GIT-FORMAT-PATCH(1)               Git Manual               GIT-FORMAT-PATCH(1)

NAME
       git-format-patch - Prepare patches for e-mail submission

SYNOPSIS
       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:

       o   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).

       o   The second and subsequent paragraphs of the commit log message.

       o   The "patch", which is the "diff -p --stat" output (see git-diff(1))
           between the commit and its parent.

       The log message and the patch are 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 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 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
       -p, --no-stat
           Generate plain patches without any diffstats.

       -U<n>, --unified=<n>
           Generate diffs with <n> lines of context instead of the usual
           three.

       --output=<file>
           Output to a specific file instead of stdout.

       --output-indicator-new=<char>, --output-indicator-old=<char>,
       --output-indicator-context=<char>
           Specify the character used to indicate new, old or context lines in
           the generated patch. Normally they are +, - and ' ' respectively.

       --indent-heuristic
           Enable the heuristic that shifts diff hunk boundaries to make
           patches easier to read. This is the default.

       --no-indent-heuristic
           Disable the indent heuristic.

       --minimal
           Spend extra time to make sure the smallest possible diff is
           produced.

       --patience
           Generate a diff using the "patience diff" algorithm.

       --histogram
           Generate a diff using the "histogram diff" algorithm.

       --anchored=<text>
           Generate a diff using the "anchored diff" algorithm.

           This option may be specified more than once.

           If a line exists in both the source and destination, exists only
           once, and starts with this text, this algorithm attempts to prevent
           it from appearing as a deletion or addition in the output. It uses
           the "patience diff" algorithm internally.

       --diff-algorithm={patience|minimal|histogram|myers}
           Choose a diff algorithm. The variants are as follows:

           default, myers
               The basic greedy diff algorithm. Currently, this is the
               default.

           minimal
               Spend extra time to make sure the smallest possible diff is
               produced.

           patience
               Use "patience diff" algorithm when generating patches.

           histogram
               This algorithm extends the patience algorithm to "support
               low-occurrence common elements".

           For instance, if you configured the diff.algorithm variable to a
           non-default value and want to use the default one, then you have to
           use --diff-algorithm=default option.

       --stat[=<width>[,<name-width>[,<count>]]]
           Generate a diffstat. By default, as much space as necessary will be
           used for the filename part, and the rest for the graph part.
           Maximum width defaults to terminal width, or 80 columns if not
           connected to a terminal, and can be overridden by <width>. The
           width of the filename part can be limited by giving another width
           <name-width> after a comma or by setting
           diff.statNameWidth=<width>. The width of the graph part can be
           limited by using --stat-graph-width=<width> or by setting
           diff.statGraphWidth=<width>. Using --stat or --stat-graph-width
           affects all commands generating a stat graph, while setting
           diff.statNameWidth or diff.statGraphWidth does not affect git
           format-patch. By giving a third parameter <count>, you can limit
           the output to the first <count> lines, followed by ... if there are
           more.

           These parameters can also be set individually with
           --stat-width=<width>, --stat-name-width=<name-width> and
           --stat-count=<count>.

       --compact-summary
           Output a condensed summary of extended header information such as
           file creations or deletions ("new" or "gone", optionally "+l" if
           it's a symlink) and mode changes ("+x" or "-x" for adding or
           removing executable bit respectively) in diffstat. The information
           is put between the filename part and the graph part. Implies
           --stat.

       --numstat
           Similar to --stat, but shows number of added and deleted lines in
           decimal notation and pathname without abbreviation, to make it more
           machine friendly. For binary files, outputs two - instead of saying
           0 0.

       --shortstat
           Output only the last line of the --stat format containing total
           number of modified files, as well as number of added and deleted
           lines.

