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diff --git a/Documentation/RelNotes/2.11.0.txt b/Documentation/RelNotes/2.11.0.txt new file mode 100644 index 000000000000..b7b7dd361ef0 --- /dev/null +++ b/Documentation/RelNotes/2.11.0.txt @@ -0,0 +1,593 @@ +Git 2.11 Release Notes +====================== + +Backward compatibility notes. + + * An empty string used as a pathspec element has always meant + 'everything matches', but it is too easy to write a script that + finds a path to remove in $path and run 'git rm "$paht"' by + mistake (when the user meant to give "$path"), which ends up + removing everything. This release starts warning about the + use of an empty string that is used for 'everything matches' and + asks users to use a more explicit '.' for that instead. + + The hope is that existing users will not mind this change, and + eventually the warning can be turned into a hard error, upgrading + the deprecation into removal of this (mis)feature. + + * The historical argument order "git merge <msg> HEAD <commit>..." + has been deprecated for quite some time, and will be removed in the + next release (not this one). + + * The default abbreviation length, which has historically been 7, now + scales as the repository grows, using the approximate number of + objects in the repository and a bit of math around the birthday + paradox. The logic suggests to use 12 hexdigits for the Linux + kernel, and 9 to 10 for Git itself. + + +Updates since v2.10 +------------------- + +UI, Workflows & Features + + * Comes with new version of git-gui, now at its 0.21.0 tag. + + * "git format-patch --cover-letter HEAD^" to format a single patch + with a separate cover letter now numbers the output as [PATCH 0/1] + and [PATCH 1/1] by default. + + * An incoming "git push" that attempts to push too many bytes can now + be rejected by setting a new configuration variable at the receiving + end. + + * "git nosuchcommand --help" said "No manual entry for gitnosuchcommand", + which was not intuitive, given that "git nosuchcommand" said "git: + 'nosuchcommand' is not a git command". + + * "git clone --recurse-submodules --reference $path $URL" is a way to + reduce network transfer cost by borrowing objects in an existing + $path repository when cloning the superproject from $URL; it + learned to also peek into $path for presence of corresponding + repositories of submodules and borrow objects from there when able. + + * The "git diff --submodule={short,log}" mechanism has been enhanced + to allow "--submodule=diff" to show the patch between the submodule + commits bound to the superproject. + + * Even though "git hash-objects", which is a tool to take an + on-filesystem data stream and put it into the Git object store, + can perform "outside-world-to-Git" conversions (e.g. + end-of-line conversions and application of the clean-filter), and + it has had this feature on by default from very early days, its reverse + operation "git cat-file", which takes an object from the Git object + store and externalizes it for consumption by the outside world, + lacked an equivalent mechanism to run the "Git-to-outside-world" + conversion. The command learned the "--filters" option to do so. + + * Output from "git diff" can be made easier to read by intelligently selecting + which lines are common and which lines are added/deleted + when the lines before and after the changed section + are the same. A command line option (--indent-heuristic) and a + configuration variable (diff.indentHeuristic) are added to help with the + experiment to find good heuristics. + + * In some projects, it is common to use "[RFC PATCH]" as the subject + prefix for a patch meant for discussion rather than application. A + new format-patch option "--rfc" is a short-hand for "--subject-prefix=RFC PATCH" + to help the participants of such projects. + + * "git add --chmod={+,-}x <pathspec>" only changed the + executable bit for paths that are either new or modified. This has + been corrected to change the executable bit for all paths that match + the given pathspec. + + * When "git format-patch --stdout" output is placed as an in-body + header and it uses RFC2822 header folding, "git am" fails to + put the header line back into a single logical line. The + underlying "git mailinfo" was taught to handle this properly. + + * "gitweb" can spawn "highlight" to show blob contents with + (programming) language-specific syntax highlighting, but only + when the language is known. "highlight" can however be told + to guess the language itself by giving it "--force" option, which + has been enabled. + + * "git gui" l10n to Portuguese. + + * When given an abbreviated