Expand documentation describing --signoff
[git/git.git] / Documentation / git-format-patch.txt
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1git-format-patch(1)
2===================
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3
4NAME
5----
7bd7f280 6git-format-patch - Prepare patches for e-mail submission
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7
8
9SYNOPSIS
10--------
353ce815 11[verse]
50710ce4 12'git format-patch' [-k] [(-o|--output-directory) <dir> | --stdout]
f693b7e9 13 [--no-thread | --thread[=<style>]]
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14 [(--attach|--inline)[=<boundary>] | --no-attach]
15 [-s | --signoff]
6622d9c7 16 [--signature=<signature> | --no-signature]
7022650f 17 [--signature-file=<file>]
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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]
7952ea66 22 [--subject-prefix=Subject-Prefix] [(--reroll-count|-v) <n>]
ae6c098f 23 [--to=<email>] [--cc=<email>]
2a4c2607 24 [--[no-]cover-letter] [--quiet] [--notes[=<ref>]]
50710ce4 25 [<common diff options>]
8a1d076e 26 [ <since> | <revision range> ]
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27
28DESCRIPTION
29-----------
2052d146 30
8a1d076e 31Prepare each commit with its patch in
2052d146 32one file per commit, formatted to resemble UNIX mailbox format.
2052d146 33The output of this command is convenient for e-mail submission or
0b444cdb 34for use with 'git am'.
35ef3a4c 35
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36There are two ways to specify which commits to operate on.
37
381. A single commit, <since>, specifies that the commits leading
39 to the tip of the current branch that are not in the history
40 that leads to the <since> to be output.
41
422. Generic <revision range> expression (see "SPECIFYING
9d83e382 43 REVISIONS" section in linkgit:gitrevisions[7]) means the
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44 commits in the specified range.
45
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46The first rule takes precedence in the case of a single <commit>. To
47apply the second rule, i.e., format everything since the beginning of
dce5ef14 48history up until <commit>, use the '\--root' option: `git format-patch
6cf378f0 49--root <commit>`. If you want to format only <commit> itself, you
dce5ef14 50can do this with `git format-patch -1 <commit>`.
8a1d076e 51
e6ff0f42 52By default, each output file is numbered sequentially from 1, and uses the
2052d146 53first line of the commit message (massaged for pathname safety) as
dce5ef14 54the filename. With the `--numbered-files` option, the output file names
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55will only be numbers, without the first line of the commit appended.
56The names of the output files are printed to standard
dce5ef14 57output, unless the `--stdout` option is specified.
66f04f38 58
dce5ef14 59If `-o` is specified, output files are created in <dir>. Otherwise
2052d146 60they are created in the current working directory.
35ef3a4c 61
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62By default, the subject of a single patch is "[PATCH] " followed by
63the concatenation of lines from the commit message up to the first blank
64line (see the DISCUSSION section of linkgit:git-commit[1]).
65
66When multiple patches are output, the subject prefix will instead be
67"[PATCH n/m] ". To force 1/1 to be added for a single patch, use `-n`.
68To omit patch numbers from the subject, use `-N`.
35ef3a4c 69
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70If given `--thread`, `git-format-patch` will generate `In-Reply-To` and
71`References` headers to make the second and subsequent patch mails appear
72as replies to the first mail; this also generates a `Message-Id` header to
cc35de84 73reference.
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74
75OPTIONS
76-------
c1a95fa6 77:git-format-patch: 1
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78include::diff-options.txt[]
79
ed5f07a6 80-<n>::
2c642ed8 81 Prepare patches from the topmost <n> commits.
ed5f07a6 82
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83-o <dir>::
84--output-directory <dir>::
35ef3a4c 85 Use <dir> to store the resulting files, instead of the
efd02016 86 current working directory.
35ef3a4c 87
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88-n::
89--numbered::
a567fdcb 90 Name output in '[PATCH n/m]' format, even with a single patch.
35ef3a4c 91
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92-N::
93--no-numbered::
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94 Name output in '[PATCH]' format.