       -X[<param1,param2,...>], --dirstat[=<param1,param2,...>]
           Output the distribution of relative amount of changes for each
           sub-directory. The behavior of --dirstat can be customized by
           passing it a comma separated list of parameters. The defaults are
           controlled by the diff.dirstat configuration variable (see git-
           config(1)). The following parameters are available:

           changes
               Compute the dirstat numbers by counting the lines that have
               been removed from the source, or added to the destination. This
               ignores the amount of pure code movements within a file. In
               other words, rearranging lines in a file is not counted as much
               as other changes. This is the default behavior when no
               parameter is given.

           lines
               Compute the dirstat numbers by doing the regular line-based
               diff analysis, and summing the removed/added line counts. (For
               binary files, count 64-byte chunks instead, since binary files
               have no natural concept of lines). This is a more expensive
               --dirstat behavior than the changes behavior, but it does count
               rearranged lines within a file as much as other changes. The
               resulting output is consistent with what you get from the other
               --*stat options.

           files
               Compute the dirstat numbers by counting the number of files
               changed. Each changed file counts equally in the dirstat
               analysis. This is the computationally cheapest --dirstat
               behavior, since it does not have to look at the file contents
               at all.

           cumulative
               Count changes in a child directory for the parent directory as
               well. Note that when using cumulative, the sum of the
               percentages reported may exceed 100%. The default
               (non-cumulative) behavior can be specified with the
               noncumulative parameter.

           <limit>
               An integer parameter specifies a cut-off percent (3% by
               default). Directories contributing less than this percentage of
               the changes are not shown in the output.

           Example: The following will count changed files, while ignoring
           directories with less than 10% of the total amount of changed
           files, and accumulating child directory counts in the parent
           directories: --dirstat=files,10,cumulative.

       --cumulative
           Synonym for --dirstat=cumulative

       --dirstat-by-file[=<param1,param2>...]
           Synonym for --dirstat=files,<param1>,<param2>...

       --summary
           Output a condensed summary of extended header information such as
           creations, renames and mode changes.

       --no-renames
           Turn off rename detection, even when the configuration file gives
           the default to do so.

       --[no-]rename-empty
           Whether to use empty blobs as rename source.

       --full-index
           Instead of the first handful of characters, show the full pre- and
           post-image blob object names on the "index" line when generating
           patch format output.

       --binary
           In addition to --full-index, output a binary diff that can be
           applied with git-apply.

       --abbrev[=<n>]
           Instead of showing the full 40-byte hexadecimal object name in
           diff-raw format output and diff-tree header lines, show the
           shortest prefix that is at least <n> hexdigits long that uniquely
           refers the object. In diff-patch output format, --full-index takes
           higher precedence, i.e. if --full-index is specified, full blob
           names will be shown regardless of --abbrev. Non default number of
           digits can be specified with --abbrev=<n>.

       -B[<n>][/<m>], --break-rewrites[=[<n>][/<m>]]
           Break complete rewrite changes into pairs of delete and create.
           This serves two purposes:

           It affects the way a change that amounts to a total rewrite of a
           file not as a series of deletion and insertion mixed together with
           a very few lines that happen to match textually as the context, but
           as a single deletion of everything old followed by a single
           insertion of everything new, and the number m controls this aspect
           of the -B option (defaults to 60%).  -B/70% specifies that less
           than 30% of the original should remain in the result for Git to
           consider it a total rewrite (i.e. otherwise the resulting patch
           will be a series of deletion and insertion mixed together with
           context lines).

           When used with -M, a totally-rewritten file is also considered as
           the source of a rename (usually -M only considers a file that
           disappeared as the source of a rename), and the number n controls
           this aspect of the -B option (defaults to 50%).  -B20% specifies
           that a change with addition and deletion compared to 20% or more of
           the file's size are eligible for being picked up as a possible
           source of a rename to another file.

       -M[<n>], --find-renames[=<n>]
           Detect renames. If n is specified, it is a threshold on the
           similarity index (i.e. amount of addition/deletions compared to the
           file's size). For example, -M90% means Git should consider a
           delete/add pair to be a rename if more than 90% of the file hasn't
           changed. Without a % sign, the number is to be read as a fraction,
           with a decimal point before it. I.e., -M5 becomes 0.5, and is thus
           the same as -M50%. Similarly, -M05 is the same as -M5%. To limit
           detection to exact renames, use -M100%. The default similarity
           index is 50%.

       -C[<n>], --find-copies[=<n>]
           Detect copies as well as renames. See also --find-copies-harder. If
           n is specified, it has the same meaning as for -M<n>.

