format-patch: teach format.notes config option
[git/git.git] / Documentation / git-format-patch.txt
1 git-format-patch(1)
2 ===================
3
4 NAME
5 ----
6 git-format-patch - Prepare patches for e-mail submission
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git format-patch' [-k] [(-o|--output-directory) <dir> | --stdout]
13 [--no-thread | --thread[=<style>]]
14 [(--attach|--inline)[=<boundary>] | --no-attach]
15 [-s | --signoff]
16 [--signature=<signature> | --no-signature]
17 [--signature-file=<file>]
18 [-n | --numbered | -N | --no-numbered]
19 [--start-number <n>] [--numbered-files]
20 [--in-reply-to=Message-Id] [--suffix=.<sfx>]
21 [--ignore-if-in-upstream]
22 [--rfc] [--subject-prefix=Subject-Prefix]
23 [(--reroll-count|-v) <n>]
24 [--to=<email>] [--cc=<email>]
25 [--[no-]cover-letter] [--quiet]
26 [--no-notes | --notes[=<ref>]]
27 [--interdiff=<previous>]
28 [--range-diff=<previous> [--creation-factor=<percent>]]
29 [--progress]
30 [<common diff options>]
31 [ <since> | <revision range> ]
32
33 DESCRIPTION
34 -----------
35
36 Prepare each commit with its patch in
37 one file per commit, formatted to resemble UNIX mailbox format.
38 The output of this command is convenient for e-mail submission or
39 for use with 'git am'.
40
41 There are two ways to specify which commits to operate on.
42
43 1. A single commit, <since>, specifies that the commits leading
44 to the tip of the current branch that are not in the history
45 that leads to the <since> to be output.
46
47 2. Generic <revision range> expression (see "SPECIFYING
48 REVISIONS" section in linkgit:gitrevisions[7]) means the
49 commits in the specified range.
50
51 The first rule takes precedence in the case of a single <commit>. To
52 apply the second rule, i.e., format everything since the beginning of
53 history up until <commit>, use the `--root` option: `git format-patch
54 --root <commit>`. If you want to format only <commit> itself, you
55 can do this with `git format-patch -1 <commit>`.
56
57 By default, each output file is numbered sequentially from 1, and uses the
58 first line of the commit message (massaged for pathname safety) as
59 the filename. With the `--numbered-files` option, the output file names
60 will only be numbers, without the first line of the commit appended.
61 The names of the output files are printed to standard
62 output, unless the `--stdout` option is specified.
63
64 If `-o` is specified, output files are created in <dir>. Otherwise
65 they are created in the current working directory. The default path
66 can be set with the `format.outputDirectory` configuration option.
67 The `-o` option takes precedence over `format.outputDirectory`.
68 To store patches in the current working directory even when
69 `format.outputDirectory` points elsewhere, use `-o .`.
70
71 By default, the subject of a single patch is "[PATCH] " followed by
72 the concatenation of lines from the commit message up to the first blank
73 line (see the DISCUSSION section of linkgit:git-commit[1]).
74
75 When multiple patches are output, the subject prefix will instead be
76 "[PATCH n/m] ". To force 1/1 to be added for a single patch, use `-n`.
77 To omit patch numbers from the subject, use `-N`.
78
79 If given `--thread`, `git-format-patch` will generate `In-Reply-To` and
80 `References` headers to make the second and subsequent patch mails appear
81 as replies to the first mail; this also generates a `Message-Id` header to
82 reference.
83
84 OPTIONS
85 -------
86 :git-format-patch: 1
87 include::diff-options.txt[]
88
89 -<n>::
90 Prepare patches from the topmost <n> commits.
91
92 -o <dir>::
93 --output-directory <dir>::
94 Use <dir> to store the resulting files, instead of the
95 current working directory.
96
97 -n::
98 --numbered::
99 Name output in '[PATCH n/m]' format, even with a single patch.
100
101 -N::
102 --no-numbered::
103 Name output in '[PATCH]' format.
104
105 --start-number <n>::
106 Start numbering the patches at <n> instead of 1.
107
108 --numbered-files::
109 Output file names will be a simple number sequence
110 without the default first line of the commit appended.
111
112 -k::
113 --keep-subject::
114 Do not strip/add '[PATCH]' from the first line of the
115 commit log message.
