21 files changed, 268 insertions, 66 deletions
diff --git a/Documentation/RelNotes/2.22.0.txt b/Documentation/RelNotes/2.22.0.txt
index 114f147fd6..91e6ae9887 100644
--- a/Documentation/RelNotes/2.22.0.txt
+++ b/Documentation/RelNotes/2.22.0.txt
@@ -4,6 +4,13 @@ Git 2.22 Release Notes
 Updates since v2.21
 -------------------
 
+Backward compatibility note
+
+ * The filter specification "--filter=sparse:path=<path>" used to
+   create a lazy/partial clone has been removed.  Using a blob that is
+   part of the project as sparse specification is still supported with
+   the "--filter=sparse:oid=<blob>" option.
+
 UI, Workflows & Features
 
  * "git checkout --no-overlay" can be used to trigger a new mode of
@@ -99,6 +106,18 @@ UI, Workflows & Features
    repositories now; also the pathname hash-cache is created by
    default to avoid making crappy deltas when repacking.
 
+ * "git branch new A...B" and "git checkout -b new A...B" have been
+   taught that in their contexts, the notation A...B means "the merge
+   base between these two commits", just like "git checkout A...B"
+   detaches HEAD at that commit.
+
+ * Update "git difftool" and "git mergetool" so that the combinations
+   of {diff,merge}.{tool,guitool} configuration variables serve as
+   fallback settings of each other in a sensible order.
+
+ * The "--dir-diff" mode of "git difftool" is not useful in "--no-index"
+   mode; they are now explicitly marked as mutually incompatible.
+
 
 Performance, Internal Implementation, Development Support etc.
 
@@ -169,7 +188,7 @@ Performance, Internal Implementation, Development Support etc.
    been optimized out.
 
  * Mechanically and systematically drop "extern" from function
-   declarlation.
+   declaration.
 
  * The script to aggregate perf result unconditionally depended on
    libjson-perl even though it did not have to, which has been
@@ -178,6 +197,27 @@ Performance, Internal Implementation, Development Support etc.
  * The internal implementation of "git rebase -i" has been updated to
    avoid forking a separate "rebase--interactive" process.
 
+ * Allow DEP and ASLR for Windows build to for security hardening.
+
+ * Performance test framework has been broken and measured the version
+   of Git that happens to be on $PATH, not the specified one to
+   measure, for a while, which has been corrected.
+
+ * Optionally "make coccicheck" can feed multiple source files to
+   spatch, gaining performance while spending more memory.
+
+ * Attempt to use an abbreviated option in "git clone --recurs" is
+   responded by a request to disambiguate between --recursive and
+   --recurse-submodules, which is bad because these two are synonyms.
+   The parse-options API has been extended to define such synonyms
+   more easily and not produce an unnecessary failure.
+
+ * A pair of private functions in http.c that had names similar to
+   fread/fwrite did not return the number of elements, which was found
+   to be confusing.
+
+ * Update collision-detecting SHA-1 code to build properly on HP-UX.
+
 
 Fixes since v2.21
 -----------------
@@ -237,7 +277,7 @@ Fixes since v2.21
  * On platforms where "git fetch" is killed with SIGPIPE (e.g. OSX),
    the upload-pack that runs on the other end that hangs up after
    detecting an error could cause "git fetch" to die with a signal,
-   which led to a flakey test.  "git fetch" now ignores SIGPIPE during
+   which led to a flaky test.  "git fetch" now ignores SIGPIPE during
    the network portion of its operation (this is not a problem as we
    check the return status from our write(2)s).
    (merge 143588949c jk/no-sigpipe-during-network-transport later to maint).
@@ -325,7 +365,7 @@ Fixes since v2.21
    (merge b5a0bd694c nd/read-tree-reset-doc later to maint).
 
  * Code clean-up around a much-less-important-than-it-used-to-be
-   update_server_info() funtion.
+   update_server_info() function.
    (merge b3223761c8 jk/server-info-rabbit-hole later to maint).
 
