From c8bae7493d2f2910b57f13ded012e86bdcfb0532 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 16:47:53 +0200
Subject: Adding upstream version 1:2.39.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 Documentation/git-format-patch.txt | 772 +++++++++++++++++++++++++++++++++++++
 1 file changed, 772 insertions(+)
 create mode 100644 Documentation/git-format-patch.txt

(limited to 'Documentation/git-format-patch.txt')

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
new file mode 100644
index 0000000..dfcc7da
--- /dev/null
+++ b/Documentation/git-format-patch.txt
@@ -0,0 +1,772 @@
+git-format-patch(1)
+===================
+
+NAME
+----
+git-format-patch - Prepare patches for e-mail submission
+
+
+SYNOPSIS
+--------
+[verse]
+'git format-patch' [-k] [(-o|--output-directory) <dir> | --stdout]
+		   [--no-thread | --thread[=<style>]]
+		   [(--attach|--inline)[=<boundary>] | --no-attach]
+		   [-s | --signoff]
+		   [--signature=<signature> | --no-signature]
+		   [--signature-file=<file>]
+		   [-n | --numbered | -N | --no-numbered]
+		   [--start-number <n>] [--numbered-files]
+		   [--in-reply-to=<message id>] [--suffix=.<sfx>]
+		   [--ignore-if-in-upstream] [--always]
+		   [--cover-from-description=<mode>]
+		   [--rfc] [--subject-prefix=<subject prefix>]
+		   [(--reroll-count|-v) <n>]
+		   [--to=<email>] [--cc=<email>]
+		   [--[no-]cover-letter] [--quiet]
+		   [--[no-]encode-email-headers]
+		   [--no-notes | --notes[=<ref>]]
+		   [--interdiff=<previous>]
+		   [--range-diff=<previous> [--creation-factor=<percent>]]
+		   [--filename-max-length=<n>]
+		   [--progress]
+		   [<common diff options>]
+		   [ <since> | <revision range> ]
+
+DESCRIPTION
+-----------
+
+Prepare each non-merge commit with its "patch" in
+one "message" per commit, formatted to resemble a UNIX mailbox.
+The output of this command is convenient for e-mail submission or
+for use with 'git am'.
+
+A "message" generated by the command consists of three parts:
+
+* A brief metadata header that begins with `From <commit>`
+  with a fixed `Mon Sep 17 00:00:00 2001` datestamp to help programs
+  like "file(1)" to recognize that the file is an output from this
+  command, fields that record the author identity, the author date,
+  and the title of the change (taken from the first paragraph of the
+  commit log message).
+
+* The second and subsequent paragraphs of the commit log message.
+
+* The "patch", which is the "diff -p --stat" output (see
+  linkgit:git-diff[1]) between the commit and its parent.
+
+The log message and the patch is separated by a line with a
+three-dash line.
+
+There are two ways to specify which commits to operate on.
+
+1. A single commit, <since>, specifies that the commits leading
+   to the tip of the current branch that are not in the history
+   that leads to the <since> to be output.
+
+2. Generic <revision range> expression (see "SPECIFYING
+   REVISIONS" section in linkgit:gitrevisions[7]) means the
+   commits in the specified range.
+
+The first rule takes precedence in the case of a single <commit>.  To
+apply the second rule, i.e., format everything since the beginning of
+history up until <commit>, use the `--root` option: `git format-patch
+--root <commit>`.  If you want to format only <commit> itself, you
+can do this with `git format-patch -1 <commit>`.
+
+By default, each output file is numbered sequentially from 1, and uses the
+first line of the commit message (massaged for pathname safety) as
+the filename. With the `--numbered-files` option, the output file names
+will only be numbers, without the first line of the commit appended.
+The names of the output files are printed to standard
+output, unless the `--stdout` option is specified.
+
+If `-o` is specified, output files are created in <dir>.  Otherwise
+they are created in the current working directory. The default path
+can be set with the `format.outputDirectory` configuration option.