116
117 -s::
118 --signoff::
119 Add `Signed-off-by:` line to the commit message, using
120 the committer identity of yourself.
121 See the signoff option in linkgit:git-commit[1] for more information.
122
123 --stdout::
124 Print all commits to the standard output in mbox format,
125 instead of creating a file for each one.
126
127 --attach[=<boundary>]::
128 Create multipart/mixed attachment, the first part of
129 which is the commit message and the patch itself in the
130 second part, with `Content-Disposition: attachment`.
131
132 --no-attach::
133 Disable the creation of an attachment, overriding the
134 configuration setting.
135
136 --inline[=<boundary>]::
137 Create multipart/mixed attachment, the first part of
138 which is the commit message and the patch itself in the
139 second part, with `Content-Disposition: inline`.
140
141 --thread[=<style>]::
142 --no-thread::
143 Controls addition of `In-Reply-To` and `References` headers to
144 make the second and subsequent mails appear as replies to the
145 first. Also controls generation of the `Message-Id` header to
146 reference.
147 +
148 The optional <style> argument can be either `shallow` or `deep`.
149 'shallow' threading makes every mail a reply to the head of the
150 series, where the head is chosen from the cover letter, the
151 `--in-reply-to`, and the first patch mail, in this order. 'deep'
152 threading makes every mail a reply to the previous one.
153 +
154 The default is `--no-thread`, unless the `format.thread` configuration
155 is set. If `--thread` is specified without a style, it defaults to the
156 style specified by `format.thread` if any, or else `shallow`.
157 +
158 Beware that the default for 'git send-email' is to thread emails
159 itself. If you want `git format-patch` to take care of threading, you
160 will want to ensure that threading is disabled for `git send-email`.
161
162 --in-reply-to=Message-Id::
163 Make the first mail (or all the mails with `--no-thread`) appear as a
164 reply to the given Message-Id, which avoids breaking threads to
165 provide a new patch series.
166
167 --ignore-if-in-upstream::
168 Do not include a patch that matches a commit in
169 <until>..<since>. This will examine all patches reachable
170 from <since> but not from <until> and compare them with the
171 patches being generated, and any patch that matches is
172 ignored.
173
174 --subject-prefix=<Subject-Prefix>::
175 Instead of the standard '[PATCH]' prefix in the subject
176 line, instead use '[<Subject-Prefix>]'. This
177 allows for useful naming of a patch series, and can be
178 combined with the `--numbered` option.
179
180 --rfc::
181 Alias for `--subject-prefix="RFC PATCH"`. RFC means "Request For
182 Comments"; use this when sending an experimental patch for
183 discussion rather than application.
184
185 -v <n>::
186 --reroll-count=<n>::
187 Mark the series as the <n>-th iteration of the topic. The
188 output filenames have `v<n>` prepended to them, and the
189 subject prefix ("PATCH" by default, but configurable via the
190 `--subject-prefix` option) has ` v<n>` appended to it. E.g.
191 `--reroll-count=4` may produce `v4-0001-add-makefile.patch`
192 file that has "Subject: [PATCH v4 1/20] Add makefile" in it.
193
194 --to=<email>::
195 Add a `To:` header to the email headers. This is in addition
196 to any configured headers, and may be used multiple times.
197 The negated form `--no-to` discards all `To:` headers added so
198 far (from config or command line).
199
200 --cc=<email>::
201 Add a `Cc:` header to the email headers. This is in addition
202 to any configured headers, and may be used multiple times.
203 The negated form `--no-cc` discards all `Cc:` headers added so
204 far (from config or command line).
205
206 --from::
207 --from=<ident>::
208 Use `ident` in the `From:` header of each commit email. If the
209 author ident of the commit is not textually identical to the
210 provided `ident`, place a `From:` header in the body of the
211 message with the original author. If no `ident` is given, use
212 the committer ident.
213 +
214 Note that this option is only useful if you are actually sending the
215 emails and want to identify yourself as the sender, but retain the
216 original author (and `git am` will correctly pick up the in-body
217 header). Note also that `git send-email` already handles this
218 transformation for you, and this option should not be used if you are
219 feeding the result to `git send-email`.