  * The message given when "git commit -a <paths>" errors out has been
@@ -417,7 +457,7 @@ Fixes since v2.21
  * When given a tag that points at a commit-ish, "git replace --graft"
    failed to peel the tag before writing a replace ref, which did not
    make sense because the old graft mechanism the feature wants to
-   mimick only allowed to replace one commit object with another.
+   mimic only allowed to replace one commit object with another.
    This has been fixed.
    (merge ee521ec4cb cc/replace-graft-peel-tags later to maint).
 
@@ -467,13 +507,48 @@ Fixes since v2.21
    conflicts are resolved in working tree *.h files but before the
    resolved results are added to the index.  This has been corrected.
 
- * "git chery-pick" (and "revert" that shares the same runtime engine)
+ * "git cherry-pick" (and "revert" that shares the same runtime engine)
    that deals with multiple commits got confused when the final step
    gets stopped with a conflict and the user concluded the sequence
    with "git commit".  Attempt to fix it by cleaning up the state
    files used by these commands in such a situation.
    (merge 4a72486de9 pw/clean-sequencer-state-upon-final-commit later to maint).
 
+ * On a filesystem like HFS+, the names of the refs stored as filesystem
+   entities may become different from what the end-user expects, just
+   like files in the working tree get "renamed".  Work around the
+   mismatch by paying attention to the core.precomposeUnicode
+   configuration.
+   (merge 8e712ef6fc en/unicode-in-refnames later to maint).
+
+ * The code to generate the multi-pack idx file was not prepared to
+   see too many packfiles and ran out of open file descriptor, which
+   has been corrected.
+
+ * To run tests for Git SVN, our scripts for CI used to install the
+   git-svn package (in the hope that it would bring in the right
+   dependencies).  This has been updated to install the more direct
+   dependency, namely, libsvn-perl.
+   (merge db864306cf sg/ci-libsvn-perl later to maint).
+
+ * "git cvsexportcommit" running on msys did not expect cvsnt showed
+   "cvs status" output with CRLF line endings.
+
+ * The fsmonitor interface got out of sync after the in-core index
+   file gets discarded, which has been corrected.
+   (merge 398a3b0899 js/fsmonitor-refresh-after-discarding-index later to maint).
+
+ * "git status" did not know that the "label" instruction in the
+   todo-list "rebase -i -r" uses should not be shown as a hex object
+   name.
+
+ * A prerequisite check in the test suite to see if a working jgit is
+   available was made more robust.
+   (merge abd0f28983 tz/test-lib-check-working-jgit later to maint).
+
+ * The codepath to parse :<path> that obtains the object name for an
+   indexed object has been made more robust.
+
  * Code cleanup, docfix, build fix, etc.
    (merge 11f470aee7 jc/test-yes-doc later to maint).
    (merge 90503a240b js/doc-symref-in-proto-v1 later to maint).
@@ -510,3 +585,13 @@ Fixes since v2.21
    (merge d8083e4180 km/t3000-retitle later to maint).
    (merge 9e4cbccbd7 tz/git-svn-doc-markup-fix later to maint).
    (merge da9ca955a7 jk/ls-files-doc-markup-fix later to maint).
+   (merge 6804ba3a58 cw/diff-highlight later to maint).
+   (merge 1a8787144d nd/submodule-helper-incomplete-line-fix later to maint).
+   (merge d9ef573837 jk/apache-lsan later to maint).
+   (merge c871fbee2b js/t6500-use-windows-pid-on-mingw later to maint).
+   (merge ce4c7bfc90 bl/t4253-exit-code-from-format-patch later to maint).
+   (merge 397a46db78 js/t5580-unc-alternate-test later to maint).
+   (merge d4907720a2 cm/notes-comment-fix later to maint).
+   (merge 9dde06de13 cb/http-push-null-in-message-fix later to maint).
+   (merge 4c785c0edc js/rebase-config-bitfix later to maint).
+   (merge 8e9fe16c87 es/doc-gitsubmodules-markup later to maint).
diff --git a/Documentation/config/format.txt b/Documentation/config/format.txt
index dc77941c48..414a5a8a9d 100644
--- a/Documentation/config/format.txt
+++ b/Documentation/config/format.txt
@@ -85,3 +85,18 @@ format.outputDirectory::
 format.useAutoBase::
 	A boolean value which lets you enable the `--base=auto` option of
 	format-patch by default.
+
+format.notes::
+	Provides the default value for the `--notes` option to
+	format-patch. Accepts a boolean value, or a ref which specifies
+	where to get notes. If false, format-patch defaults to
+	`--no-notes`. If true, format-patch defaults to `--notes`. If
+	set to a non-boolean value, format-patch defaults to
+	`--notes=<ref>`, where `ref` is the non-boolean value. Defaults
+	to false.
++
+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.
diff --git a/Documentation/config/stash.txt b/Documentation/config/stash.txt
index c583d46d6b..7710758efb 100644
--- a/Documentation/config/stash.txt
+++ b/Documentation/config/stash.txt
@@ -1,3 +1,18 @@
+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 an 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).
+
 stash.showPatch::
 	If this is set to true, the `git stash show` command without an
 	option will show the stash entry in patch form.  Defaults to false.
diff --git a/Documentation/config/trace2.txt b/Documentation/config/trace2.txt
index a5f409c1c1..2edbfb02fe 100644
--- a/Documentation/config/trace2.txt
+++ b/Documentation/config/trace2.txt
@@ -4,17 +4,17 @@ command line arguments are not respected.
 
