merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

36 files changed, 403 insertions, 63 deletions

diff --git a/third_party/git/Documentation/config/add.txt b/third_party/git/Documentation/config/add.txt
index 4d753f006ec1..c9f748f81cb1 100644
--- a/third_party/git/Documentation/config/add.txt
+++ b/third_party/git/Documentation/config/add.txt
@@ -5,3 +5,8 @@ add.ignore-errors (deprecated)::
 	option of linkgit:git-add[1].  `add.ignore-errors` is deprecated,
 	as it does not follow the usual naming convention for configuration
 	variables.
+
+add.interactive.useBuiltin::
+	[EXPERIMENTAL] Set to `true` to use the experimental built-in
+	implementation of the interactive version of linkgit:git-add[1]
+	instead of the Perl script version. Is `false` by default.
diff --git a/third_party/git/Documentation/config/advice.txt b/third_party/git/Documentation/config/advice.txt
index 6aaa36020298..bdd37c3eaa32 100644
--- a/third_party/git/Documentation/config/advice.txt
+++ b/third_party/git/Documentation/config/advice.txt
@@ -107,4 +107,13 @@ advice.*::
 		editor input from the user.
 	nestedTag::
 		Advice shown if a user attempts to recursively tag a tag object.
+	submoduleAlternateErrorStrategyDie::
+		Advice shown when a submodule.alternateErrorStrategy option
+		configured to "die" causes a fatal error.
+	addIgnoredFile::
+		Advice shown if a user attempts to add an ignored file to
+		the index.
+	addEmptyPathspec::
+		Advice shown if a user runs the add command without providing
+		the pathspec parameter.
 --
diff --git a/third_party/git/Documentation/config/branch.txt b/third_party/git/Documentation/config/branch.txt
index a592d522a744..cc5f3249fc58 100644
--- a/third_party/git/Documentation/config/branch.txt
+++ b/third_party/git/Documentation/config/branch.txt
@@ -81,15 +81,16 @@ branch.<name>.rebase::
 	"git pull" is run. See "pull.rebase" for doing this in a non
 	branch-specific manner.
 +
-When `merges`, pass the `--rebase-merges` option to 'git rebase'
+When `merges` (or just 'm'), pass the `--rebase-merges` option to 'git rebase'
 so that the local merge commits are included in the rebase (see
 linkgit:git-rebase[1] for details).
 +
-When `preserve` (deprecated in favor of `merges`), also pass
+When `preserve` (or just 'p', deprecated in favor of `merges`), also pass
 `--preserve-merges` along to 'git rebase' so that locally committed merge
 commits will not be flattened by running 'git pull'.
 +
-When the value is `interactive`, the rebase is run in interactive mode.
+When the value is `interactive` (or just 'i'), the rebase is run in interactive
+mode.
 +
 *NOTE*: this is a possibly dangerous operation; do *not* use
 it unless you understand the implications (see linkgit:git-rebase[1]
diff --git a/third_party/git/Documentation/config/commitgraph.txt b/third_party/git/Documentation/config/commitgraph.txt
new file mode 100644
index 000000000000..4582c39fc462
--- /dev/null
+++ b/third_party/git/Documentation/config/commitgraph.txt
@@ -0,0 +1,8 @@
+commitGraph.maxNewFilters::
+	Specifies the default value for the `--max-new-filters` option of `git
+	commit-graph write` (c.f., linkgit:git-commit-graph[1]).
+
+commitGraph.readChangedPaths::
+	If true, then git will use the changed-path Bloom filters in the
+	commit-graph file (if it exists, and they are present). Defaults to
+	true. See linkgit:git-commit-graph[1] for more information.
diff --git a/third_party/git/Documentation/config/core.txt b/third_party/git/Documentation/config/core.txt
index 75538d27e7e0..02002cf109e9 100644
--- a/third_party/git/Documentation/config/core.txt
+++ b/third_party/git/Documentation/config/core.txt
@@ -68,6 +68,17 @@ core.fsmonitor::
 	avoiding unnecessary processing of files that have not changed.
 	See the "fsmonitor-watchman" section of linkgit:githooks[5].
 
+core.fsmonitorHookVersion::
+	Sets the version of hook that is to be used when calling fsmonitor.
+	There are currently versions 1 and 2. When this is not set,
+	version 2 will be tried first and if it fails then version 1
+	will be tried. Version 1 uses a timestamp as input to determine
+	which files have changes since that time but some monitors
+	like watchman have race conditions when used with a timestamp.
+	Version 2 uses an opaque string so that the monitor can return
+	something that can be used to determine what files have changed
+	without race conditions.
+
 core.trustctime::
 	If false, the ctime differences between the index and the
 	working tree are ignored; useful when the inode change time
@@ -86,7 +97,9 @@ core.untrackedCache::
 	it will automatically be removed, if set to `false`. Before
 	setting it to `true`, you should check that mtime is working
 	properly on your system.
-	See linkgit:git-update-index[1]. `keep` by default.
+	See linkgit:git-update-index[1]. `keep` by default, unless
+	`feature.manyFiles` is enabled which sets this setting to
+	`true` by default.
 
 core.checkStat::
 	When missing or is set to `default`, many fields in the stat
@@ -386,7 +399,7 @@ the largest projects.  You probably do not need to adjust this value.
 Common unit suffixes of 'k', 'm', or 'g' are supported.
 
 core.deltaBaseCacheLimit::
-	Maximum number of bytes to reserve for caching base objects
+	Maximum number of bytes per thread to reserve for caching base objects
 	that may be referenced by multiple deltified objects.  By storing the
 	entire decompressed base objects in a cache Git is able
 	to avoid unpacking and decompressing frequently used base
@@ -557,6 +570,12 @@ core.unsetenvvars::
 	Defaults to `PERL5LIB` to account for the fact that Git for
 	Windows insists on using its own Perl interpreter.
 