220
221 --add-header=<header>::
222 Add an arbitrary header to the email headers. This is in addition
223 to any configured headers, and may be used multiple times.
224 For example, `--add-header="Organization: git-foo"`.
225 The negated form `--no-add-header` discards *all* (`To:`,
226 `Cc:`, and custom) headers added so far from config or command
227 line.
228
229 --[no-]cover-letter::
230 In addition to the patches, generate a cover letter file
231 containing the branch description, shortlog and the overall diffstat. You can
232 fill in a description in the file before sending it out.
233
234 --interdiff=<previous>::
235 As a reviewer aid, insert an interdiff into the cover letter,
236 or as commentary of the lone patch of a 1-patch series, showing
237 the differences between the previous version of the patch series and
238 the series currently being formatted. `previous` is a single revision
239 naming the tip of the previous series which shares a common base with
240 the series being formatted (for example `git format-patch
241 --cover-letter --interdiff=feature/v1 -3 feature/v2`).
242
243 --range-diff=<previous>::
244 As a reviewer aid, insert a range-diff (see linkgit:git-range-diff[1])
245 into the cover letter, or as commentary of the lone patch of a
246 1-patch series, showing the differences between the previous
247 version of the patch series and the series currently being formatted.
248 `previous` can be a single revision naming the tip of the previous
249 series if it shares a common base with the series being formatted (for
250 example `git format-patch --cover-letter --range-diff=feature/v1 -3
251 feature/v2`), or a revision range if the two versions of the series are
252 disjoint (for example `git format-patch --cover-letter
253 --range-diff=feature/v1~3..feature/v1 -3 feature/v2`).
254 +
255 Note that diff options passed to the command affect how the primary
256 product of `format-patch` is generated, and they are not passed to
257 the underlying `range-diff` machinery used to generate the cover-letter
258 material (this may change in the future).
259
260 --creation-factor=<percent>::
261 Used with `--range-diff`, tweak the heuristic which matches up commits
262 between the previous and current series of patches by adjusting the
263 creation/deletion cost fudge factor. See linkgit:git-range-diff[1])
264 for details.
265
266 --notes[=<ref>]::
267 --no-notes::
268 Append the notes (see linkgit:git-notes[1]) for the commit
269 after the three-dash line.
270 +
271 The expected use case of this is to write supporting explanation for
272 the commit that does not belong to the commit log message proper,
273 and include it with the patch submission. While one can simply write
274 these explanations after `format-patch` has run but before sending,
275 keeping them as Git notes allows them to be maintained between versions
276 of the patch series (but see the discussion of the `notes.rewrite`
277 configuration options in linkgit:git-notes[1] to use this workflow).
278 +
279 The default is `--no-notes`, unless the `format.notes` configuration is
280 set.
281
282 --[no-]signature=<signature>::
283 Add a signature to each message produced. Per RFC 3676 the signature
284 is separated from the body by a line with '-- ' on it. If the
285 signature option is omitted the signature defaults to the Git version
286 number.
287
288 --signature-file=<file>::
289 Works just like --signature except the signature is read from a file.
290
291 --suffix=.<sfx>::
292 Instead of using `.patch` as the suffix for generated
293 filenames, use specified suffix. A common alternative is
294 `--suffix=.txt`. Leaving this empty will remove the `.patch`
295 suffix.
296 +
297 Note that the leading character does not have to be a dot; for example,
298 you can use `--suffix=-patch` to get `0001-description-of-my-change-patch`.
299
300 -q::
301 --quiet::
302 Do not print the names of the generated files to standard output.
303
304 --no-binary::
305 Do not output contents of changes in binary files, instead
306 display a notice that those files changed. Patches generated
307 using this option cannot be applied properly, but they are
308 still useful for code review.
309
310 --zero-commit::
311 Output an all-zero hash in each patch's From header instead
312 of the hash of the commit.
313
314 --base=<commit>::
315 Record the base tree information to identify the state the
316 patch series applies to. See the BASE TREE INFORMATION section
317 below for details.
318
319 --root::
320 Treat the revision argument as a <revision range>, even if it
321 is just a single commit (that would normally be treated as a
322 <since>). Note that root commits included in the specified
323 range are always formatted as creation patches, independently
324 of this flag.