 trace2.normalTarget::
 	This variable controls the normal target destination.
-	It may be overridden by the `GIT_TR2` environment variable.
+	It may be overridden by the `GIT_TRACE2` environment variable.
 	The following table shows possible values.
 
 trace2.perfTarget::
 	This variable controls the performance target destination.
-	It may be overridden by the `GIT_TR2_PERF` environment variable.
+	It may be overridden by the `GIT_TRACE2_PERF` environment variable.
 	The following table shows possible values.
 
 trace2.eventTarget::
 	This variable controls the event target destination.
-	It may be overridden by the `GIT_TR2_EVENT` environment variable.
+	It may be overridden by the `GIT_TRACE2_EVENT` environment variable.
 	The following table shows possible values.
 +
 include::../trace2-target-values.txt[]
@@ -22,22 +22,22 @@ include::../trace2-target-values.txt[]
 trace2.normalBrief::
 	Boolean.  When true `time`, `filename`, and `line` fields are
 	omitted from normal output.  May be overridden by the
-	`GIT_TR2_BRIEF` environment variable.  Defaults to false.
+	`GIT_TRACE2_BRIEF` environment variable.  Defaults to false.
 
 trace2.perfBrief::
 	Boolean.  When true `time`, `filename`, and `line` fields are
 	omitted from PERF output.  May be overridden by the
-	`GIT_TR2_PERF_BRIEF` environment variable.  Defaults to false.
+	`GIT_TRACE2_PERF_BRIEF` environment variable.  Defaults to false.
 
 trace2.eventBrief::
 	Boolean.  When true `time`, `filename`, and `line` fields are
 	omitted from event output.  May be overridden by the
-	`GIT_TR2_EVENT_BRIEF` environment variable.  Defaults to false.
+	`GIT_TRACE2_EVENT_BRIEF` environment variable.  Defaults to false.
 
 trace2.eventNesting::
 	Integer.  Specifies desired depth of nested regions in the
 	event output.  Regions deeper than this value will be
-	omitted.  May be overridden by the `GIT_TR2_EVENT_NESTING`
+	omitted.  May be overridden by the `GIT_TRACE2_EVENT_NESTING`
 	environment variable.  Defaults to 2.
 