object name that is not (or more + realistically, "no longer") unique, we gave a fatal error + "ambiguous argument". This error is now accompanied by a hint that + lists the objects beginning with the given prefix. During the + course of development of this new feature, numerous minor bugs were + uncovered and corrected, the most notable one of which is that we + gave "short SHA1 xxxx is ambiguous." twice without good reason. + + * "git log rev^..rev" is an often-used revision range specification + to show what was done on a side branch merged at rev. This has + gained a short-hand "rev^-1". In general "rev^-$n" is the same as + "^rev^$n rev", i.e. what has happened on other branches while the + history leading to nth parent was looking the other way. + + * In recent versions of cURL, GSSAPI credential delegation is + disabled by default due to CVE-2011-2192; introduce a http.delegation + configuration variable to selectively allow enabling this. + (merge 26a7b23429 ps/http-gssapi-cred-delegation later to maint). + + * "git mergetool" learned to honor "-O<orderfile>" to control the + order of paths to present to the end user. + + * "git diff/log --ws-error-highlight=<kind>" lacked the corresponding + configuration variable (diff.wsErrorHighlight) to set it by default. + + * "git ls-files" learned the "--recurse-submodules" option + to get a listing of tracked files across submodules (i.e. this + only works with the "--cached" option, not for listing untracked or + ignored files). This would be a useful tool to sit on the upstream + side of a pipe that is read with xargs to work on all working tree + files from the top-level superproject. + + * A new credential helper that talks via "libsecret" with + implementations of XDG Secret Service API has been added to + contrib/credential/. + + * The GPG verification status shown by the "%G?" pretty format specifier + was not rich enough to differentiate a signature made by an expired + key, a signature made by a revoked key, etc. New output letters + have been assigned to express them. + + * In addition to purely abbreviated commit object names, "gitweb" + learned to turn "git describe" output (e.g. v2.9.3-599-g2376d31787) + into clickable links in its output. + + * "git commit" created an empty commit when invoked with an index + consisting solely of intend-to-add paths (added with "git add -N"). + It now requires the "--allow-empty" option to create such a commit. + The same logic prevented "git status" from showing such paths as "new files" in the + "Changes not staged for commit" section. + + * The smudge/clean filter API spawns an external process + to filter the contents of each path that has a filter defined. A + new type of "process" filter API has been added to allow the first + request to run the filter for a path to spawn a single process, and + all filtering is served by this single process for multiple + paths, reducing the process creation overhead. + + * The user always has to say "stash@{$N}" when naming a single + element in the default location of the stash, i.e. reflogs in + refs/stash. The "git stash" command learned to accept "git stash + apply 4" as a short-hand for "git stash apply stash@{4}". + + +Performance, Internal Implementation, Development Support etc. + + * The delta-base-cache mechanism has been a key to the performance in + a repository with a tightly packed packfile, but it did not scale + well even with a larger value of core.deltaBaseCacheLimit. + + * Enhance "git status --porcelain" output by collecting more data on + the state of the index and the working tree files, which may + further be used to teach git-prompt (in contrib/) to make fewer + calls to git. + + * Extract a small helper out of the function that reads the authors + script file "git am" internally uses. + (merge a77598e jc/am-read-author-file later to maint). + + * Lift calls to exit(2) and die() higher in the callchain in + sequencer.c files so that more helper functions in it can be used + by callers that want to handle error conditions themselves. + + * "git am" has been taught to make an internal call to "git apply"'s + innards without spawning the latter as a separate process. + + * The ref-store abstraction was introduced to the refs API so that we + can plug in different backends to store references. + + * The "unsigned char sha1[20]" to "struct object_id" conversion + continues. Notable changes in this round includes that ce->sha1, + i.e. the object name recorded in the cache_entry, turns into an + object_id. + + * JGit can show a fake ref "capabilities^{}" to "git fetch" when it + does not advertise any refs, but "git fetch" was not prepared to + see such an advertisement. When the other side disconnects without + giving any ref advertisement, we used to say "there may not be a + repository at that URL", but we may have seen other advertisements + like "shallow" and ".have" in which case we definitely know that a + repository is there. The code to detect this case has also been + updated. + + * Some codepaths in "git pack-objects" were not ready to use an + existing pack bitmap; now they are and as a result they have + become faster. + + * The codepath in "git fsck" to detect malformed tree objects has + been updated not to die but keep going after detecting them. + + * We call "qsort(array, nelem, sizeof(array[0]), fn)", and most of + the time third parameter is redundant. A new QSORT() macro lets us + omit it. + + * "git pack-objects" in a repository with many packfiles used to + spend a lot of time looking for/at objects in them; the accesses to + the packfiles are now optimized by checking the most-recently-used + packfile first. + (merge c9af708b1a jk/pack-objects-optim-mru later to maint). + + * Codepaths involved in interacting alternate object stores have + been cleaned up. + + * In order for the receiving end of "git push" to inspect the + received history and decide to reject the push, the objects sent + from the sending end need to be made available to the hook and + the mechanism for the connectivity check, and this was done + traditionally by storing the objects in the receiving repository + and letting "git gc" expire them. Instead, store the newly + received objects in a temporary area, and make them available by + reusing the alternate object store mechanism to them only while we + decide if we accept the check, and once we decide, either migrate + them to the repository or purge them immediately. + + * The require_clean_work_tree() helper was recreated in C when "git + pull" was rewritten from shell; the helper is now made available to + other callers in preparation for upcoming "rebase -i" work. + + * "git upload-pack" had its code cleaned-up and performance improved + by reducing use of timestamp-ordered commit-list, which was + replaced with a priority queue. + + * "git diff --no-index" codepath has been updated not to try to peek + into a .git/ directory that happens to be under the current + directory, when we know we are operating outside any repository. + + * Update of the sequencer codebase to make it reusable to reimplement + "rebase -i" continues. + + * Git generally does not explicitly close file descriptors that were + open in the parent process when spawning a child process, but most + of the time the child does not want to access them. As Windows does + not allow removing or renaming a file that has a file descriptor + open, a slow-to-exit child can even break the parent process by + holding onto them. Use O_CLOEXEC flag to open files in various + codepaths. + + * Update "interpret-trailers" machinery and teach it that people in + the real world write all sorts of cruft in the "trailer" that was + originally designed to have the neat-o "Mail-Header: like thing" + and nothing else. + + +Also contains various documentation updates and code clean-ups. + + +Fixes since v2.10 +----------------- + +Unless otherwise noted, all the fixes since v2.9 in the maintenance +track are contained in this release (see the maintenance releases' +notes for details). + + * Clarify various ways to specify the "revision ranges" in the + documentation. + + * "diff-highlight" script (in contrib/) learned to work better with + "git log -p --graph" output. + + * The test framework left the number of tests and success/failure + count in the t/test-results directory, keyed by the name of the + test script plus the process ID. The latter however turned out not + to serve any useful purpose. The process ID part of the filename + has been removed. + + * Having a submodule whose ".git" repository is somehow corrupt + caused a few commands that recurse into submodules to loop forever. + + * "git symbolic-ref -d HEAD" happily removes the symbolic ref, but + the resulting repository becomes an invalid one. Teach the command + to forbid removal of HEAD. + + * A test spawned a short-lived background process, which sometimes + prevented the test directory from getting removed at the end of the + script on some platforms. + + * Update a few tests that used to use GIT_CURL_VERBOSE to use the + newer GIT_TRACE_CURL. + + * "git pack-objects --include-tag" was taught that when we know that + we are sending an object C, we want a tag B that directly points at + C but also a tag A that points at the tag B. We used to miss the + intermediate tag B in some