+core.restrictinheritedhandles::
+	Windows-only: override whether spawned processes inherit only standard
+	file handles (`stdin`, `stdout` and `stderr`) or all handles. Can be
+	`auto`, `true` or `false`. Defaults to `auto`, which means `true` on
+	Windows 7 and later, and `false` on older Windows versions.
+
 core.createObject::
 	You can set this to 'link', in which case a hardlink followed by
 	a delete of the source are used to make sure that object creation
@@ -577,7 +596,7 @@ the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
 
 core.commitGraph::
 	If true, then git will read the commit-graph file (if it exists)
-	to parse the graph structure of commits. Defaults to false. See
+	to parse the graph structure of commits. Defaults to true. See
 	linkgit:git-commit-graph[1] for more information.
 
 core.useReplaceRefs::
@@ -591,8 +610,14 @@ core.multiPackIndex::
 	multi-pack-index design document].
 
 core.sparseCheckout::
-	Enable "sparse checkout" feature. See section "Sparse checkout" in
-	linkgit:git-read-tree[1] for more information.
+	Enable "sparse checkout" feature. See linkgit:git-sparse-checkout[1]
+	for more information.
+
+core.sparseCheckoutCone::
+	Enables the "cone mode" of the sparse checkout feature. When the
+	sparse-checkout file contains a limited set of patterns, then this
+	mode provides significant performance advantages. See
+	linkgit:git-sparse-checkout[1] for more information.
 
 core.abbrev::
 	Set the length object names are abbreviated to.  If
diff --git a/third_party/git/Documentation/config/credential.txt b/third_party/git/Documentation/config/credential.txt
index 60fb3189e161..9d01641c282a 100644
--- a/third_party/git/Documentation/config/credential.txt
+++ b/third_party/git/Documentation/config/credential.txt
@@ -1,9 +1,13 @@
 credential.helper::
 	Specify an external helper to be called when a username or
 	password credential is needed; the helper may consult external
-	storage to avoid prompting the user for the credentials. Note
-	that multiple helpers may be defined. See linkgit:gitcredentials[7]
-	for details.
+	storage to avoid prompting the user for the credentials. This is
+	normally the name of a credential helper with possible
+	arguments, but may also be an absolute path with arguments or, if
+	preceded by `!`, shell commands.
++
+Note that multiple helpers may be defined. See linkgit:gitcredentials[7]
+for details and examples.
 
 credential.useHttpPath::
 	When acquiring credentials, consider the "path" component of an http
diff --git a/third_party/git/Documentation/config/diff.txt b/third_party/git/Documentation/config/diff.txt
index 5afb5a2cbc69..c3ae136eba6d 100644
--- a/third_party/git/Documentation/config/diff.txt
+++ b/third_party/git/Documentation/config/diff.txt
@@ -105,6 +105,10 @@ diff.mnemonicPrefix::
 diff.noprefix::
 	If set, 'git diff' does not show any source or destination prefix.
 
+diff.relative::
+	If set to 'true', 'git diff' does not show changes outside of the directory
+	and show pathnames relative to the current directory.
+
 diff.orderFile::
 	File indicating how to order files within a diff.
 	See the '-O' option to linkgit:git-diff[1] for details.
@@ -189,7 +193,7 @@ diff.guitool::
 include::../mergetools-diff.txt[]
 
 diff.indentHeuristic::
-	Set this option to `true` to enable experimental heuristics
+	Set this option to `false` to disable the default heuristics
 	that shift diff hunk boundaries to make patches easier to read.
 
 diff.algorithm::
diff --git a/third_party/git/Documentation/config/extensions.txt b/third_party/git/Documentation/config/extensions.txt
new file mode 100644
index 000000000000..4e23d73cdcad
--- /dev/null
+++ b/third_party/git/Documentation/config/extensions.txt
@@ -0,0 +1,8 @@
+extensions.objectFormat::
+	Specify the hash algorithm to use.  The acceptable values are `sha1` and
+	`sha256`.  If not specified, `sha1` is assumed.  It is an error to specify
+	this key unless `core.repositoryFormatVersion` is 1.
++
+Note that this setting should only be set by linkgit:git-init[1] or
+linkgit:git-clone[1].  Trying to change it after initialization will not
+work and will produce hard-to-diagnose issues.
diff --git a/third_party/git/Documentation/config/feature.txt b/third_party/git/Documentation/config/feature.txt
new file mode 100644
index 000000000000..cdecd04e5bb7
--- /dev/null
+++ b/third_party/git/Documentation/config/feature.txt
@@ -0,0 +1,26 @@
+feature.*::
+	The config settings that start with `feature.` modify the defaults of
+	a group of other config settings. These groups are created by the Git
+	developer community as recommended defaults and are subject to change.
+	In particular, new config options may be added with different defaults.
+
+feature.experimental::
+	Enable config options that are new to Git, and are being considered for
+	future defaults. Config settings included here may be added or removed
+	with each release, including minor version updates. These settings may
+	have unintended interactions since they are so new. Please enable this
+	setting if you are interested in providing feedback on experimental
+	features. The new default values are:
++
+* `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by
+skipping more commits at a time, reducing the number of round trips.
+
+feature.manyFiles::
+	Enable config options that optimize for repos with many files in the
+	working directory. With many files, commands such as `git status` and
+	`git checkout` may be slow and these new defaults improve performance:
++
+* `index.version=4` enables path-prefix compression in the index.
++
+* `core.untrackedCache=true` enables the untracked cache. This setting assumes
+that mtime is working on your machine.
diff --git a/third_party/git/Documentation/config/fetch.txt b/third_party/git/Documentation/config/fetch.txt
index ba890b5884fc..6af6f5edb278 100644
--- a/third_party/git/Documentation/config/fetch.txt
+++ b/third_party/git/Documentation/config/fetch.txt
@@ -1,11 +1,14 @@
 fetch.recurseSubmodules::
-	This option can be either set to a boolean value or to 'on-demand'.
+	This option controls whether `git fetch` (and the underlying fetch
+	in `git pull`) will recursively fetch into populated submodules.
+	This option can be set either to a boolean value or to 'on-demand'.
 	Setting it to a boolean changes the behavior of fetch and pull to
-	unconditionally recurse into submodules when set to true or to not
-	recurse at all when set to false. When set to 'on-demand' (the default
-	value), fetch and pull will only recurse into a populated submodule
-	when its superproject retrieves a commit that updates the submodule's
+	recurse unconditionally into submodules when set to true or to not
+	recurse at all when set to false. When set to 'on-demand', fetch and
+	pull will only recurse into a populated submodule when its
+	superproject retrieves a commit that updates the submodule's
 	reference.
+	Defaults to 'on-demand', or to the value of 'submodule.recurse' if set.
 