+The `-o` option takes precedence over `format.outputDirectory`.
+To store patches in the current working directory even when
+`format.outputDirectory` points elsewhere, use `-o .`. All directory
+components will be created.
+
+By default, the subject of a single patch is "[PATCH] " followed by
+the concatenation of lines from the commit message up to the first blank
+line (see the DISCUSSION section of linkgit:git-commit[1]).
+
+When multiple patches are output, the subject prefix will instead be
+"[PATCH n/m] ".  To force 1/1 to be added for a single patch, use `-n`.
+To omit patch numbers from the subject, use `-N`.
+
+If given `--thread`, `git-format-patch` will generate `In-Reply-To` and
+`References` headers to make the second and subsequent patch mails appear
+as replies to the first mail; this also generates a `Message-Id` header to
+reference.
+
+OPTIONS
+-------
+:git-format-patch: 1
+include::diff-options.txt[]
+
+-<n>::
+	Prepare patches from the topmost <n> commits.
+
+-o <dir>::
+--output-directory <dir>::
+	Use <dir> to store the resulting files, instead of the
+	current working directory.
+
+-n::
+--numbered::
+	Name output in '[PATCH n/m]' format, even with a single patch.
+
+-N::
+--no-numbered::
+	Name output in '[PATCH]' format.
+
+--start-number <n>::
+	Start numbering the patches at <n> instead of 1.
+
+--numbered-files::
+	Output file names will be a simple number sequence
+	without the default first line of the commit appended.
+
+-k::
+--keep-subject::
+	Do not strip/add '[PATCH]' from the first line of the
+	commit log message.
+
+-s::
+--signoff::
+	Add a `Signed-off-by` trailer to the commit message, using
+	the committer identity of yourself.
+	See the signoff option in linkgit:git-commit[1] for more information.
+
+--stdout::
+	Print all commits to the standard output in mbox format,
+	instead of creating a file for each one.
+
+--attach[=<boundary>]::
+	Create multipart/mixed attachment, the first part of
+	which is the commit message and the patch itself in the
+	second part, with `Content-Disposition: attachment`.
+
+--no-attach::
+	Disable the creation of an attachment, overriding the
+	configuration setting.
+
+--inline[=<boundary>]::
+	Create multipart/mixed attachment, the first part of
+	which is the commit message and the patch itself in the
+	second part, with `Content-Disposition: inline`.
+
+--thread[=<style>]::
+--no-thread::
+	Controls addition of `In-Reply-To` and `References` headers to
+	make the second and subsequent mails appear as replies to the
+	first.  Also controls generation of the `Message-Id` header to
+	reference.
++
+The optional <style> argument can be either `shallow` or `deep`.
+'shallow' threading makes every mail a reply to the head of the
+series, where the head is chosen from the cover letter, the
+`--in-reply-to`, and the first patch mail, in this order.  'deep'
+threading makes every mail a reply to the previous one.
++
+The default is `--no-thread`, unless the `format.thread` configuration
+is set.  If `--thread` is specified without a style, it defaults to the
+style specified by `format.thread` if any, or else `shallow`.
++
+Beware that the default for 'git send-email' is to thread emails
+itself.  If you want `git format-patch` to take care of threading, you
+will want to ensure that threading is disabled for `git send-email`.
+
+--in-reply-to=<message id>::
+	Make the first mail (or all the mails with `--no-thread`) appear as a
+	reply to the given <message id>, which avoids breaking threads to
+	provide a new patch series.
+
+--ignore-if-in-upstream::
+	Do not include a patch that matches a commit in
+	<until>..<since>.  This will examine all patches reachable
+	from <since> but not from <until> and compare them with the
+	patches being generated, and any patch that matches is
+	ignored.
+
+--always::
+	Include patches for commits that do not introduce any change,
+	which are omitted by default.
+
+--cover-from-description=<mode>::
+	Controls which parts of the cover letter will be automatically
+	populated using the branch's description.