cases. + + * Update Japanese translation for "git-gui". + + * "git fetch http::/site/path" did not die correctly and segfaulted + instead. + + * "git commit-tree" stopped reading commit.gpgsign configuration + variable that was meant for Porcelain "git commit" in Git 2.9; we + forgot to update "git gui" to look at the configuration to match + this change. + + * "git add --chmod={+,-}x" added recently lacked documentation, which has + been corrected. + + * "git log --cherry-pick" used to include merge commits as candidates + to be matched up with other commits, resulting a lot of wasted time. + The patch-id generation logic has been updated to ignore merges and + avoid the wastage. + + * The http transport (with curl-multi option, which is the default + these days) failed to remove curl-easy handle from a curlm session, + which led to unnecessary API failures. + + * There were numerous corner cases in which the configuration files + are read and used or not read at all depending on the directory a + Git command was run, leading to inconsistent behaviour. The code + to set-up repository access at the beginning of a Git process has + been updated to fix them. + (merge 4d0efa1 jk/setup-sequence-update later to maint). + + * "git diff -W" output needs to extend the context backward to + include the header line of the current function and also forward to + include the body of the entire current function up to the header + line of the next one. This process may have to merge two adjacent + hunks, but the code forgot to do so in some cases. + + * Performance tests done via "t/perf" did not use the right + build configuration if the user relied on autoconf generated + configuration. + + * "git format-patch --base=..." feature that was recently added + showed the base commit information after the "-- " e-mail signature + line, which turned out to be inconvenient. The base information + has been moved above the signature line. + + * More i18n. + + * Even when "git pull --rebase=preserve" (and the underlying "git + rebase --preserve") can complete without creating any new commits + (i.e. fast-forwards), it still insisted on having usable ident + information (read: user.email is set correctly), which was less + than nice. As the underlying commands used inside "git rebase" + would fail with a more meaningful error message and advice text + when the bogus ident matters, this extra check was removed. + + * "git gc --aggressive" used to limit the delta-chain length to 250, + which is way too deep for gaining additional space savings and is + detrimental for runtime performance. The limit has been reduced to + 50. + + * Documentation for individual configuration variables to control use + of color (like `color.grep`) said that their default value is + 'false', instead of saying their default is taken from `color.ui`. + When we updated the default value for color.ui from 'false' to + 'auto' quite a while ago, all of them broke. This has been + corrected. + + * The pretty-format specifier "%C(auto)" used by the "log" family of + commands to enable coloring of the output is taught to also issue a + color-reset sequence to the output. + + * A shell script example in check-ref-format documentation has been + fixed. + + * "git checkout <word>" does not follow the usual disambiguation + rules when the <word> can be both a rev and a path, to allow + checking out a branch 'foo' in a project that happens to have a + file 'foo' in the working tree without having to disambiguate. + This was poorly documented and the check was incorrect when the + command was run from a subdirectory. + + * Some codepaths in "git diff" used regexec(3) on a buffer that was + mmap(2)ed, which may not have a terminating NUL, leading to a read + beyond the end of the mapped region. This was fixed by introducing + a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND + extension. + + * The procedure to build Git on Mac OS X for Travis CI hardcoded the + internal directory structure we assumed HomeBrew uses, which was a + no-no. The procedure has been updated to ask HomeBrew things we + need to know to fix this. + + * When "git rebase -i" is given a broken instruction, it told the + user to fix it with "--edit-todo", but didn't say what the step + after that was (i.e. "--continue"). + + * Documentation around tools to import from CVS was fairly outdated. + + * "git clone --recurse-submodules" lost the progress eye-candy in + a recent update, which has been corrected. + + * A low-level function verify_packfile() was meant to show errors + that were detected without dying itself, but under some conditions + it didn't and died instead, which has been