 fetch.fsckObjects::
 	If it is set to true, git-fetch-pack will check all fetched
@@ -57,9 +60,13 @@ fetch.negotiationAlgorithm::
 	sent when negotiating the contents of the packfile to be sent by the
 	server. Set to "skipping" to use an algorithm that skips commits in an
 	effort to converge faster, but may result in a larger-than-necessary
-	packfile; The default is "default" which instructs Git to use the default algorithm
+	packfile; or set to "noop" to not send any information at all, which
+	will almost certainly result in a larger-than-necessary packfile, but
+	will skip the negotiation step.
+	The default is "default" which instructs Git to use the default algorithm
 	that never skips commits (unless the server has acknowledged it or one
-	of its descendants).
+	of its descendants). If `feature.experimental` is enabled, then this
+	setting defaults to "skipping".
 	Unknown values will cause 'git fetch' to error out.
 +
 See also the `--negotiation-tip` option for linkgit:git-fetch[1].
@@ -68,3 +75,22 @@ fetch.showForcedUpdates::
 	Set to false to enable `--no-show-forced-updates` in
 	linkgit:git-fetch[1] and linkgit:git-pull[1] commands.
 	Defaults to true.
+
+fetch.parallel::
+	Specifies the maximal number of fetch operations to be run in parallel
+	at a time (submodules, or remotes when the `--multiple` option of
+	linkgit:git-fetch[1] is in effect).
++
+A value of 0 will give some reasonable default. If unset, it defaults to 1.
++
+For submodules, this setting can be overridden using the `submodule.fetchJobs`
+config setting.
+
+fetch.writeCommitGraph::
+	Set to true to write a commit-graph after every `git fetch` command
+	that downloads a pack-file from a remote. Using the `--split` option,
+	most executions will create a very small commit-graph file on top of
+	the existing commit-graph file(s). Occasionally, these files will
+	merge and the write may take longer. Having an updated commit-graph
+	file helps performance of many Git commands, including `git merge-base`,
+	`git push -f`, and `git log --graph`. Defaults to false.
diff --git a/third_party/git/Documentation/config/fmt-merge-msg.txt b/third_party/git/Documentation/config/fmt-merge-msg.txt
index c73cfa90b70c..3fbf40e24f62 100644
--- a/third_party/git/Documentation/config/fmt-merge-msg.txt
+++ b/third_party/git/Documentation/config/fmt-merge-msg.txt
@@ -8,3 +8,15 @@ merge.log::
 	most the specified number of one-line descriptions from the
 	actual commits that are being merged.  Defaults to false, and
 	true is a synonym for 20.
+
+merge.suppressDest::
+	By adding a glob that matches the names of integration
+	branches to this multi-valued configuration variable, the
+	default merge message computed for merges into these
+	integration branches will omit "into <branch name>" from
+	its title.
++
+An element with an empty value can be used to clear the list
+of globs accumulated from previous configuration entries.
+When there is no `merge.suppressDest` variable defined, the
+default value of `master` is used for backward compatibility.
diff --git a/third_party/git/Documentation/config/format.txt b/third_party/git/Documentation/config/format.txt
index 414a5a8a9d7d..c2efd8758a58 100644
--- a/third_party/git/Documentation/config/format.txt
+++ b/third_party/git/Documentation/config/format.txt
@@ -36,6 +36,12 @@ format.subjectPrefix::
 	The default for format-patch is to output files with the '[PATCH]'
 	subject prefix. Use this variable to change that prefix.
 
+format.coverFromDescription::
+	The default mode for format-patch to determine which parts of
+	the cover letter will be populated using the branch's
+	description. See the `--cover-from-description` option in
+	linkgit:git-format-patch[1].
+
 format.signature::
 	The default for format-patch is to output a signature containing
 	the Git version number. Use this variable to change that default.
@@ -51,6 +57,11 @@ format.suffix::
 	`.patch`. Use this variable to change that suffix (make sure to
 	include the dot if you want it).
 