       --find-copies-harder
           For performance reasons, by default, -C option finds copies only if
           the original file of the copy was modified in the same changeset.
           This flag makes the command inspect unmodified files as candidates
           for the source of copy. This is a very expensive operation for
           large projects, so use it with caution. Giving more than one -C
           option has the same effect.

       -D, --irreversible-delete
           Omit the preimage for deletes, i.e. print only the header but not
           the diff between the preimage and /dev/null. The resulting patch is
           not meant to be applied with patch or git apply; this is solely for
           people who want to just concentrate on reviewing the text after the
           change. In addition, the output obviously lacks enough information
           to apply such a patch in reverse, even manually, hence the name of
           the option.

           When used together with -B, omit also the preimage in the deletion
           part of a delete/create pair.

       -l<num>
           The -M and -C options involve some preliminary steps that can
           detect subsets of renames/copies cheaply, followed by an exhaustive
           fallback portion that compares all remaining unpaired destinations
           to all relevant sources. (For renames, only remaining unpaired
           sources are relevant; for copies, all original sources are
           relevant.) For N sources and destinations, this exhaustive check is
           O(N^2). This option prevents the exhaustive portion of rename/copy
           detection from running if the number of source/destination files
           involved exceeds the specified number. Defaults to
           diff.renameLimit. Note that a value of 0 is treated as unlimited.

       -O<orderfile>
           Control the order in which files appear in the output. This
           overrides the diff.orderFile configuration variable (see git-
           config(1)). To cancel diff.orderFile, use -O/dev/null.

           The output order is determined by the order of glob patterns in
           <orderfile>. All files with pathnames that match the first pattern
           are output first, all files with pathnames that match the second
           pattern (but not the first) are output next, and so on. All files
           with pathnames that do not match any pattern are output last, as if
           there was an implicit match-all pattern at the end of the file. If
           multiple pathnames have the same rank (they match the same pattern
           but no earlier patterns), their output order relative to each other
           is the normal order.

           <orderfile> is parsed as follows:

           o   Blank lines are ignored, so they can be used as separators for
               readability.

           o   Lines starting with a hash ("#") are ignored, so they can be
               used for comments. Add a backslash ("\") to the beginning of
               the pattern if it starts with a hash.

           o   Each other line contains a single pattern.

           Patterns have the same syntax and semantics as patterns used for
           fnmatch(3) without the FNM_PATHNAME flag, except a pathname also
           matches a pattern if removing any number of the final pathname
           components matches the pattern. For example, the pattern "foo*bar"
           matches "fooasdfbar" and "foo/bar/baz/asdf" but not "foobarx".

       --skip-to=<file>, --rotate-to=<file>
           Discard the files before the named <file> from the output (i.e.
           skip to), or move them to the end of the output (i.e.  rotate to).
           These options were invented primarily for the use of the git
           difftool command, and may not be very useful otherwise.

       --relative[=<path>], --no-relative
           When run from a subdirectory of the project, it can be told to
           exclude changes outside the directory and show pathnames relative
           to it with this option. When you are not in a subdirectory (e.g. in
           a bare repository), you can name which subdirectory to make the
           output relative to by giving a <path> as an argument.
           --no-relative can be used to countermand both diff.relative config
           option and previous --relative.

       -a, --text
           Treat all files as text.

       --ignore-cr-at-eol
           Ignore carriage-return at the end of line when doing a comparison.

       --ignore-space-at-eol
           Ignore changes in whitespace at EOL.

       -b, --ignore-space-change
           Ignore changes in amount of whitespace. This ignores whitespace at
           line end, and considers all other sequences of one or more
           whitespace characters to be equivalent.

       -w, --ignore-all-space
           Ignore whitespace when comparing lines. This ignores differences
           even if one line has whitespace where the other line has none.

       --ignore-blank-lines
           Ignore changes whose lines are all blank.

       -I<regex>, --ignore-matching-lines=<regex>
           Ignore changes whose all lines match <regex>. This option may be
           specified more than once.

       --inter-hunk-context=<lines>
           Show the context between diff hunks, up to the specified number of
           lines, thereby fusing hunks that are close to each other. Defaults
           to diff.interHunkContext or 0 if the config option is unset.