++
+If `<mode>` is `message` or `default`, the cover letter subject will be
+populated with placeholder text. The body of the cover letter will be
+populated with the branch's description. This is the default mode when
+no configuration nor command line option is specified.
++
+If `<mode>` is `subject`, the first paragraph of the branch description will
+populate the cover letter subject. The remainder of the description will
+populate the body of the cover letter.
++
+If `<mode>` is `auto`, if the first paragraph of the branch description
+is greater than 100 bytes, then the mode will be `message`, otherwise
+`subject` will be used.
++
+If `<mode>` is `none`, both the cover letter subject and body will be
+populated with placeholder text.
+
+--subject-prefix=<subject prefix>::
+	Instead of the standard '[PATCH]' prefix in the subject
+	line, instead use '[<subject prefix>]'. This
+	allows for useful naming of a patch series, and can be
+	combined with the `--numbered` option.
+
+--filename-max-length=<n>::
+	Instead of the standard 64 bytes, chomp the generated output
+	filenames at around '<n>' bytes (too short a value will be
+	silently raised to a reasonable length).  Defaults to the
+	value of the `format.filenameMaxLength` configuration
+	variable, or 64 if unconfigured.
+
+--rfc::
+	Alias for `--subject-prefix="RFC PATCH"`. RFC means "Request For
+	Comments"; use this when sending an experimental patch for
+	discussion rather than application.
+
+-v <n>::
+--reroll-count=<n>::
+	Mark the series as the <n>-th iteration of the topic. The
+	output filenames have `v<n>` prepended to them, and the
+	subject prefix ("PATCH" by default, but configurable via the
+	`--subject-prefix` option) has ` v<n>` appended to it.  E.g.
+	`--reroll-count=4` may produce `v4-0001-add-makefile.patch`
+	file that has "Subject: [PATCH v4 1/20] Add makefile" in it.
+	`<n>` does not have to be an integer (e.g. "--reroll-count=4.4",
+	or "--reroll-count=4rev2" are allowed), but the downside of
+	using such a reroll-count is that the range-diff/interdiff
+	with the previous version does not state exactly which
+	version the new interation is compared against.
+
+--to=<email>::
+	Add a `To:` header to the email headers. This is in addition
+	to any configured headers, and may be used multiple times.
+	The negated form `--no-to` discards all `To:` headers added so
+	far (from config or command line).
+
+--cc=<email>::
+	Add a `Cc:` header to the email headers. This is in addition
+	to any configured headers, and may be used multiple times.
+	The negated form `--no-cc` discards all `Cc:` headers added so
+	far (from config or command line).
+
+--from::
+--from=<ident>::
+	Use `ident` in the `From:` header of each commit email. If the
+	author ident of the commit is not textually identical to the
+	provided `ident`, place a `From:` header in the body of the
+	message with the original author. If no `ident` is given, use
+	the committer ident.
++
+Note that this option is only useful if you are actually sending the
+emails and want to identify yourself as the sender, but retain the
+original author (and `git am` will correctly pick up the in-body
+header). Note also that `git send-email` already handles this
+transformation for you, and this option should not be used if you are
+feeding the result to `git send-email`.
+
+--[no-]force-in-body-from::
+	With the e-mail sender specified via the `--from` option, by
+	default, an in-body "From:" to identify the real author of
+	the commit is added at the top of the commit log message if
+	the sender is different from the author.  With this option,
+	the in-body "From:" is added even when the sender and the
+	author have the same name and address, which may help if the
+	mailing list software mangles the sender's identity.
+	Defaults to the value of the `format.forceInBodyFrom`
+	configuration variable.
+
+--add-header=<header>::
+	Add an arbitrary header to the email headers.  This is in addition
+	to any configured headers, and may be used multiple times.
+	For example, `--add-header="Organization: git-foo"`.
+	The negated form `--no-add-header` discards *all* (`To:`,
+	`Cc:`, and custom) headers added so far from config or command
+	line.