325
326 --progress::
327 Show progress reports on stderr as patches are generated.
328
329 CONFIGURATION
330 -------------
331 You can specify extra mail header lines to be added to each message,
332 defaults for the subject prefix and file suffix, number patches when
333 outputting more than one patch, add "To" or "Cc:" headers, configure
334 attachments, and sign off patches with configuration variables.
335
336 ------------
337 [format]
338 headers = "Organization: git-foo\n"
339 subjectPrefix = CHANGE
340 suffix = .txt
341 numbered = auto
342 to = <email>
343 cc = <email>
344 attach [ = mime-boundary-string ]
345 signOff = true
346 coverletter = auto
347 ------------
348
349
350 DISCUSSION
351 ----------
352
353 The patch produced by 'git format-patch' is in UNIX mailbox format,
354 with a fixed "magic" time stamp to indicate that the file is output
355 from format-patch rather than a real mailbox, like so:
356
357 ------------
358 From 8f72bad1baf19a53459661343e21d6491c3908d3 Mon Sep 17 00:00:00 2001
359 From: Tony Luck <tony.luck@intel.com>
360 Date: Tue, 13 Jul 2010 11:42:54 -0700
361 Subject: [PATCH] =?UTF-8?q?[IA64]=20Put=20ia64=20config=20files=20on=20the=20?=
362 =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig=20diet?=
363 MIME-Version: 1.0
364 Content-Type: text/plain; charset=UTF-8
365 Content-Transfer-Encoding: 8bit
366
367 arch/arm config files were slimmed down using a python script
368 (See commit c2330e286f68f1c408b4aa6515ba49d57f05beae comment)
369
370 Do the same for ia64 so we can have sleek & trim looking
371 ...
372 ------------
373
374 Typically it will be placed in a MUA's drafts folder, edited to add
375 timely commentary that should not go in the changelog after the three
376 dashes, and then sent as a message whose body, in our example, starts
377 with "arch/arm config files were...". On the receiving end, readers
378 can save interesting patches in a UNIX mailbox and apply them with
379 linkgit:git-am[1].
380
381 When a patch is part of an ongoing discussion, the patch generated by
382 'git format-patch' can be tweaked to take advantage of the 'git am
383 --scissors' feature. After your response to the discussion comes a
384 line that consists solely of "`-- >8 --`" (scissors and perforation),
385 followed by the patch with unnecessary header fields removed:
386
387 ------------
388 ...
389 > So we should do such-and-such.
390
391 Makes sense to me. How about this patch?
392
393 -- >8 --
394 Subject: [IA64] Put ia64 config files on the Uwe Kleine-K├Ânig diet
395
396 arch/arm config files were slimmed down using a python script
397 ...
398 ------------
399
400 When sending a patch this way, most often you are sending your own
401 patch, so in addition to the "`From $SHA1 $magic_timestamp`" marker you
402 should omit `From:` and `Date:` lines from the patch file. The patch
403 title is likely to be different from the subject of the discussion the
404 patch is in response to, so it is likely that you would want to keep
405 the Subject: line, like the example above.
406
407 Checking for patch corruption
408 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
409 Many mailers if not set up properly will corrupt whitespace. Here are
410 two common types of corruption:
411
412 * Empty context lines that do not have _any_ whitespace.
413
414 * Non-empty context lines that have one extra whitespace at the
415 beginning.
416
417 One way to test if your MUA is set up correctly is:
418
419 * Send the patch to yourself, exactly the way you would, except
420 with To: and Cc: lines that do not contain the list and
421 maintainer address.
422
423 * Save that patch to a file in UNIX mailbox format. Call it a.patch,
424 say.
425
426 * Apply it:
427
428 $ git fetch <project> master:test-apply
429 $ git checkout test-apply
430 $ git reset --hard
431 $ git am a.patch
432
433 If it does not apply correctly, there can be various reasons.
434
435 * The patch itself does not apply cleanly. That is _bad_ but
436 does not have much to do with your MUA. You might want to rebase
437 the patch with linkgit:git-rebase[1] before regenerating it in
438 this case.
439
440 * The MUA corrupted your patch; "am" would complain that
441 the patch does not apply. Look in the .git/rebase-apply/ subdirectory and
442 see what 'patch' file contains and check for the common
443 corruption patterns mentioned above.