95
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96--start-number <n>::
97 Start numbering the patches at <n> instead of 1.
98
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99--numbered-files::
100 Output file names will be a simple number sequence
101 without the default first line of the commit appended.
e6ff0f42 102
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103-k::
104--keep-subject::
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105 Do not strip/add '[PATCH]' from the first line of the
106 commit log message.
107
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108-s::
109--signoff::
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110 Add `Signed-off-by:` line to the commit message, using
111 the committer identity of yourself.
b2c150d3 112 See the signoff option in linkgit:git-commit[1] for more information.
6f855371 113
54ba6013 114--stdout::
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115 Print all commits to the standard output in mbox format,
116 instead of creating a file for each one.
7fc9d69f 117
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118--attach[=<boundary>]::
119 Create multipart/mixed attachment, the first part of
120 which is the commit message and the patch itself in the
dce5ef14 121 second part, with `Content-Disposition: attachment`.
c112f689 122
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123--no-attach::
124 Disable the creation of an attachment, overriding the
125 configuration setting.
126
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127--inline[=<boundary>]::
128 Create multipart/mixed attachment, the first part of
129 which is the commit message and the patch itself in the
dce5ef14 130 second part, with `Content-Disposition: inline`.
a15a44ef 131
30984ed2 132--thread[=<style>]::
f693b7e9 133--no-thread::
dce5ef14 134 Controls addition of `In-Reply-To` and `References` headers to
f693b7e9 135 make the second and subsequent mails appear as replies to the
dce5ef14 136 first. Also controls generation of the `Message-Id` header to
f693b7e9 137 reference.
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138+
139The optional <style> argument can be either `shallow` or `deep`.
fd1ff306 140'shallow' threading makes every mail a reply to the head of the
30984ed2 141series, where the head is chosen from the cover letter, the
6cf378f0 142`--in-reply-to`, and the first patch mail, in this order. 'deep'
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143threading makes every mail a reply to the previous one.
144+
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145The default is `--no-thread`, unless the 'format.thread' configuration
146is set. If `--thread` is specified without a style, it defaults to the
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147style specified by 'format.thread' if any, or else `shallow`.
148+
149Beware that the default for 'git send-email' is to thread emails
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150itself. If you want `git format-patch` to take care of threading, you
151will want to ensure that threading is disabled for `git send-email`.
28ffb898 152
da56645d 153--in-reply-to=Message-Id::
dce5ef14 154 Make the first mail (or all the mails with `--no-thread`) appear as a
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155 reply to the given Message-Id, which avoids breaking threads to
156 provide a new patch series.
157
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158--ignore-if-in-upstream::
159 Do not include a patch that matches a commit in
160 <until>..<since>. This will examine all patches reachable
161 from <since> but not from <until> and compare them with the
162 patches being generated, and any patch that matches is
163 ignored.
164
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165--subject-prefix=<Subject-Prefix>::
166 Instead of the standard '[PATCH]' prefix in the subject
167 line, instead use '[<Subject-Prefix>]'. This
168 allows for useful naming of a patch series, and can be
dce5ef14 169 combined with the `--numbered` option.
2d9e4a47 170
7952ea66 171-v <n>::
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172--reroll-count=<n>::
173 Mark the series as the <n>-th iteration of the topic. The
d614f075 174 output filenames have `v<n>` prepended to them, and the
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175 subject prefix ("PATCH" by default, but configurable via the
176 `--subject-prefix` option) has ` v<n>` appended to it. E.g.
177 `--reroll-count=4` may produce `v4-0001-add-makefile.patch`
178 file that has "Subject: [PATCH v4 1/20] Add makefile" in it.
179
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180--to=<email>::
181 Add a `To:` header to the email headers. This is in addition
182 to any configured headers, and may be used multiple times.
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183 The negated form `--no-to` discards all `To:` headers added so
184 far (from config or command line).
ae6c098f 185
736cc67d 186--cc=<email>::
dce5ef14 187 Add a `Cc:` header to the email headers. This is in addition
736cc67d 188 to any configured headers, and may be used multiple times.
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189 The negated form `--no-cc` discards all `Cc:` headers added so
190 far (from config or command line).