+format.encodeEmailHeaders::
+	Encode email headers that have non-ASCII characters with
+	"Q-encoding" (described in RFC 2047) for email transmission.
+	Defaults to true.
+
 format.pretty::
 	The default pretty format for log/show/whatchanged command,
 	See linkgit:git-log[1], linkgit:git-show[1],
@@ -77,14 +88,17 @@ format.coverLetter::
 	A boolean that controls whether to generate a cover-letter when
 	format-patch is invoked, but in addition can be set to "auto", to
 	generate a cover-letter only when there's more than one patch.
+	Default is false.
 
 format.outputDirectory::
 	Set a custom directory to store the resulting files instead of the
-	current working directory.
+	current working directory. All directory components will be created.
 
 format.useAutoBase::
 	A boolean value which lets you enable the `--base=auto` option of
-	format-patch by default.
+	format-patch by default. Can also be set to "whenAble" to allow
+	enabling `--base=auto` if a suitable base is available, but to skip
+	adding base info otherwise without the format dying.
 
 format.notes::
 	Provides the default value for the `--notes` option to
@@ -99,4 +113,20 @@ If one wishes to use the ref `ref/notes/true`, please use that literal
 instead.
 +
 This configuration can be specified multiple times in order to allow
-multiple notes refs to be included.
+multiple notes refs to be included. In that case, it will behave
+similarly to multiple `--[no-]notes[=]` options passed in. That is, a
+value of `true` will show the default notes, a value of `<ref>` will
+also show notes from that notes ref and a value of `false` will negate
+previous configurations and not show notes.
++
+For example,
++
+------------
+[format]
+	notes = true
+	notes = foo
+	notes = false
+	notes = bar
+------------
++
+will only show notes from `refs/notes/bar`.
diff --git a/third_party/git/Documentation/config/gc.txt b/third_party/git/Documentation/config/gc.txt
index 02b92b18b5c2..00ea0a678ee2 100644
--- a/third_party/git/Documentation/config/gc.txt
+++ b/third_party/git/Documentation/config/gc.txt
@@ -63,7 +63,7 @@ gc.writeCommitGraph::
 	If true, then gc will rewrite the commit-graph file when
 	linkgit:git-gc[1] is run. When using `git gc --auto`
 	the commit-graph will be updated if housekeeping is
-	required. Default is false. See linkgit:git-commit-graph[1]
+	required. Default is true. See linkgit:git-commit-graph[1]
 	for details.
 
 gc.logExpiry::
diff --git a/third_party/git/Documentation/config/gpg.txt b/third_party/git/Documentation/config/gpg.txt
index cce2c8924598..d94025cb3684 100644
--- a/third_party/git/Documentation/config/gpg.txt
+++ b/third_party/git/Documentation/config/gpg.txt
@@ -18,3 +18,18 @@ gpg.<format>.program::
 	chose. (see `gpg.program` and `gpg.format`) `gpg.program` can still
 	be used as a legacy synonym for `gpg.openpgp.program`. The default
 	value for `gpg.x509.program` is "gpgsm".
+
+gpg.minTrustLevel::
+	Specifies a minimum trust level for signature verification.  If
+	this option is unset, then signature verification for merge
+	operations require a key with at least `marginal` trust.  Other
+	operations that perform signature verification require a key
+	with at least `undefined` trust.  Setting this option overrides
+	the required trust-level for all operations.  Supported values,
+	in increasing order of significance:
++
+* `undefined`
+* `never`
+* `marginal`
+* `fully`
+* `ultimate`
diff --git a/third_party/git/Documentation/config/http.txt b/third_party/git/Documentation/config/http.txt
index 5a32f5b0a5a9..3968fbb697ae 100644
--- a/third_party/git/Documentation/config/http.txt
+++ b/third_party/git/Documentation/config/http.txt
@@ -29,6 +29,27 @@ http.proxyAuthMethod::
 * `ntlm` - NTLM authentication (compare the --ntlm option of `curl(1)`)
 --
 
+http.proxySSLCert::
+	The pathname of a file that stores a client certificate to use to authenticate
+	with an HTTPS proxy. Can be overridden by the `GIT_PROXY_SSL_CERT` environment
+	variable.
+
+http.proxySSLKey::
+	The pathname of a file that stores a private key to use to authenticate with
+	an HTTPS proxy. Can be overridden by the `GIT_PROXY_SSL_KEY` environment
+	variable.
+
+http.proxySSLCertPasswordProtected::
+	Enable Git's password prompt for the proxy SSL certificate.  Otherwise OpenSSL
+	will prompt the user, possibly many times, if the certificate or private key
+	is encrypted. Can be overriden by the `GIT_PROXY_SSL_CERT_PASSWORD_PROTECTED`
+	environment variable.
+
+http.proxySSLCAInfo::
+	Pathname to the file containing the certificate bundle that should be used to
+	verify the proxy with when using an HTTPS proxy. Can be overriden by the
+	`GIT_PROXY_SSL_CAINFO` environment variable.
+
 http.emptyAuth::
 	Attempt authentication without seeking a username or password.  This
 	can be used to attempt GSS-Negotiate authentication without specifying
@@ -71,7 +92,7 @@ http.saveCookies::
 http.version::
 	Use the specified HTTP protocol version when communicating with a server.
 	If you want to force the default. The available and default version depend
-	on libcurl. Actually the possible values of
+	on libcurl. Currently the possible values of
 	this option are:
 
 	- HTTP/2
@@ -84,7 +105,7 @@ http.sslVersion::
 	particular configuration of the crypto library in use. Internally
 	this sets the 'CURLOPT_SSL_VERSION' option; see the libcurl
 	documentation for more details on the format of this option and
-	for the ssl version supported. Actually the possible values of
+	for the ssl version supported. Currently the possible values of
 	this option are:
 
 	- sslv2
@@ -199,6 +220,14 @@ http.postBuffer::
 	Transfer-Encoding: chunked is used to avoid creating a
 	massive pack file locally.  Default is 1 MiB, which is
 	sufficient for most requests.
++
+Note that raising this limit is only effective for disabling chunked
+transfer encoding and therefore should be used only where the remote
+server or a proxy only supports HTTP/1.0 or is noncompliant with the
+HTTP standard.  Raising this is not, in general, an effective solution
+for most push problems, but can increase memory consumption
+significantly since the entire buffer is allocated even for small
+pushes.
 