 trace2.configParams::
@@ -45,7 +45,7 @@ trace2.configParams::
 	settings that should be recorded in the trace2 output.
 	For example, `core.*,remote.*.url` would cause the trace2
 	output to contain events listing each configured remote.
-	May be overridden by the `GIT_TR2_CONFIG_PARAMS` environment
+	May be overridden by the `GIT_TRACE2_CONFIG_PARAMS` environment
 	variable.  Unset by default.
 
 trace2.destinationDebug::
@@ -53,4 +53,4 @@ trace2.destinationDebug::
 	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_TR2_DST_DEBUG` environment variable.
+	`GIT_TRACE2_DST_DEBUG` environment variable.
diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index 0cd87ddeff..6ebd512b4f 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -45,7 +45,11 @@ argument is missing it defaults to `HEAD` (i.e. the tip of the current
 branch).
 
 The command's second form creates a new branch head named <branchname>
-which points to the current `HEAD`, or <start-point> if given.
+which points to the current `HEAD`, or <start-point> if given. As a
+special case, for <start-point>, you may use `"A...B"` as a shortcut for
+the merge base of `A` and `B` if there is exactly one merge base. You
+can leave out at most one of `A` and `B`, in which case it defaults to
+`HEAD`.
 
 Note that this will create the new branch, but it will not switch the
 working tree to it; use "git checkout <newbranch>" to switch to the
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 877e5f503a..964f912d29 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -313,6 +313,10 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 <start_point>::
 	The name of a commit at which to start the new branch; see
 	linkgit:git-branch[1] for details. Defaults to HEAD.
++
+As a special case, you may use `"A...B"` as a shortcut for the
+merge base of `A` and `B` if there is exactly one merge base. You can
+leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
 <tree-ish>::
 	Tree to checkout from (when paths are given). If not specified,
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 96c26e6aa8..484c485fd0 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -90,7 +90,9 @@ instead.  `--no-symlinks` is the default on Windows.
 	When 'git-difftool' is invoked with the `-g` or `--gui` option
 	the default diff tool will be read from the configured
 	`diff.guitool` variable instead of `diff.tool`. The `--no-gui`
-	option can be used to override this setting.
+	option can be used to override this setting. If `diff.guitool`
+	is not set, we will fallback in the order of `merge.guitool`,
+	`diff.tool`, `merge.tool` until a tool is found.
 
 --[no-]trust-exit-code::
 	'git-difftool' invokes a diff tool individually on each file.
diff --git a/Documentation/git-fast-export.txt b/Documentation/git-fast-export.txt
index 64c01ba918..11427acdde 100644
--- a/Documentation/git-fast-export.txt
+++ b/Documentation/git-fast-export.txt
@@ -129,6 +129,13 @@ marks the same across runs.
 	for intermediary filters (e.g. for rewriting commit messages
 	which refer to older commits, or for stripping blobs by id).
 
+--reencode=(yes|no|abort)::
+	Specify how to handle `encoding` header in commit objects.  When
+	asking to 'abort' (which is the default), this program will die
+	when encountering such a commit object.  With 'yes', the commit
+	message will be reencoded into UTF-8.  With 'no', the original
+	encoding will be preserved.
+
 --refspec::
 	Apply the specified refspec to each ref exported. Multiple of them can
 	be specified.
diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index d65cdb3d08..7baf9e47b5 100644
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -388,6 +388,7 @@ change to the project.
 	original-oid?
 	('author' (SP <name>)? SP LT <email> GT SP <when> LF)?
 	'committer' (SP <name>)? SP LT <email> GT SP <when> LF
+	('encoding' SP <encoding>)?
 	data
 	('from' SP <commit-ish> LF)?
 	('merge' SP <commit-ish> LF)?
@@ -455,6 +456,12 @@ that was selected by the --date-format=<fmt> command-line option.
 See ``Date Formats'' above for the set of supported formats, and
 their syntax.
 