fixed. + + * When "git fetch" tries to find where the history of the repository + it runs in has diverged from what the other side has, it has a + mechanism to avoid digging too deep into irrelevant side branches. + This however did not work well over the "smart-http" transport due + to a design bug, which has been fixed. + + * In the codepath that comes up with the hostname to be used in an + e-mail when the user didn't tell us, we looked at the ai_canonname + field in struct addrinfo without making sure it is not NULL first. + + * "git worktree", even though it used the default_abbrev setting that + ought to be affected by the core.abbrev configuration variable, ignored + the variable setting. The command has been taught to read the + default set of configuration variables to correct this. + + * "git init" tried to record core.worktree in the repository's + 'config' file when the GIT_WORK_TREE environment variable was set and + it was different from where GIT_DIR appears as ".git" at its top, + but the logic was faulty when .git is a "gitdir:" file that points + at the real place, causing trouble in working trees that are + managed by "git worktree". This has been corrected. + + * Codepaths that read from an on-disk loose object were too loose in + validating that they are reading a proper object file and + sometimes read past the data they read from the disk, which has + been corrected. H/t to Gustavo Grieco for reporting. + + * The original command line syntax for "git merge", which was "git + merge <msg> HEAD <parent>...", has been deprecated for quite some + time, and "git gui" was the last in-tree user of the syntax. This + is finally fixed, so that we can move forward with the deprecation. + + * An author name that has a backslash-quoted double quote in the + human readable part ("My \"double quoted\" name"), was not unquoted + correctly while applying a patch from a piece of e-mail. + + * Doc update to clarify what "log -3 --reverse" does. + + * Almost everybody uses DEFAULT_ABBREV to refer to the default + setting for the abbreviation, but "git blame" peeked into + underlying variable bypassing the macro for no good reason. + + * The "graph" API used in "git log --graph" miscounted the number of + output columns consumed so far when drawing a padding line, which + has been fixed; this did not affect any existing code as nobody + tried to write anything after the padding on such a line, though. + + * The code that parses the format parameter of the for-each-ref command + has seen a micro-optimization. + + * When we started to use cURL to talk to an imap server, we forgot to explicitly add + imap(s):// before the destination. To some folks, that didn't work + and the library tried to make HTTP(s) requests instead. + + * The ./configure script generated from configure.ac was taught how + to detect support of SSL by libcurl better. + + * The command-line completion script (in contrib/) learned to + complete "git cmd ^mas<HT>" to complete the negative end of + reference to "git cmd ^master". + (merge 49416ad22a cp/completion-negative-refs later to maint). + + * The existing "git fetch --depth=<n>" option was hard to use + correctly when making the history of an existing shallow clone + deeper. A new option, "--deepen=<n>", has been added to make this + easier to use. "git clone" also learned "--shallow-since=<date>" + and "--shallow-exclude=<tag>" options to make it easier to specify + "I am interested only in the recent N months worth of history" and + "Give me only the history since that version". + (merge cccf74e2da nd/shallow-deepen later to maint). + + * "git blame --reverse OLD path" is now DWIMmed to show how lines + in path in an old revision OLD have survived up to the current + commit. + (merge e1d09701a4 jc/blame-reverse later to maint). + + * The http.emptyauth configuration variable is a way to allow an empty username to + pass when attempting to authenticate using mechanisms like + Kerberos. We took an unspecified (NULL) username and sent ":" + (i.e. no username, no password) to CURLOPT_USERPWD, but did not do + the same when the username is explicitly set to an empty string. + + * "git clone" of a local repository can be done at the filesystem + level, but the codepath did not check errors while copying and + adjusting the file that lists alternate object stores. + + * Documentation for "git commit" was updated to clarify that "commit + -p <paths>" adds to the current contents of the index to come up + with what to commit. + + * A stray symbolic link in the $GIT_DIR/refs/ directory could make name + resolution loop forever, which has been corrected. + + * The "submodule.