736cc67d 191
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192--from::
193--from=<ident>::
194 Use `ident` in the `From:` header of each commit email. If the
195 author ident of the commit is not textually identical to the
196 provided `ident`, place a `From:` header in the body of the
197 message with the original author. If no `ident` is given, use
198 the committer ident.
199+
200Note that this option is only useful if you are actually sending the
201emails and want to identify yourself as the sender, but retain the
202original author (and `git am` will correctly pick up the in-body
203header). Note also that `git send-email` already handles this
204transformation for you, and this option should not be used if you are
205feeding the result to `git send-email`.
206
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207--add-header=<header>::
208 Add an arbitrary header to the email headers. This is in addition
209 to any configured headers, and may be used multiple times.
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210 For example, `--add-header="Organization: git-foo"`.
211 The negated form `--no-add-header` discards *all* (`To:`,
212 `Cc:`, and custom) headers added so far from config or command
213 line.
d7d9c2d0 214
2a4c2607 215--[no-]cover-letter::
f4912391 216 In addition to the patches, generate a cover letter file
561d2b79 217 containing the branch description, shortlog and the overall diffstat. You can
f4912391 218 fill in a description in the file before sending it out.
a5a27c79 219
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220--notes[=<ref>]::
221 Append the notes (see linkgit:git-notes[1]) for the commit
222 after the three-dash line.
223+
224The expected use case of this is to write supporting explanation for
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225the commit that does not belong to the commit log message proper,
226and include it with the patch submission. While one can simply write
227these explanations after `format-patch` has run but before sending,
2de9b711 228keeping them as Git notes allows them to be maintained between versions
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229of the patch series (but see the discussion of the `notes.rewrite`
230configuration options in linkgit:git-notes[1] to use this workflow).
e422c0cf 231
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232--[no]-signature=<signature>::
233 Add a signature to each message produced. Per RFC 3676 the signature
234 is separated from the body by a line with '-- ' on it. If the
2de9b711 235 signature option is omitted the signature defaults to the Git version
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236 number.
237
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238--signature-file=<file>::
239 Works just like --signature except the signature is read from a file.
240
03eeaeae 241--suffix=.<sfx>::
917a8f89 242 Instead of using `.patch` as the suffix for generated
02783075 243 filenames, use specified suffix. A common alternative is
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244 `--suffix=.txt`. Leaving this empty will remove the `.patch`
245 suffix.
03eeaeae 246+
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247Note that the leading character does not have to be a dot; for example,
248you can use `--suffix=-patch` to get `0001-description-of-my-change-patch`.
03eeaeae 249
b7df098c 250-q::
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251--quiet::
252 Do not print the names of the generated files to standard output.
253
37c22a4b 254--no-binary::
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255 Do not output contents of changes in binary files, instead
256 display a notice that those files changed. Patches generated
257 using this option cannot be applied properly, but they are
258 still useful for code review.
37c22a4b 259
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260--root::
261 Treat the revision argument as a <revision range>, even if it
262 is just a single commit (that would normally be treated as a
263 <since>). Note that root commits included in the specified
264 range are always formatted as creation patches, independently
265 of this flag.
266
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267CONFIGURATION
268-------------
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269You can specify extra mail header lines to be added to each message,
270defaults for the subject prefix and file suffix, number patches when
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271outputting more than one patch, add "To" or "Cc:" headers, configure
272attachments, and sign off patches with configuration variables.
96ce6d26 273
917a8f89 274------------
96ce6d26 275[format]
7f9d77f2 276 headers = "Organization: git-foo\n"
da0005b8 277 subjectPrefix = CHANGE
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278 suffix = .txt
279 numbered = auto
ae6c098f 280 to = <email>
fe8928e6 281 cc = <email>
0db5260b 282 attach [ = mime-boundary-string ]
da0005b8 283 signOff = true
2a4c2607 284 coverletter = auto
917a8f89 285------------
03eeaeae 286
96ce6d26 287
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288DISCUSSION
289----------
290
291The patch produced by 'git format-patch' is in UNIX mailbox format,
292with a fixed "magic" time stamp to indicate that the file is output
293from format-patch rather than a real mailbox, like so:
294
295------------
296From 8f72bad1baf19a53459661343e21d6491c3908d3 Mon Sep 17 00:00:00 2001
297From: Tony Luck <tony.luck@intel.com>
298Date: Tue, 13 Jul 2010 11:42:54 -0700
299Subject: [PATCH] =?UTF-8?q?[IA64]=20Put=20ia64=20config=20files=20on=20the=20?=
300 =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig=20diet?=
301MIME-Version: 1.0
302Content-Type: text/plain; charset=UTF-8
303Content-Transfer-Encoding: 8bit
304
305arch/arm config files were slimmed down using a python script
306(See commit c2330e286f68f1c408b4aa6515ba49d57f05beae comment)
307
308Do the same for ia64 so we can have sleek & trim looking
309...