 http.lowSpeedLimit, http.lowSpeedTime::
 	If the HTTP transfer speed is less than 'http.lowSpeedLimit'
diff --git a/third_party/git/Documentation/config/index.txt b/third_party/git/Documentation/config/index.txt
index f18150304106..7cb50b37e98d 100644
--- a/third_party/git/Documentation/config/index.txt
+++ b/third_party/git/Documentation/config/index.txt
@@ -24,3 +24,4 @@ index.threads::
 index.version::
 	Specify the version with which new index files should be
 	initialized.  This does not affect existing repositories.
+	If `feature.manyFiles` is enabled, then the default is 4.
diff --git a/third_party/git/Documentation/config/init.txt b/third_party/git/Documentation/config/init.txt
index 46fa8c6a0827..dc77f8c84468 100644
--- a/third_party/git/Documentation/config/init.txt
+++ b/third_party/git/Documentation/config/init.txt
@@ -1,3 +1,7 @@
 init.templateDir::
 	Specify the directory from which templates will be copied.
 	(See the "TEMPLATE DIRECTORY" section of linkgit:git-init[1].)
+
+init.defaultBranch::
+	Allows overriding the default branch name e.g. when initializing
+	a new repository or when cloning an empty repository.
diff --git a/third_party/git/Documentation/config/log.txt b/third_party/git/Documentation/config/log.txt
index e9e1e397f3fd..208d5fdcaa68 100644
--- a/third_party/git/Documentation/config/log.txt
+++ b/third_party/git/Documentation/config/log.txt
@@ -18,6 +18,12 @@ log.decorate::
 	names are shown. This is the same as the `--decorate` option
 	of the `git log`.
 
+log.excludeDecoration::
+	Exclude the specified patterns from the log decorations. This is
+	similar to the `--decorate-refs-exclude` command-line option, but
+	the config option can be overridden by the `--decorate-refs`
+	option.
+
 log.follow::
 	If `true`, `git log` will act as if the `--follow` option was used when
 	a single <path> is given.  This has the same limitations as `--follow`,
diff --git a/third_party/git/Documentation/config/maintenance.txt b/third_party/git/Documentation/config/maintenance.txt
new file mode 100644
index 000000000000..7cc6700d574d
--- /dev/null
+++ b/third_party/git/Documentation/config/maintenance.txt
@@ -0,0 +1,16 @@
+maintenance.<task>.enabled::
+	This boolean config option controls whether the maintenance task
+	with name `<task>` is run when no `--task` option is specified to
+	`git maintenance run`. These config values are ignored if a
+	`--task` option exists. By default, only `maintenance.gc.enabled`
+	is true.
+
+maintenance.commit-graph.auto::
+	This integer config option controls how often the `commit-graph` task
+	should be run as part of `git maintenance run --auto`. If zero, then
+	the `commit-graph` task will not run with the `--auto` option. A
+	negative value will force the task to run every time. Otherwise, a
+	positive value implies the command should run when the number of
+	reachable commits that are not in the commit-graph file is at least
+	the value of `maintenance.commit-graph.auto`. The default value is
+	100.
diff --git a/third_party/git/Documentation/config/merge.txt b/third_party/git/Documentation/config/merge.txt
index 6a313937f8c0..cb2ed589075b 100644
--- a/third_party/git/Documentation/config/merge.txt
+++ b/third_party/git/Documentation/config/merge.txt
@@ -70,6 +70,16 @@ merge.stat::
 	Whether to print the diffstat between ORIG_HEAD and the merge result
 	at the end of the merge.  True by default.
 
+merge.autoStash::
+	When set to true, automatically create a temporary stash entry
+	before the operation begins, and apply it after the operation
+	ends.  This means that you can run merge on a dirty worktree.
+	However, use with care: the final stash application after a
+	successful merge might result in non-trivial conflicts.
+	This option can be overridden by the `--no-autostash` and
+	`--autostash` options of linkgit:git-merge[1].
+	Defaults to false.
+
 merge.tool::
 	Controls which merge tool is used by linkgit:git-mergetool[1].
 	The list below shows the valid built-in values.
diff --git a/third_party/git/Documentation/config/mergetool.txt b/third_party/git/Documentation/config/mergetool.txt
index 09ed31dbfa9c..16a27443a3ed 100644
--- a/third_party/git/Documentation/config/mergetool.txt
+++ b/third_party/git/Documentation/config/mergetool.txt
@@ -30,6 +30,16 @@ mergetool.meld.hasOutput::
 	to `true` tells Git to unconditionally use the `--output` option,
 	and `false` avoids using `--output`.
 
+mergetool.meld.useAutoMerge::
+	When the `--auto-merge` is given, meld will merge all non-conflicting
+	parts automatically, highlight the conflicting parts and wait for
+	user decision.  Setting `mergetool.meld.useAutoMerge` to `true` tells
+	Git to unconditionally use the `--auto-merge` option with `meld`.
+	Setting this value to `auto` makes git detect whether `--auto-merge`
+	is supported and will only use `--auto-merge` when available.  A
+	value of `false` avoids using `--auto-merge` altogether, and is the
+	default value.
+
 mergetool.keepBackup::
 	After performing a merge, the original file with conflict markers
 	can be saved as a file with a `.orig` extension.  If this variable
diff --git a/third_party/git/Documentation/config/pack.txt b/third_party/git/Documentation/config/pack.txt
index 9cdcfa732478..837f1b16792f 100644
--- a/third_party/git/Documentation/config/pack.txt
+++ b/third_party/git/Documentation/config/pack.txt
@@ -27,6 +27,13 @@ Note that changing the compression level will not automatically recompress
 all existing objects. You can force recompression by passing the -F option
 to linkgit:git-repack[1].
 