+
+--[no-]cover-letter::
+	In addition to the patches, generate a cover letter file
+	containing the branch description, shortlog and the overall diffstat.  You can
+	fill in a description in the file before sending it out.
+
+--encode-email-headers::
+--no-encode-email-headers::
+	Encode email headers that have non-ASCII characters with
+	"Q-encoding" (described in RFC 2047), instead of outputting the
+	headers verbatim. Defaults to the value of the
+	`format.encodeEmailHeaders` configuration variable.
+
+--interdiff=<previous>::
+	As a reviewer aid, insert an interdiff into the cover letter,
+	or as commentary of the lone patch of a 1-patch series, showing
+	the differences between the previous version of the patch series and
+	the series currently being formatted. `previous` is a single revision
+	naming the tip of the previous series which shares a common base with
+	the series being formatted (for example `git format-patch
+	--cover-letter --interdiff=feature/v1 -3 feature/v2`).
+
+--range-diff=<previous>::
+	As a reviewer aid, insert a range-diff (see linkgit:git-range-diff[1])
+	into the cover letter, or as commentary of the lone patch of a
+	1-patch series, showing the differences between the previous
+	version of the patch series and the series currently being formatted.
+	`previous` can be a single revision naming the tip of the previous
+	series if it shares a common base with the series being formatted (for
+	example `git format-patch --cover-letter --range-diff=feature/v1 -3
+	feature/v2`), or a revision range if the two versions of the series are
+	disjoint (for example `git format-patch --cover-letter
+	--range-diff=feature/v1~3..feature/v1 -3 feature/v2`).
++
+Note that diff options passed to the command affect how the primary
+product of `format-patch` is generated, and they are not passed to
+the underlying `range-diff` machinery used to generate the cover-letter
+material (this may change in the future).
+
+--creation-factor=<percent>::
+	Used with `--range-diff`, tweak the heuristic which matches up commits
+	between the previous and current series of patches by adjusting the
+	creation/deletion cost fudge factor. See linkgit:git-range-diff[1])
+	for details.
+
+--notes[=<ref>]::
+--no-notes::
+	Append the notes (see linkgit:git-notes[1]) for the commit
+	after the three-dash line.
++
+The expected use case of this is to write supporting explanation for
+the commit that does not belong to the commit log message proper,
+and include it with the patch submission. While one can simply write
+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
+	is separated from the body by a line with '-- ' on it. If the
+	signature option is omitted the signature defaults to the Git version
+	number.
+
+--signature-file=<file>::
+	Works just like --signature except the signature is read from a file.
+
+--suffix=.<sfx>::
+	Instead of using `.patch` as the suffix for generated
+	filenames, use specified suffix.  A common alternative is
+	`--suffix=.txt`.  Leaving this empty will remove the `.patch`
+	suffix.
++
+Note that the leading character does not have to be a dot; for example,
+you can use `--suffix=-patch` to get `0001-description-of-my-change-patch`.
+
+-q::
+--quiet::
+	Do not print the names of the generated files to standard output.
+
+--no-binary::
+	Do not output contents of changes in binary files, instead
+	display a notice that those files changed.  Patches generated
+	using this option cannot be applied properly, but they are
+	still useful for code review.
+
+--zero-commit::
+  Output an all-zero hash in each patch's From header instead
+  of the hash of the commit.
+
+--[no-]base[=<commit>]::
+	Record the base tree information to identify the state the
+	patch series applies to.  See the BASE TREE INFORMATION section
+	below for details. If <commit> is "auto", a base commit is
+	automatically chosen. The `--no-base` option overrides a
+	`format.useAutoBase` configuration.
+
+--root::
+	Treat the revision argument as a <revision range>, even if it
+	is just a single commit (that would normally be treated as a
+	<since>).  Note that root commits included in the specified
+	range are always formatted as creation patches, independently
+	of this flag.
+
+--progress::
+	Show progress reports on stderr as patches are generated.
