git-format-patch(1) — Linux manual page

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

NAME         top

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

SYNOPSIS         top

       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]
                          [--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         top

       Prepare each commit with its patch in one file per commit,
       formatted to resemble UNIX mailbox format. The output of this
       command is convenient for e-mail submission or for use with git
       am.

       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         top

       -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. The width of
           the graph part can be limited by using
           --stat-graph-width=<width> (affects all commands generating a
           stat graph) or by setting diff.statGraphWidth=<width> (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 require O(n^2) processing time where n
           is the number of potential rename/copy targets. This option
           prevents rename/copy detection from running if the number of
           rename/copy targets exceeds the specified number.

       -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:

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

           •   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.

           •   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".

       --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.

       --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. 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.

       --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.

       --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.

       --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         top

       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         top

       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-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 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         top

       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 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         top

       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 track base commit
       automatically, the base commit will be the merge base of tip
       commit of the remote-tracking branch and revision-range specified
       in cmdline. For a local branch, you need to track a remote branch
       by git branch --set-upstream-to before using this option.

EXAMPLES         top

       •   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

SEE ALSO         top

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

GIT         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control
       system) project.  Information about the project can be found at
       ⟨http://git-scm.com/⟩.  If you have a bug report for this manual
       page, see ⟨http://git-scm.com/community⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨https://github.com/git/git.git⟩ on 2020-12-18.  (At that time,
       the date of the most recent commit that was found in the
       repository was 2020-12-17.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Git 2.30.0.rc0.82.gb           12/18/2020            GIT-FORMAT-PATCH(1)

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