+pack.allowPackReuse::
+	When true, and when reachability bitmaps are enabled,
+	pack-objects will try to send parts of the bitmapped packfile
+	verbatim. This can reduce memory and CPU usage to serve fetches,
+	but might result in sending a slightly larger pack. Defaults to
+	true.
+
 pack.island::
 	An extended regular expression configuring a set of delta
 	islands. See "DELTA ISLANDS" in linkgit:git-pack-objects[1]
@@ -112,7 +119,8 @@ pack.useSparse::
 	objects. This can have significant performance benefits when
 	computing a pack to send a small change. However, it is possible
 	that extra objects are added to the pack-file if the included
-	commits contain certain types of direct renames.
+	commits contain certain types of direct renames. Default is
+	`true`.
 
 pack.writeBitmaps (deprecated)::
 	This is a deprecated synonym for `repack.writeBitmaps`.
diff --git a/third_party/git/Documentation/config/protocol.txt b/third_party/git/Documentation/config/protocol.txt
index bfccc074913e..756591d77b08 100644
--- a/third_party/git/Documentation/config/protocol.txt
+++ b/third_party/git/Documentation/config/protocol.txt
@@ -45,11 +45,10 @@ The protocol names currently used by git are:
 --
 
 protocol.version::
-	Experimental. If set, clients will attempt to communicate with a
-	server using the specified protocol version.  If unset, no
-	attempt will be made by the client to communicate using a
-	particular protocol version, this results in protocol version 0
-	being used.
+	If set, clients will attempt to communicate with a server
+	using the specified protocol version.  If the server does
+	not support it, communication falls back to version 0.
+	If unset, the default is `2`.
 	Supported versions:
 +
 --
diff --git a/third_party/git/Documentation/config/pull.txt b/third_party/git/Documentation/config/pull.txt
index b87cab31b39c..540483060956 100644
--- a/third_party/git/Documentation/config/pull.txt
+++ b/third_party/git/Documentation/config/pull.txt
@@ -14,15 +14,16 @@ pull.rebase::
 	pull" is run. See "branch.<name>.rebase" for setting this on a
 	per-branch basis.
 +
-When `merges`, pass the `--rebase-merges` option to 'git rebase'
+When `merges` (or just 'm'), pass the `--rebase-merges` option to 'git rebase'
 so that the local merge commits are included in the rebase (see
 linkgit:git-rebase[1] for details).
 +
-When `preserve` (deprecated in favor of `merges`), also pass
+When `preserve` (or just 'p', deprecated in favor of `merges`), also pass
 `--preserve-merges` along to 'git rebase' so that locally committed merge
 commits will not be flattened by running 'git pull'.
 +
-When the value is `interactive`, the rebase is run in interactive mode.
+When the value is `interactive` (or just 'i'), the rebase is run in interactive
+mode.
 +
 *NOTE*: this is a possibly dangerous operation; do *not* use
 it unless you understand the implications (see linkgit:git-rebase[1]
diff --git a/third_party/git/Documentation/config/push.txt b/third_party/git/Documentation/config/push.txt
index 0a0e000569d8..f5e5b38c6889 100644
--- a/third_party/git/Documentation/config/push.txt
+++ b/third_party/git/Documentation/config/push.txt
@@ -1,6 +1,7 @@
 push.default::
 	Defines the action `git push` should take if no refspec is
-	explicitly given.  Different values are well-suited for
+	given (whether from the command-line, config, or elsewhere).
+	Different values are well-suited for
 	specific workflows; for instance, in a purely central workflow
 	(i.e. the fetch source is equal to the push destination),
 	`upstream` is probably what you want.  Possible values are:
@@ -8,7 +9,7 @@ push.default::
 --
 
 * `nothing` - do not push anything (error out) unless a refspec is
-  explicitly given. This is primarily meant for people who want to
+  given. This is primarily meant for people who want to
   avoid mistakes by always being explicit.
 
 * `current` - push the current branch to update a branch with the same
@@ -79,7 +80,7 @@ higher priority configuration file (e.g. `.git/config` in a
 repository) to clear the values inherited from a lower priority
 configuration files (e.g. `$HOME/.gitconfig`).
 +
---
+----
 
 Example:
 
@@ -96,7 +97,7 @@ repo/.git/config
 
 This will result in only b (a and c are cleared).
 
---
+----
 
 push.recurseSubmodules::
 	Make sure all submodule commits used by the revisions to be pushed
@@ -111,3 +112,5 @@ push.recurseSubmodules::
 	is 'no' then default behavior of ignoring submodules when pushing
 	is retained. You may override this configuration at time of push by
 	specifying '--recurse-submodules=check|on-demand|no'.
+	If not set, 'no' is used by default, unless 'submodule.recurse' is
+	set (in which case a 'true' value means 'on-demand').
diff --git a/third_party/git/Documentation/config/rebase.txt b/third_party/git/Documentation/config/rebase.txt
index d98e32d812e7..7f7a07d22f86 100644
--- a/third_party/git/Documentation/config/rebase.txt
+++ b/third_party/git/Documentation/config/rebase.txt
@@ -5,6 +5,12 @@ rebase.useBuiltin::
 	is always used. Setting this will emit a warning, to alert any
 	remaining users that setting this now does nothing.
 
+rebase.backend::
+	Default backend to use for rebasing.  Possible choices are
+	'apply' or 'merge'.  In the future, if the merge backend gains
+	all remaining capabilities of the apply backend, this setting
+	may become unused.
+
 rebase.stat::
 	Whether to show a diffstat of what changed upstream since the last
 	rebase. False by default.
diff --git a/third_party/git/Documentation/config/receive.txt b/third_party/git/Documentation/config/receive.txt
index 65f78aac37fd..85d5b5a3d2d8 100644
--- a/third_party/git/Documentation/config/receive.txt
+++ b/third_party/git/Documentation/config/receive.txt
@@ -114,6 +114,28 @@ receive.hideRefs::
 	An attempt to update or delete a hidden ref by `git push` is
 	rejected.
 