<name>.path" stored in .gitmodules is never copied + to .git/config and such a key in .git/config has no meaning, but + the documentation described it next to submodule.<name>.url + as if both belong to .git/config. This has been fixed. + + * In a worktree created via "git + worktree", "git checkout" attempts to protect users from confusion + by refusing to check out a branch that is already checked out in + another worktree. However, this also prevented checking out a + branch which is designated as the primary branch of a bare + repository, in a worktree that is connected to the bare + repository. The check has been corrected to allow it. + + * "git rebase" immediately after "git clone" failed to find the fork + point from the upstream. + + * When fetching from a remote that has many tags that are irrelevant + to branches we are following, we used to waste way too many cycles + checking if the object pointed at by a tag (that we are not + going to fetch!) exists in our repository too carefully. + + * Protect our code from over-eager compilers. + + * Recent git allows submodule.<name>.branch to use a special token + "." instead of the branch name; the documentation has been updated + to describe it. + + * "git send-email" attempts to pick up valid e-mails from the + trailers, but people in the real world write non-addresses there, like + "Cc: Stable <add@re.ss> # 4.8+", which broke the output depending + on the availability and vintage of the Mail::Address perl module. + (merge dcfafc5214 mm/send-email-cc-cruft-after-address later to maint). + + * The Travis CI configuration we ship ran the tests with the --verbose + option but this risks non-TAP output that happens to be "ok" to be + misinterpreted as TAP signalling a test that passed. This resulted + in unnecessary failures. This has been corrected by introducing a + new mode to run our tests in the test harness to send the verbose + output separately to the log file. + + * Some AsciiDoc formatters mishandle a displayed illustration with + tabs in it. Adjust a few of them in merge-base documentation to + work around them. + + * Fixed a minor regression in "git submodule" that was introduced + when more helper functions were reimplemented in C. + (merge 77b63ac31e sb/submodule-ignore-trailing-slash later to maint). + + * The code that we have used for the past 10+ years to cycle + 4-element ring buffers turns out to be not quite portable in + theoretical world. + (merge bb84735c80 rs/ring-buffer-wraparound later to maint). + + * "git daemon" used fixed-length buffers to turn URLs to the + repository the client asked for into the server side directory + paths, using snprintf() to avoid overflowing these buffers, but + allowed possibly truncated paths to the directory. This has been + tightened to reject such a request that causes an overlong path to be + served. + (merge 6bdb0083be jk/daemon-path-ok-check-truncation later to maint). + + * Recent update to git-sh-setup (a library of shell functions that + are used by our in-tree scripted Porcelain commands) included + another shell library git-sh-i18n without specifying where it is, + relying on the $PATH. This has been fixed to be more explicit by + prefixing with $(git --exec-path) output. + (merge 1073094f30 ak/sh-setup-dot-source-i18n-fix later to maint). + + * Fix for a racy false-positive test failure. + (merge fdf4f6c79b as/merge-attr-sleep later to maint). + + * Portability update and workaround for builds on recent Mac OS X. + (merge a296bc0132 ls/macos-update later to maint). + + * Using a %(HEAD) placeholder in "for-each-ref --format=" option + caused the command to segfault when on an unborn branch. + (merge 84679d470d jc/for-each-ref-head-segfault-fix later to maint). + + * "git rebase -i" did not work well with the core.commentchar + configuration variable for two reasons, both of which have been + fixed. + (merge 882cd23777 js/rebase-i-commentchar-fix later to maint). + + * Other minor doc, test and build updates and code cleanups. + (merge 5c238e29a8 jk/common-main later to maint). + (merge 5a5749e45b ak/pre-receive-hook-template-modefix later to maint). + (merge 6d834ac8f1 jk/rebase-config-insn-fmt-docfix later to maint). + (merge de9f7fa3b0 rs/commit-pptr-simplify later to maint). + (merge 4259d693fc sc/fmt-merge-msg-doc-markup-fix later to maint). + (merge 28fab7b23d nd/test-helpers later to maint). + (merge c2bb0c1d1e rs/cocci later to maint). + (merge 3285b7badb ps/common-info-doc later to maint). + (merge 2b090822e8 nd/worktree-lock later to maint). + (merge 4bd488ea7c jk/create-branch-remove-unused-param later to maint). + (merge 974e0044d6 tk/diffcore-delta-remove-unused later to maint). |