+
+CONFIGURATION
+-------------
+You can specify extra mail header lines to be added to each message,
+defaults for the subject prefix and file suffix, number patches when
+outputting more than one patch, add "To:" or "Cc:" headers, configure
+attachments, change the patch output directory, and sign off patches
+with configuration variables.
+
+------------
+[format]
+	headers = "Organization: git-foo\n"
+	subjectPrefix = CHANGE
+	suffix = .txt
+	numbered = auto
+	to = <email>
+	cc = <email>
+	attach [ = mime-boundary-string ]
+	signOff = true
+	outputDirectory = <directory>
+	coverLetter = auto
+	coverFromDescription = auto
+------------
+
+
+DISCUSSION
+----------
+
+The patch produced by 'git format-patch' is in UNIX mailbox format,
+with a fixed "magic" time stamp to indicate that the file is output
+from format-patch rather than a real mailbox, like so:
+
+------------
+From 8f72bad1baf19a53459661343e21d6491c3908d3 Mon Sep 17 00:00:00 2001
+From: Tony Luck <tony.luck@intel.com>
+Date: Tue, 13 Jul 2010 11:42:54 -0700
+Subject: [PATCH] =?UTF-8?q?[IA64]=20Put=20ia64=20config=20files=20on=20the=20?=
+ =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig=20diet?=
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+arch/arm config files were slimmed down using a python script
+(See commit c2330e286f68f1c408b4aa6515ba49d57f05beae comment)
+
+Do the same for ia64 so we can have sleek & trim looking
+...
+------------
+
+Typically it will be placed in a MUA's drafts folder, edited to add
+timely commentary that should not go in the changelog after the three
+dashes, and then sent as a message whose body, in our example, starts
+with "arch/arm config files were...".  On the receiving end, readers
+can save interesting patches in a UNIX mailbox and apply them with
+linkgit:git-am[1].
+
+When a patch is part of an ongoing discussion, the patch generated by
+'git format-patch' can be tweaked to take advantage of the 'git am
+--scissors' feature.  After your response to the discussion comes a
+line that consists solely of "`-- >8 --`" (scissors and perforation),
+followed by the patch with unnecessary header fields removed:
+
+------------
+...
+> So we should do such-and-such.
+
+Makes sense to me.  How about this patch?
+
+-- >8 --
+Subject: [IA64] Put ia64 config files on the Uwe Kleine-König diet
+
+arch/arm config files were slimmed down using a python script
+...
+------------
+
+When sending a patch this way, most often you are sending your own
+patch, so in addition to the "`From $SHA1 $magic_timestamp`" marker you
+should omit `From:` and `Date:` lines from the patch file.  The patch
+title is likely to be different from the subject of the discussion the
+patch is in response to, so it is likely that you would want to keep
+the Subject: line, like the example above.
+
+Checking for patch corruption
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Many mailers if not set up properly will corrupt whitespace.  Here are
+two common types of corruption:
+
+* Empty context lines that do not have _any_ whitespace.
+
+* Non-empty context lines that have one extra whitespace at the
+  beginning.
+
+One way to test if your MUA is set up correctly is:
+
+* Send the patch to yourself, exactly the way you would, except
+  with To: and Cc: lines that do not contain the list and
+  maintainer address.
+
+* Save that patch to a file in UNIX mailbox format.  Call it a.patch,
+  say.
+
+* Apply it:
+
+    $ git fetch <project> master:test-apply
+    $ git switch test-apply
+    $ git restore --source=HEAD --staged --worktree :/
+    $ git am a.patch
+
+If it does not apply correctly, there can be various reasons.
+
+* The patch itself does not apply cleanly.  That is _bad_ but
+  does not have much to do with your MUA.  You might want to rebase
+  the patch with linkgit:git-rebase[1] before regenerating it in
+  this case.
+
+* The MUA corrupted your patch; "am" would complain that
+  the patch does not apply.  Look in the .git/rebase-apply/ subdirectory and
+  see what 'patch' file contains and check for the common
+  corruption patterns mentioned above.
+
+* While at it, check the 'info' and 'final-commit' files as well.