+receive.procReceiveRefs::
+	This is a multi-valued variable that defines reference prefixes
+	to match the commands in `receive-pack`.  Commands matching the
+	prefixes will be executed by an external hook "proc-receive",
+	instead of the internal `execute_commands` function.  If this
+	variable is not defined, the "proc-receive" hook will never be
+	used, and all commands will be executed by the internal
+	`execute_commands` function.
++
+For example, if this variable is set to "refs/for", pushing to reference
+such as "refs/for/master" will not create or update a reference named
+"refs/for/master", but may create or update a pull request directly by
+running the hook "proc-receive".
++
+Optional modifiers can be provided in the beginning of the value to filter
+commands for specific actions: create (a), modify (m), delete (d).
+A `!` can be included in the modifiers to negate the reference prefix entry.
+E.g.:
++
+	git config --system --add receive.procReceiveRefs ad:refs/heads
+	git config --system --add receive.procReceiveRefs !:refs/heads
+
 receive.updateServerInfo::
 	If set to true, git-receive-pack will run git-update-server-info
 	after receiving data from git-push and updating refs.
diff --git a/third_party/git/Documentation/config/remote.txt b/third_party/git/Documentation/config/remote.txt
index 6c4cad83a2c9..a8e6437a9035 100644
--- a/third_party/git/Documentation/config/remote.txt
+++ b/third_party/git/Documentation/config/remote.txt
@@ -76,3 +76,11 @@ remote.<name>.pruneTags::
 +
 See also `remote.<name>.prune` and the PRUNING section of
 linkgit:git-fetch[1].
+
+remote.<name>.promisor::
+	When set to true, this remote will be used to fetch promisor
+	objects.
+
+remote.<name>.partialclonefilter::
+	The filter that will be applied when fetching from this
+	promisor remote.
diff --git a/third_party/git/Documentation/config/sendemail.txt b/third_party/git/Documentation/config/sendemail.txt
index 0006faf800ae..cbc5af42fdf0 100644
--- a/third_party/git/Documentation/config/sendemail.txt
+++ b/third_party/git/Documentation/config/sendemail.txt
@@ -61,3 +61,8 @@ sendemail.smtpBatchSize::
 sendemail.smtpReloginDelay::
 	Seconds wait before reconnecting to smtp server.
 	See also the `--relogin-delay` option of linkgit:git-send-email[1].
+
+sendemail.forbidSendmailVariables::
+	To avoid common misconfiguration mistakes, linkgit:git-send-email[1]
+	will abort with a warning if any configuration options for "sendmail"
+	exist. Set this variable to bypass the check.
diff --git a/third_party/git/Documentation/config/stash.txt b/third_party/git/Documentation/config/stash.txt
index abc7ef4a3a5c..00eb35434e88 100644
--- a/third_party/git/Documentation/config/stash.txt
+++ b/third_party/git/Documentation/config/stash.txt
@@ -1,17 +1,9 @@
 stash.useBuiltin::
-       Set to `false` to use the legacy shell script implementation of
-       linkgit:git-stash[1]. Is `true` by default, which means use
-       the built-in rewrite of it in C.
-+
-The C rewrite is first included with Git version 2.22 (and Git for Windows
-version 2.19). This option serves as an escape hatch to re-enable the
-legacy version in case any bugs are found in the rewrite. This option and
-the shell script version of linkgit:git-stash[1] will be removed in some
-future release.
-+
-If you find some reason to set this option to `false`, other than
-one-off testing, you should report the behavior difference as a bug in
-Git (see https://git-scm.com/community for details).
+	Unused configuration variable.  Used in Git versions 2.22 to
+	2.26 as an escape hatch to enable the legacy shellscript
+	implementation of stash.  Now the built-in rewrite of it in C
+	is always used. Setting this will emit a warning, to alert any
+	remaining users that setting this now does nothing.
 
 stash.showPatch::
 	If this is set to true, the `git stash show` command without an
diff --git a/third_party/git/Documentation/config/submodule.txt b/third_party/git/Documentation/config/submodule.txt
index 0a1293b05135..d7a63c8c12bb 100644
--- a/third_party/git/Documentation/config/submodule.txt
+++ b/third_party/git/Documentation/config/submodule.txt
@@ -59,9 +59,17 @@ submodule.active::
 
 submodule.recurse::
 	Specifies if commands recurse into submodules by default. This
-	applies to all commands that have a `--recurse-submodules` option,
-	except `clone`.
+	applies to all commands that have a `--recurse-submodules` option
+	(`checkout`, `fetch`, `grep`, `pull`, `push`, `read-tree`, `reset`,
+	`restore` and `switch`) except `clone` and `ls-files`.
 	Defaults to false.
+	When set to true, it can be deactivated via the
+	`--no-recurse-submodules` option. Note that some Git commands
+	lacking this option may call some of the above commands affected by
+	`submodule.recurse`; for instance `git remote update` will call
+	`git fetch` but does not have a `--no-recurse-submodules` option.
+	For these commands a workaround is to temporarily change the
+	configuration value by using `git -c submodule.recurse=0`.
 