+`encoding`
+^^^^^^^^^^
+The optional `encoding` command indicates the encoding of the commit
+message.  Most commits are UTF-8 and the encoding is omitted, but this
+allows importing commit messages into git without first reencoding them.
+
 `from`
 ^^^^^^
 The `from` command is used to specify the commit to initialize
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 1af85d404f..9ce5b8aaee 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -22,7 +22,8 @@ SYNOPSIS
 		   [--rfc] [--subject-prefix=Subject-Prefix]
 		   [(--reroll-count|-v) <n>]
 		   [--to=<email>] [--cc=<email>]
-		   [--[no-]cover-letter] [--quiet] [--notes[=<ref>]]
+		   [--[no-]cover-letter] [--quiet]
+		   [--no-notes | --notes[=<ref>]]
 		   [--interdiff=<previous>]
 		   [--range-diff=<previous> [--creation-factor=<percent>]]
 		   [--progress]
@@ -263,6 +264,7 @@ material (this may change in the future).
 	for details.
 
 --notes[=<ref>]::
+--no-notes::
 	Append the notes (see linkgit:git-notes[1]) for the commit
 	after the three-dash line.
 +
@@ -273,6 +275,9 @@ these explanations after `format-patch` has run but before sending,
 keeping them as Git notes allows them to be maintained between versions
 of the patch series (but see the discussion of the `notes.rewrite`
 configuration options in linkgit:git-notes[1] to use this workflow).
++
+The default is `--no-notes`, unless the `format.notes` configuration is
+set.
 
 --[no-]signature=<signature>::
 	Add a signature to each message produced. Per RFC 3676 the signature
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 6294dbc09d..c01cfa6595 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -100,6 +100,10 @@ commit or stash your changes before running 'git merge'.
 'git merge --abort' is equivalent to 'git reset --merge' when
 `MERGE_HEAD` is present.
 
+--quit::
+	Forget about the current merge in progress. Leave the index
+	and the working tree as-is.
+
 --continue::
 	After a 'git merge' stops due to conflicts you can conclude the
 	merge by running 'git merge --continue' (see "HOW TO RESOLVE
diff --git a/Documentation/git-mergetool--lib.txt b/Documentation/git-mergetool--lib.txt
index 055550b2bc..4da9d24096 100644
--- a/Documentation/git-mergetool--lib.txt
+++ b/Documentation/git-mergetool--lib.txt
@@ -28,7 +28,9 @@ to define the operation mode for the functions listed below.
 FUNCTIONS
 ---------
 get_merge_tool::
-	returns a merge tool.
+	returns a merge tool. the return code is 1 if we returned a guessed
+	merge tool, else 0. '$GIT_MERGETOOL_GUI' may be set to 'true' to
+	search for the appropriate guitool.
 
 get_merge_tool_cmd::
 	returns the custom command for a merge tool.
diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 0c7975a050..6b14702e78 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -83,7 +83,9 @@ success of the resolution after the custom tool has exited.
 --gui::
 	When 'git-mergetool' is invoked with the `-g` or `--gui` option
 	the default merge tool will be read from the configured
-	`merge.guitool` variable instead of `merge.tool`.
+	`merge.guitool` variable instead of `merge.tool`. If
+	`merge.guitool` is not set, we will fallback to the tool
+	configured under `merge.tool`.
 
 --no-gui::
 	This overrides a previous `-g` or `--gui` setting and reads the
diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt
index 118d9d86f7..a5e9501a0a 100644
--- a/Documentation/git-pull.txt
+++ b/Documentation/git-pull.txt
@@ -112,8 +112,9 @@ When set to `merges`, rebase using `git rebase --rebase-merges` so that
 the local merge commits are included in the rebase (see
 linkgit:git-rebase[1] for details).
 +
-When set to preserve, rebase with the `--preserve-merges` option passed
-to `git rebase` so that locally created merge commits will not be flattened.
+When set to `preserve` (deprecated in favor of `merges`), rebase with the
+`--preserve-merges` option passed to `git rebase` so that locally created
+merge commits will not be flattened.
 +
 When false, merge the current branch into the upstream branch.
 +
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index f5e6ae3907..5e4e927647 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -675,7 +675,8 @@ $ git rebase -i HEAD~5
 
 And move the first patch to the end of the list.
 