444
445 * While at it, check the 'info' and 'final-commit' files as well.
446 If what is in 'final-commit' is not exactly what you would want to
447 see in the commit log message, it is very likely that the
448 receiver would end up hand editing the log message when applying
449 your patch. Things like "Hi, this is my first patch.\n" in the
450 patch e-mail should come after the three-dash line that signals
451 the end of the commit message.
452
453 MUA-SPECIFIC HINTS
454 ------------------
455 Here are some hints on how to successfully submit patches inline using
456 various mailers.
457
458 GMail
459 ~~~~~
460 GMail does not have any way to turn off line wrapping in the web
461 interface, so it will mangle any emails that you send. You can however
462 use "git send-email" and send your patches through the GMail SMTP server, or
463 use any IMAP email client to connect to the google IMAP server and forward
464 the emails through that.
465
466 For hints on using 'git send-email' to send your patches through the
467 GMail SMTP server, see the EXAMPLE section of linkgit:git-send-email[1].
468
469 For hints on submission using the IMAP interface, see the EXAMPLE
470 section of linkgit:git-imap-send[1].
471
472 Thunderbird
473 ~~~~~~~~~~~
474 By default, Thunderbird will both wrap emails as well as flag
475 them as being 'format=flowed', both of which will make the
476 resulting email unusable by Git.
477
478 There are three different approaches: use an add-on to turn off line wraps,
479 configure Thunderbird to not mangle patches, or use
480 an external editor to keep Thunderbird from mangling the patches.
481
482 Approach #1 (add-on)
483 ^^^^^^^^^^^^^^^^^^^^
484
485 Install the Toggle Word Wrap add-on that is available from
486 https://addons.mozilla.org/thunderbird/addon/toggle-word-wrap/
487 It adds a menu entry "Enable Word Wrap" in the composer's "Options" menu
488 that you can tick off. Now you can compose the message as you otherwise do
489 (cut + paste, 'git format-patch' | 'git imap-send', etc), but you have to
490 insert line breaks manually in any text that you type.
491
492 Approach #2 (configuration)
493 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
494 Three steps:
495
496 1. Configure your mail server composition as plain text:
497 Edit...Account Settings...Composition & Addressing,
498 uncheck "Compose Messages in HTML".
499
500 2. Configure your general composition window to not wrap.
501 +
502 In Thunderbird 2:
503 Edit..Preferences..Composition, wrap plain text messages at 0
504 +
505 In Thunderbird 3:
506 Edit..Preferences..Advanced..Config Editor. Search for
507 "mail.wrap_long_lines".
508 Toggle it to make sure it is set to `false`. Also, search for
509 "mailnews.wraplength" and set the value to 0.
510
511 3. Disable the use of format=flowed:
512 Edit..Preferences..Advanced..Config Editor. Search for
513 "mailnews.send_plaintext_flowed".
514 Toggle it to make sure it is set to `false`.
515
516 After that is done, you should be able to compose email as you
517 otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
518 and the patches will not be mangled.
519
520 Approach #3 (external editor)
521 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
522
523 The following Thunderbird extensions are needed:
524 AboutConfig from http://aboutconfig.mozdev.org/ and
525 External Editor from http://globs.org/articles.php?lng=en&pg=8
526
527 1. Prepare the patch as a text file using your method of choice.
528
529 2. Before opening a compose window, use Edit->Account Settings to
530 uncheck the "Compose messages in HTML format" setting in the
531 "Composition & Addressing" panel of the account to be used to
532 send the patch.
533
534 3. In the main Thunderbird window, 'before' you open the compose
535 window for the patch, use Tools->about:config to set the
536 following to the indicated values:
537 +
538 ----------
539 mailnews.send_plaintext_flowed => false
540 mailnews.wraplength => 0
541 ----------
542
543 4. Open a compose window and click the external editor icon.
544
545 5. In the external editor window, read in the patch file and exit
546 the editor normally.
547
548 Side note: it may be possible to do step 2 with
549 about:config and the following settings but no one's tried yet.