       -W, --function-context
           Show whole function as context lines for each change. The function
           names are determined in the same way as git diff works out patch
           hunk headers (see Defining a custom hunk-header in
           gitattributes(5)).

       --ext-diff
           Allow an external diff helper to be executed. If you set an
           external diff driver with gitattributes(5), you need to use this
           option with git-log(1) and friends.

       --no-ext-diff
           Disallow external diff drivers.

       --textconv, --no-textconv
           Allow (or disallow) external text conversion filters to be run when
           comparing binary files. See gitattributes(5) for details. Because
           textconv filters are typically a one-way conversion, the resulting
           diff is suitable for human consumption, but cannot be applied. For
           this reason, textconv filters are enabled by default only for git-
           diff(1) and git-log(1), but not for git-format-patch(1) or diff
           plumbing commands.

       --ignore-submodules[=<when>]
           Ignore changes to submodules in the diff generation. <when> can be
           either "none", "untracked", "dirty" or "all", which is the default.
           Using "none" will consider the submodule modified when it either
           contains untracked or modified files or its HEAD differs from the
           commit recorded in the superproject and can be used to override any
           settings of the ignore option in git-config(1) or gitmodules(5).
           When "untracked" is used submodules are not considered dirty when
           they only contain untracked content (but they are still scanned for
           modified content). Using "dirty" ignores all changes to the work
           tree of submodules, only changes to the commits stored in the
           superproject are shown (this was the behavior until 1.7.0). Using
           "all" hides all changes to submodules.

       --src-prefix=<prefix>
           Show the given source prefix instead of "a/".

       --dst-prefix=<prefix>
           Show the given destination prefix instead of "b/".

       --no-prefix
           Do not show any source or destination prefix.

       --default-prefix
           Use the default source and destination prefixes ("a/" and "b/").
           This is usually the default already, but may be used to override
           config such as diff.noprefix.

       --line-prefix=<prefix>
           Prepend an additional prefix to every line of output.

       --ita-invisible-in-index
           By default entries added by "git add -N" appear as an existing
           empty file in "git diff" and a new file in "git diff --cached".
           This option makes the entry appear as a new file in "git diff" and
           non-existent in "git diff --cached". This option could be reverted
           with --ita-visible-in-index. Both options are experimental and
           could be removed in future.

       For more detailed explanation on these common options, see also
       gitdiffcore(7).

       -<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 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.  --thread without an argument is equivalent to
           --thread=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.

       --description-file=<file>
           Use the contents of <file> instead of the branch's description for
           generating the cover letter.

       --subject-prefix=<subject-prefix>
           Instead of the standard [PATCH] prefix in the subject line, instead
           use [<subject-prefix>]. This can be used to name a patch series,
           and can be combined with the --numbered option.

           The configuration variable format.subjectPrefix may also be used to
           configure a subject prefix to apply to a given repository for all
           patches. This is often useful on mailing lists which receive
           patches for several repositories and can be used to disambiguate
           the patches (with a value of e.g. "PATCH my-project").

       --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
           Prepends "RFC" to the subject prefix (producing "RFC PATCH" by
           default). 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 iteration 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 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 git-range-
           diff(1)) for details.

       --notes[=<ref>], --no-notes
           Append the notes (see 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 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 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-Konig 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:

       o   Empty context lines that do not have any whitespace.

       o   Non-empty context lines that have one extra whitespace at the
           beginning.

       One way to test if your MUA is set up correctly is:

       o   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.

       o   Save that patch to a file in UNIX mailbox format. Call it a.patch,
           say.

       o   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.

       o   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 git-rebase(1) before regenerating it in this case.

       o   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.

       o   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 git-send-email(1).

       For hints on submission using the IMAP interface, see the EXAMPLE
       section of 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
           https://mjg.github.io/AboutConfig/ and External Editor from
           https://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
       o   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


       o   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.

       o   Extract all commits that lead to origin since the inception of the
           project:

               $ git format-patch --root origin


       o   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.

       o   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
       git-am(1), git-send-email(1)

GIT
       Part of the git(1) suite

Git 2.44.0                        02/23/2024               GIT-FORMAT-PATCH(1)