-You might want to preserve merges, if you have a history like this:
+You might want to recreate merge commits, e.g. if you have a history
+like this:
 
 ------------------
            X
@@ -689,7 +690,7 @@ Suppose you want to rebase the side branch starting at "A" to "Q". Make
 sure that the current HEAD is "B", and call
 
 -----------------------------
-$ git rebase -i -p --onto Q O
+$ git rebase -i -r --onto Q O
 -----------------------------
 
 Reordering and editing commits usually creates untested intermediate
diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index 1afe9fc858..a861934c69 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt
@@ -278,6 +278,14 @@ must be used for each option.
 Automating
 ~~~~~~~~~~
 
+--no-[to|cc|bcc]::
+	Clears any list of "To:", "Cc:", "Bcc:" addresses previously
+	set via config.
+
+--no-identity::
+	Clears the previously read value of `sendemail.identity` set
+	via config, if any.
+
 --to-cmd=<command>::
 	Specify a command to execute once per patch file which
 	should generate patch file specific "To:" entries.
diff --git a/Documentation/git-update-server-info.txt b/Documentation/git-update-server-info.txt
index bd0e36492f..969bb2e15f 100644
--- a/Documentation/git-update-server-info.txt
+++ b/Documentation/git-update-server-info.txt
@@ -9,7 +9,7 @@ git-update-server-info - Update auxiliary info file to help dumb servers
 SYNOPSIS
 --------
 [verse]
-'git update-server-info' [--force]
+'git update-server-info'
 
 DESCRIPTION
 -----------
@@ -19,15 +19,6 @@ $GIT_OBJECT_DIRECTORY/info directories to help clients discover
 what references and packs the server has.  This command
 generates such auxiliary files.
 
-
-OPTIONS
--------
-
--f::
---force::
-	Update the info files from scratch.
-
-
 OUTPUT
 ------
 
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 6d1f2fd9ae..6ddc1e2ca6 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -660,6 +660,54 @@ of clones and fetches.
 	When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
 	data (that is, only dump info lines and headers).
 
+`GIT_TRACE2`::
+	Enables more detailed trace messages from the "trace2" library.
+	Output from `GIT_TRACE2` is a simple text-based format for human
+	readability.
++
+If this variable is set to "1", "2" or "true" (comparison
+is case insensitive), trace messages will be printed to
+stderr.
++
+If the variable is set to an integer value greater than 2
+and lower than 10 (strictly) then Git will interpret this
+value as an open file descriptor and will try to write the
+trace messages into this file descriptor.
++
+Alternatively, if the variable is set to an absolute path
+(starting with a '/' character), Git will interpret this
+as a file path and will try to append the trace messages
+to it.  If the path already exists and is a directory, the
+trace messages will be written to files (one per process)
+in that directory, named according to the last component
+of the SID and an optional counter (to avoid filename
+collisions).
++
+In addition, if the variable is set to
+`af_unix:[<socket_type>:]<absolute-pathname>`, Git will try
+to open the path as a Unix Domain Socket.  The socket type
+can be either `stream` or `dgram`.
++
+Unsetting the variable, or setting it to empty, "0" or
+"false" (case insensitive) disables trace messages.
++
+See link:technical/api-trace2.html[Trace2 documentation]
+for full details.
+
+
+`GIT_TRACE2_EVENT`::
+	This setting writes a JSON-based format that is suited for machine
+	interpretation.
+	See `GIT_TRACE2` for available trace output options and
+	link:technical/api-trace2.html[Trace2 documentation] for full details.
+
+`GIT_TRACE2_PERF`::
+	In addition to the text-based messages available in `GIT_TRACE2`, this
+	setting writes a column-based format for understanding nesting
+	regions.
+	See `GIT_TRACE2` for available trace output options and
+	link:technical/api-trace2.html[Trace2 documentation] for full details.
+
 `GIT_REDACT_COOKIES`::
 	This can be set to a comma-separated list of strings. When a curl trace