550
551 ----------
552 mail.html_compose => false
553 mail.identity.default.compose_html => false
554 mail.identity.id?.compose_html => false
555 ----------
556
557 There is a script in contrib/thunderbird-patch-inline which can help
558 you include patches with Thunderbird in an easy way. To use it, do the
559 steps above and then use the script as the external editor.
560
561 KMail
562 ~~~~~
563 This should help you to submit patches inline using KMail.
564
565 1. Prepare the patch as a text file.
566
567 2. Click on New Mail.
568
569 3. Go under "Options" in the Composer window and be sure that
570 "Word wrap" is not set.
571
572 4. Use Message -> Insert file... and insert the patch.
573
574 5. Back in the compose window: add whatever other text you wish to the
575 message, complete the addressing and subject fields, and press send.
576
577 BASE TREE INFORMATION
578 ---------------------
579
580 The base tree information block is used for maintainers or third party
581 testers to know the exact state the patch series applies to. It consists
582 of the 'base commit', which is a well-known commit that is part of the
583 stable part of the project history everybody else works off of, and zero
584 or more 'prerequisite patches', which are well-known patches in flight
585 that is not yet part of the 'base commit' that need to be applied on top
586 of 'base commit' in topological order before the patches can be applied.
587
588 The 'base commit' is shown as "base-commit: " followed by the 40-hex of
589 the commit object name. A 'prerequisite patch' is shown as
590 "prerequisite-patch-id: " followed by the 40-hex 'patch id', which can
591 be obtained by passing the patch through the `git patch-id --stable`
592 command.
593
594 Imagine that on top of the public commit P, you applied well-known
595 patches X, Y and Z from somebody else, and then built your three-patch
596 series A, B, C, the history would be like:
597
598 ................................................
599 ---P---X---Y---Z---A---B---C
600 ................................................
601
602 With `git format-patch --base=P -3 C` (or variants thereof, e.g. with
603 `--cover-letter` or using `Z..C` instead of `-3 C` to specify the
604 range), the base tree information block is shown at the end of the
605 first message the command outputs (either the first patch, or the
606 cover letter), like this:
607
608 ------------
609 base-commit: P
610 prerequisite-patch-id: X
611 prerequisite-patch-id: Y
612 prerequisite-patch-id: Z
613 ------------
614
615 For non-linear topology, such as
616
617 ................................................
618 ---P---X---A---M---C
619 \ /
620 Y---Z---B
621 ................................................
622
623 You can also use `git format-patch --base=P -3 C` to generate patches
624 for A, B and C, and the identifiers for P, X, Y, Z are appended at the
625 end of the first message.
626
627 If set `--base=auto` in cmdline, it will track base commit automatically,
628 the base commit will be the merge base of tip commit of the remote-tracking
629 branch and revision-range specified in cmdline.
630 For a local branch, you need to track a remote branch by `git branch
631 --set-upstream-to` before using this option.
632
633 EXAMPLES
634 --------
635
636 * Extract commits between revisions R1 and R2, and apply them on top of
637 the current branch using 'git am' to cherry-pick them:
638 +
639 ------------
640 $ git format-patch -k --stdout R1..R2 | git am -3 -k
641 ------------
642
643 * Extract all commits which are in the current branch but not in the
644 origin branch:
645 +
646 ------------
647 $ git format-patch origin
648 ------------
649 +
650 For each commit a separate file is created in the current directory.
651
652 * Extract all commits that lead to 'origin' since the inception of the
653 project:
654 +
655 ------------
656 $ git format-patch --root origin
657 ------------
658
659 * The same as the previous one:
660 +
661 ------------
662 $ git format-patch -M -B origin
663 ------------
664 +
665 Additionally, it detects and handles renames and complete rewrites
666 intelligently to produce a renaming patch. A renaming patch reduces
667 the amount of text output, and generally makes it easier to review.
668 Note that non-Git "patch" programs won't understand renaming patches, so
669 use it only when you know the recipient uses Git to apply your patch.
670
671 * Extract three topmost commits from the current branch and format them
672 as e-mailable patches:
673 +
674 ------------
675 $ git format-patch -3
676 ------------
677
678 SEE ALSO
679 --------
680 linkgit:git-am[1], linkgit:git-send-email[1]
681
682 GIT
683 ---
684 Part of the linkgit:git[1] suite