+  If what is in 'final-commit' is not exactly what you would want to
+  see in the commit log message, it is very likely that the
+  receiver would end up hand editing the log message when applying
+  your patch.  Things like "Hi, this is my first patch.\n" in the
+  patch e-mail should come after the three-dash line that signals
+  the end of the commit message.
+
+MUA-SPECIFIC HINTS
+------------------
+Here are some hints on how to successfully submit patches inline using
+various mailers.
+
+GMail
+~~~~~
+GMail does not have any way to turn off line wrapping in the web
+interface, so it will mangle any emails that you send.  You can however
+use "git send-email" and send your patches through the GMail SMTP server, or
+use any IMAP email client to connect to the google IMAP server and forward
+the emails through that.
+
+For hints on using 'git send-email' to send your patches through the
+GMail SMTP server, see the EXAMPLE section of linkgit:git-send-email[1].
+
+For hints on submission using the IMAP interface, see the EXAMPLE
+section of linkgit:git-imap-send[1].
+
+Thunderbird
+~~~~~~~~~~~
+By default, Thunderbird will both wrap emails as well as flag
+them as being 'format=flowed', both of which will make the
+resulting email unusable by Git.
+
+There are three different approaches: use an add-on to turn off line wraps,
+configure Thunderbird to not mangle patches, or use
+an external editor to keep Thunderbird from mangling the patches.
+
+Approach #1 (add-on)
+^^^^^^^^^^^^^^^^^^^^
+
+Install the Toggle Word Wrap add-on that is available from
+https://addons.mozilla.org/thunderbird/addon/toggle-word-wrap/
+It adds a menu entry "Enable Word Wrap" in the composer's "Options" menu
+that you can tick off. Now you can compose the message as you otherwise do
+(cut + paste, 'git format-patch' | 'git imap-send', etc), but you have to
+insert line breaks manually in any text that you type.
+
+Approach #2 (configuration)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Three steps:
+
+1. Configure your mail server composition as plain text:
+   Edit...Account Settings...Composition & Addressing,
+   uncheck "Compose Messages in HTML".
+
+2. Configure your general composition window to not wrap.
++
+In Thunderbird 2:
+Edit..Preferences..Composition, wrap plain text messages at 0
++
+In Thunderbird 3:
+Edit..Preferences..Advanced..Config Editor.  Search for
+"mail.wrap_long_lines".
+Toggle it to make sure it is set to `false`. Also, search for
+"mailnews.wraplength" and set the value to 0.
+
+3. Disable the use of format=flowed:
+   Edit..Preferences..Advanced..Config Editor.  Search for
+   "mailnews.send_plaintext_flowed".
+   Toggle it to make sure it is set to `false`.
+
+After that is done, you should be able to compose email as you
+otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
+and the patches will not be mangled.
+
+Approach #3 (external editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following Thunderbird extensions are needed:
+AboutConfig from http://aboutconfig.mozdev.org/ and
+External Editor from http://globs.org/articles.php?lng=en&pg=8
+
+1. Prepare the patch as a text file using your method of choice.
+
+2. Before opening a compose window, use Edit->Account Settings to
+   uncheck the "Compose messages in HTML format" setting in the
+   "Composition & Addressing" panel of the account to be used to
+   send the patch.
+
+3. In the main Thunderbird window, 'before' you open the compose
+   window for the patch, use Tools->about:config to set the
+   following to the indicated values:
++
+----------
+	mailnews.send_plaintext_flowed  => false
+	mailnews.wraplength             => 0
+----------
+
+4. Open a compose window and click the external editor icon.
+
+5. In the external editor window, read in the patch file and exit
+   the editor normally.
+
+Side note: it may be possible to do step 2 with
+about:config and the following settings but no one's tried yet.
+
+----------
+	mail.html_compose                       => false
+	mail.identity.default.compose_html      => false
+	mail.identity.id?.compose_html          => false
+----------
+
+There is a script in contrib/thunderbird-patch-inline which can help
+you include patches with Thunderbird in an easy way. To use it, do the
+steps above and then use the script as the external editor.