 	is enabled (see `GIT_TRACE_CURL` above), whenever a "Cookies:" header
diff --git a/Documentation/gitsubmodules.txt b/Documentation/gitsubmodules.txt
index 57999e9f36..0a890205b8 100644
--- a/Documentation/gitsubmodules.txt
+++ b/Documentation/gitsubmodules.txt
@@ -169,15 +169,15 @@ ACTIVE SUBMODULES
 
 A submodule is considered active,
 
-  a. if `submodule.<name>.active` is set to `true`
+  1. if `submodule.<name>.active` is set to `true`
 +
 or
 
-  b. if the submodule's path matches the pathspec in `submodule.active`
+  2. if the submodule's path matches the pathspec in `submodule.active`
 +
 or
 
-  c. if `submodule.<name>.url` is set.
+  3. if `submodule.<name>.url` is set.
 
 and these are evaluated in this order.
 
@@ -193,11 +193,11 @@ For example:
     url = https://example.org/baz
 
 In the above config only the submodule 'bar' and 'baz' are active,
-'bar' due to (a) and 'baz' due to (c). 'foo' is inactive because
-(a) takes precedence over (c)
+'bar' due to (1) and 'baz' due to (3). 'foo' is inactive because
+(1) takes precedence over (3)
 
-Note that (c) is a historical artefact and will be ignored if the
-(a) and (b) specify that the submodule is not active. In other words,
+Note that (3) is a historical artefact and will be ignored if the
+(1) and (2) specify that the submodule is not active. In other words,
 if we have a `submodule.<name>.active` set to `false` or if the
 submodule's path is excluded in the pathspec in `submodule.active`, the
 url doesn't matter whether it is present or not. This is illustrated in
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index ddbc1de43f..71a1fcc093 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -725,9 +725,6 @@ specification contained in the blob (or blob-expression) '<blob-ish>'
 to omit blobs that would not be not required for a sparse checkout on
 the requested refs.
 +
-The form '--filter=sparse:path=<path>' similarly uses a sparse-checkout
-specification contained in <path>.
-+
 The form '--filter=tree:<depth>' omits all blobs and trees whose depth
 from the root tree is >= <depth> (minimum depth if an object is located
 at multiple depths in the commits traversed). <depth>=0 will not include
@@ -737,6 +734,10 @@ tree and blobs which are referenced directly by a commit reachable from
 <commit> or an explicitly-given object. <depth>=2 is like <depth>=1
 while also including trees and blobs one more level removed from an
 explicitly-given commit or tree.
++
+Note that the form '--filter=sparse:path=<path>' that wants to read
+from an arbitrary path on the filesystem has been dropped for security
+reasons.
 
 --no-filter::
 	Turn off any previous `--filter=` argument.
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 9e585b8e79..23c3cc7a37 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -23,7 +23,7 @@ formats in the future.  This might be used to define a binary format,
 for example.
 
 Trace2 is controlled using `trace2.*` config values in the system and
-global config files and `GIT_TR2*` environment variables.  Trace2 does
+global config files and `GIT_TRACE2*` environment variables.  Trace2 does
 not read from repo local or worktree config files or respect `-c`
 command line config settings.
 
@@ -42,7 +42,7 @@ config setting.
 For example
 
 ------------
-$ export GIT_TR2=~/log.normal
+$ export GIT_TRACE2=~/log.normal
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
@@ -71,13 +71,13 @@ $ cat ~/log.normal
 The performance format target (PERF) is a column-based format to
 replace GIT_TRACE_PERFORMANCE and is suitable for development and
 testing, possibly to complement tools like gprof.  This format is
-enabled with the `GIT_TR2_PERF` environment variable or the
+enabled with the `GIT_TRACE2_PERF` environment variable or the
 `trace2.perfTarget` system or global config setting.
 
 For example
 
 ------------
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
@@ -104,14 +104,14 @@ $ cat ~/log.perf
 === The Event Format Target
 
