/g;
+			push @allow_rules, [$ops, $ref];
+		} elsif (/^for\s+([^\s]+)$/) {
+			# Mentioned, but nothing granted?
+		} elsif (/^[^\s]+$/) {
+			s/\\\\/\\/g;
+			push @allow_rules, ['U', $_];
+		}
+	}
+}
+
+if ($op ne 'D') {
+	$new_type = git_value('cat-file','-t',$new);
+
+	if ($ref =~ m,^heads/,) {
+		deny "$ref must be a commit." unless $new_type eq 'commit';
+	} elsif ($ref =~ m,^tags/,) {
+		deny "$ref must be an annotated tag." unless $new_type eq 'tag';
+	}
+
+	check_committers (all_new_committers);
+	check_committers (all_new_taggers) if $new_type eq 'tag';
+}
+
+info "$this_user wants $op for $ref";
+foreach my $acl_entry (@allow_rules) {
+	my ($acl_ops, $acl_n) = @$acl_entry;
+	next unless $acl_ops =~ /^[CDRU]+$/; # Uhh.... shouldn't happen.
+	next unless $acl_n;
+	next unless $op =~ /^[$acl_ops]$/;
+	next unless match_string $acl_n, $ref;
+
+	# Don't test path rules on branch deletes.
+	#
+	grant "Allowed by: $acl_ops for $acl_n" if $op eq 'D';
+
+	# Aggregate matching path rules; allow if there aren't
+	# any matching this ref.
+	#
+	my %pr;
+	foreach my $p_entry (@path_rules) {
+		my ($p_ops, $p_n, $p_ref, $p_bst) = @$p_entry;
+		next unless $p_ref;
+		push @{$pr{$p_bst}}, $p_entry if match_string $p_ref, $ref;
+	}
+	grant "Allowed by: $acl_ops for $acl_n" unless %pr;
+
+	# Allow only if all changes against a single base are
+	# allowed by file path rules.
+	#
+	my @bad;
+	foreach my $p_bst (keys %pr) {
+		my $diff_ref = load_diff $p_bst;
+		deny "Cannot difference trees." unless ref $diff_ref;
+
+		my %fd = %$diff_ref;
+		foreach my $p_entry (@{$pr{$p_bst}}) {
+			my ($p_ops, $p_n, $p_ref, $p_bst) = @$p_entry;
+			next unless $p_ops =~ /^[AMD]+$/;
+			next unless $p_n;
+
+			foreach my $f_n (keys %fd) {
+				my $f_op = $fd{$f_n};
+				next unless $f_op;
+				next unless $f_op =~ /^[$p_ops]$/;
+				delete $fd{$f_n} if match_string $p_n, $f_n;
+			}
+			last unless %fd;
+		}
+
+		if (%fd) {
+			push @bad, [$p_bst, \%fd];
+		} else {
+			# All changes relative to $p_bst were allowed.
+			#
+			grant "Allowed by: $acl_ops for $acl_n diff $p_bst";
+		}
+	}
+
+	foreach my $bad_ref (@bad) {
+		my ($p_bst, $fd) = @$bad_ref;
+		print STDERR "\n";
+		print STDERR "Not allowed to make the following changes:\n";
+		print STDERR "(base: $p_bst)\n";
+		foreach my $f_n (sort keys %$fd) {
+			print STDERR "  $fd->{$f_n} $f_n\n";
+		}
+	}
+	deny "You are not permitted to $op $ref";
+}
+close A;
+deny "You are not permitted to $op $ref";
-- 
cgit 1.4.1