 submodule.fetchJobs::
 	Specifies how many submodules are fetched/cloned at the same time.
@@ -79,4 +87,6 @@ submodule.alternateLocation::
 submodule.alternateErrorStrategy::
 	Specifies how to treat errors with the alternates for a submodule
 	as computed via `submodule.alternateLocation`. Possible values are
-	`ignore`, `info`, `die`. Default is `die`.
+	`ignore`, `info`, `die`. Default is `die`. Note that if set to `ignore`
+	or `info`, and if there is an error with the computed alternate, the
+	clone proceeds as if no alternate was specified.
diff --git a/third_party/git/Documentation/config/tag.txt b/third_party/git/Documentation/config/tag.txt
index ef5adb3f420d..5062a057ffc6 100644
--- a/third_party/git/Documentation/config/tag.txt
+++ b/third_party/git/Documentation/config/tag.txt
@@ -13,12 +13,5 @@ tag.gpgSign::
 	Use of this option when running in an automated script can
 	result in a large number of tags being signed. It is therefore
 	convenient to use an agent to avoid typing your gpg passphrase
-	several times. Note that this option doesn't affects tag signing
+	several times. Note that this option doesn't affect tag signing
 	behavior enabled by "-u <keyid>" or "--local-user=<keyid>" options.
-
-tar.umask::
-	This variable can be used to restrict the permission bits of
-	tar archive entries.  The default is 0002, which turns off the
-	world write bit.  The special value "user" indicates that the
-	archiving user's umask will be used instead.  See umask(2) and
-	linkgit:git-archive[1].
diff --git a/third_party/git/Documentation/config/tar.txt b/third_party/git/Documentation/config/tar.txt
new file mode 100644
index 000000000000..de8ff48ea9d4
--- /dev/null
+++ b/third_party/git/Documentation/config/tar.txt
@@ -0,0 +1,6 @@
+tar.umask::
+	This variable can be used to restrict the permission bits of
+	tar archive entries.  The default is 0002, which turns off the
+	world write bit.  The special value "user" indicates that the
+	archiving user's umask will be used instead.  See umask(2) and
+	linkgit:git-archive[1].
diff --git a/third_party/git/Documentation/config/trace2.txt b/third_party/git/Documentation/config/trace2.txt
index 2edbfb02fe5b..01d3afd8a8b3 100644
--- a/third_party/git/Documentation/config/trace2.txt
+++ b/third_party/git/Documentation/config/trace2.txt
@@ -48,9 +48,24 @@ trace2.configParams::
 	May be overridden by the `GIT_TRACE2_CONFIG_PARAMS` environment
 	variable.  Unset by default.
 
+trace2.envVars::
+	A comma-separated list of "important" environment variables that should
+	be recorded in the trace2 output.  For example,
+	`GIT_HTTP_USER_AGENT,GIT_CONFIG` would cause the trace2 output to
+	contain events listing the overrides for HTTP user agent and the
+	location of the Git configuration file (assuming any are set).  May be
+	overriden by the `GIT_TRACE2_ENV_VARS` environment variable.  Unset by
+	default.
+
 trace2.destinationDebug::
 	Boolean.  When true Git will print error messages when a
 	trace target destination cannot be opened for writing.
 	By default, these errors are suppressed and tracing is
 	silently disabled.  May be overridden by the
 	`GIT_TRACE2_DST_DEBUG` environment variable.
+
+trace2.maxFiles::
+	Integer.  When writing trace files to a target directory, do not
+	write additional traces if we would exceed this many files. Instead,
+	write a sentinel file that will block further tracing to this
+	directory. Defaults to 0, which disables this check.
diff --git a/third_party/git/Documentation/config/uploadpack.txt b/third_party/git/Documentation/config/uploadpack.txt
index ed1c835695c3..b0d761282cd6 100644
--- a/third_party/git/Documentation/config/uploadpack.txt
+++ b/third_party/git/Documentation/config/uploadpack.txt
@@ -57,6 +57,24 @@ uploadpack.allowFilter::
 	If this option is set, `upload-pack` will support partial
 	clone and partial fetch object filtering.
 
+uploadpackfilter.allow::
+	Provides a default value for unspecified object filters (see: the
+	below configuration variable).
+	Defaults to `true`.
+
+uploadpackfilter.<filter>.allow::
+	Explicitly allow or ban the object filter corresponding to
+	`<filter>`, where `<filter>` may be one of: `blob:none`,
+	`blob:limit`, `tree`, `sparse:oid`, or `combine`. If using
+	combined filters, both `combine` and all of the nested filter
+	kinds must be allowed. Defaults to `uploadpackfilter.allow`.
+
+uploadpackfilter.tree.maxDepth::
+	Only allow `--filter=tree:<n>` when `<n>` is no more than the value of
+	`uploadpackfilter.tree.maxDepth`. If set, this also implies
+	`uploadpackfilter.tree.allow=true`, unless this configuration
+	variable had already been set. Has no effect if unset.
+
 uploadpack.allowRefInWant::
 	If this option is set, `upload-pack` will support the `ref-in-want`
 	feature of the protocol version 2 `fetch` command.  This feature
diff --git a/third_party/git/Documentation/config/user.txt b/third_party/git/Documentation/config/user.txt
index 0557cbbceb81..59aec7c3aed3 100644
--- a/third_party/git/Documentation/config/user.txt
+++ b/third_party/git/Documentation/config/user.txt
@@ -13,7 +13,12 @@ committer.email::
 	Also, all of these can be overridden by the `GIT_AUTHOR_NAME`,
 	`GIT_AUTHOR_EMAIL`, `GIT_COMMITTER_NAME`,
 	`GIT_COMMITTER_EMAIL` and `EMAIL` environment variables.
-	See linkgit:git-commit-tree[1] for more information.
++
+Note that the `name` forms of these variables conventionally refer to
+some form of a personal name.  See linkgit:git-commit[1] and the
+environment variables section of linkgit:git[1] for more information on
+these settings and the `credential.username` option if you're looking
+for authentication credentials instead.
 
 user.useConfigOnly::
 	Instruct Git to avoid trying to guess defaults for `user.email`