 The event format target is a JSON-based format of event data suitable
-for telemetry analysis.  This format is enabled with the `GIT_TR2_EVENT`
+for telemetry analysis.  This format is enabled with the `GIT_TRACE2_EVENT`
 environment variable or the `trace2.eventTarget` system or global config
 setting.
 
 For example
 
 ------------
-$ export GIT_TR2_EVENT=~/log.event
+$ export GIT_TRACE2_EVENT=~/log.event
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
@@ -273,7 +273,7 @@ significantly affects program performance or behavior, such as
 	Emits a "def_param" messages for "important" configuration
 	settings.
 +
-The environment variable `GIT_TR2_CONFIG_PARAMS` or the `trace2.configParams`
+The environment variable `GIT_TRACE2_CONFIG_PARAMS` or the `trace2.configParams`
 config value can be set to a
 list of patterns of important configuration settings, for example:
 `core.*,remote.*.url`.  This function will iterate over all config
@@ -465,7 +465,7 @@ Events are written as lines of the form:
 Note that this may contain embedded LF or CRLF characters that are
 not escaped, so the event may spill across multiple lines.
 
-If `GIT_TR2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
+If `GIT_TRACE2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
 and `line` fields are omitted.
 
 This target is intended to be more of a summary (like GIT_TRACE) and
@@ -533,7 +533,7 @@ This field is in anticipation of in-proc submodules in the future.
 15:33:33.532712 wt-status.c:2331                  | d0 | main                     | region_leave | r1  |  0.127568 |  0.001504 | status     | label:print
 ------------
 
-If `GIT_TR2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
+If `GIT_TRACE2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
 and `line` fields are omitted.
 
 ------------
@@ -598,7 +598,7 @@ The following key/value pairs are common to all events:
 `"repo":<repo-id>`::
 	when present, is the integer repo-id as described previously.
 
-If `GIT_TR2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
+If `GIT_TRACE2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
 and `line` fields are omitted from all events and the `time` field is
 only present on the "start" and "atexit" events.
 
@@ -911,7 +911,7 @@ visited.
 The `category` field may be used in a future enhancement to
 do category-based filtering.
 +
-`GIT_TR2_EVENT_NESTING` or `trace2.eventNesting` can be used to
+`GIT_TRACE2_EVENT_NESTING` or `trace2.eventNesting` can be used to
 filter deeply nested regions and data events.  It defaults to "2".
 
 `"region_leave"`::
@@ -1039,8 +1039,8 @@ rev-list, and gc.  This example also shows that fetch took
 5.199 seconds and of that 4.932 was in ssh.
 +
 ----------------
-$ export GIT_TR2_BRIEF=1
-$ export GIT_TR2=~/log.normal
+$ export GIT_TRACE2_BRIEF=1
+$ export GIT_TRACE2=~/log.normal
 $ git fetch origin
 ...
 ----------------
@@ -1075,8 +1075,8 @@ its name as "gc", it also reports the hierarchy as "fetch/gc".
 indented for clarity.)
 +
 ----------------
-$ export GIT_TR2_BRIEF=1
-$ export GIT_TR2=~/log.normal
+$ export GIT_TRACE2_BRIEF=1
+$ export GIT_TRACE2=~/log.normal
 $ git fetch origin
 ...
 ----------------
@@ -1134,8 +1134,8 @@ In this example, scanning for untracked files ran from +0.012568 to
 +0.027149 (since the process started) and took 0.014581 seconds.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 
@@ -1180,8 +1180,8 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 We can further investigate the time spent scanning for untracked files.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 $ cat ~/log.perf
@@ -1236,8 +1236,8 @@ int read_index_from(struct index_state *istate, const char *path,
 This example shows that the index contained 3552 entries.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 $ cat ~/log.perf
@@ -1310,8 +1310,8 @@ Data events are tagged with the active thread name.  They are used
 to report the per-thread parameters.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 $ cat ~/log.perf