+
+KMail
+~~~~~
+This should help you to submit patches inline using KMail.
+
+1. Prepare the patch as a text file.
+
+2. Click on New Mail.
+
+3. Go under "Options" in the Composer window and be sure that
+   "Word wrap" is not set.
+
+4. Use Message -> Insert file... and insert the patch.
+
+5. Back in the compose window: add whatever other text you wish to the
+   message, complete the addressing and subject fields, and press send.
+
+BASE TREE INFORMATION
+---------------------
+
+The base tree information block is used for maintainers or third party
+testers to know the exact state the patch series applies to. It consists
+of the 'base commit', which is a well-known commit that is part of the
+stable part of the project history everybody else works off of, and zero
+or more 'prerequisite patches', which are well-known patches in flight
+that is not yet part of the 'base commit' that need to be applied on top
+of 'base commit' in topological order before the patches can be applied.
+
+The 'base commit' is shown as "base-commit: " followed by the 40-hex of
+the commit object name.  A 'prerequisite patch' is shown as
+"prerequisite-patch-id: " followed by the 40-hex 'patch id', which can
+be obtained by passing the patch through the `git patch-id --stable`
+command.
+
+Imagine that on top of the public commit P, you applied well-known
+patches X, Y and Z from somebody else, and then built your three-patch
+series A, B, C, the history would be like:
+
+................................................
+---P---X---Y---Z---A---B---C
+................................................
+
+With `git format-patch --base=P -3 C` (or variants thereof, e.g. with
+`--cover-letter` or using `Z..C` instead of `-3 C` to specify the
+range), the base tree information block is shown at the end of the
+first message the command outputs (either the first patch, or the
+cover letter), like this:
+
+------------
+base-commit: P
+prerequisite-patch-id: X
+prerequisite-patch-id: Y
+prerequisite-patch-id: Z
+------------
+
+For non-linear topology, such as
+
+................................................
+---P---X---A---M---C
+    \         /
+     Y---Z---B
+................................................
+
+You can also use `git format-patch --base=P -3 C` to generate patches
+for A, B and C, and the identifiers for P, X, Y, Z are appended at the
+end of the first message.
+
+If set `--base=auto` in cmdline, it will automatically compute
+the base commit as the merge base of tip commit of the remote-tracking
+branch and revision-range specified in cmdline.
+For a local branch, you need to make it to track a remote branch by `git branch
+--set-upstream-to` before using this option.
+
+EXAMPLES
+--------
+
+* Extract commits between revisions R1 and R2, and apply them on top of
+  the current branch using 'git am' to cherry-pick them:
++
+------------
+$ git format-patch -k --stdout R1..R2 | git am -3 -k
+------------
+
+* Extract all commits which are in the current branch but not in the
+  origin branch:
++
+------------
+$ git format-patch origin
+------------
++
+For each commit a separate file is created in the current directory.
+
+* Extract all commits that lead to 'origin' since the inception of the
+  project:
++
+------------
+$ git format-patch --root origin
+------------
+
+* The same as the previous one:
++
+------------
+$ git format-patch -M -B origin
+------------
++
+Additionally, it detects and handles renames and complete rewrites
+intelligently to produce a renaming patch.  A renaming patch reduces
+the amount of text output, and generally makes it easier to review.
+Note that non-Git "patch" programs won't understand renaming patches, so
+use it only when you know the recipient uses Git to apply your patch.
+
+* Extract three topmost commits from the current branch and format them
+  as e-mailable patches:
++
+------------
+$ git format-patch -3
+------------
+
+CAVEATS
+-------
+
+Note that `format-patch` will omit merge commits from the output, even
+if they are part of the requested range. A simple "patch" does not
+include enough information for the receiving end to reproduce the same
+merge commit.
+
+SEE ALSO
+--------
+linkgit:git-am[1], linkgit:git-send-email[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
-- 
cgit v1.2.3