310------------
311
312Typically it will be placed in a MUA's drafts folder, edited to add
313timely commentary that should not go in the changelog after the three
314dashes, and then sent as a message whose body, in our example, starts
315with "arch/arm config files were...". On the receiving end, readers
316can save interesting patches in a UNIX mailbox and apply them with
317linkgit:git-am[1].
318
319When a patch is part of an ongoing discussion, the patch generated by
320'git format-patch' can be tweaked to take advantage of the 'git am
321--scissors' feature. After your response to the discussion comes a
322line that consists solely of "`-- >8 --`" (scissors and perforation),
323followed by the patch with unnecessary header fields removed:
324
325------------
326...
327> So we should do such-and-such.
328
329Makes sense to me. How about this patch?
330
331-- >8 --
332Subject: [IA64] Put ia64 config files on the Uwe Kleine-König diet
333
334arch/arm config files were slimmed down using a python script
335...
336------------
337
338When sending a patch this way, most often you are sending your own
339patch, so in addition to the "`From $SHA1 $magic_timestamp`" marker you
340should omit `From:` and `Date:` lines from the patch file. The patch
341title is likely to be different from the subject of the discussion the
342patch is in response to, so it is likely that you would want to keep
343the Subject: line, like the example above.
344
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345Checking for patch corruption
346~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
347Many mailers if not set up properly will corrupt whitespace. Here are
348two common types of corruption:
349
350* Empty context lines that do not have _any_ whitespace.
351
352* Non-empty context lines that have one extra whitespace at the
353 beginning.
354
355One way to test if your MUA is set up correctly is:
356
357* Send the patch to yourself, exactly the way you would, except
358 with To: and Cc: lines that do not contain the list and
359 maintainer address.
360
361* Save that patch to a file in UNIX mailbox format. Call it a.patch,
362 say.
363
364* Apply it:
365
366 $ git fetch <project> master:test-apply
367 $ git checkout test-apply
368 $ git reset --hard
369 $ git am a.patch
370
371If it does not apply correctly, there can be various reasons.
372
373* The patch itself does not apply cleanly. That is _bad_ but
374 does not have much to do with your MUA. You might want to rebase
375 the patch with linkgit:git-rebase[1] before regenerating it in
376 this case.
377
378* The MUA corrupted your patch; "am" would complain that
379 the patch does not apply. Look in the .git/rebase-apply/ subdirectory and
380 see what 'patch' file contains and check for the common
381 corruption patterns mentioned above.
382
383* While at it, check the 'info' and 'final-commit' files as well.
384 If what is in 'final-commit' is not exactly what you would want to
385 see in the commit log message, it is very likely that the
386 receiver would end up hand editing the log message when applying
387 your patch. Things like "Hi, this is my first patch.\n" in the
388 patch e-mail should come after the three-dash line that signals
389 the end of the commit message.
390
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391MUA-SPECIFIC HINTS
392------------------
393Here are some hints on how to successfully submit patches inline using
394various mailers.
395
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396GMail
397~~~~~
398GMail does not have any way to turn off line wrapping in the web
399interface, so it will mangle any emails that you send. You can however
400use "git send-email" and send your patches through the GMail SMTP server, or
401use any IMAP email client to connect to the google IMAP server and forward
402the emails through that.
403
404For hints on using 'git send-email' to send your patches through the
405GMail SMTP server, see the EXAMPLE section of linkgit:git-send-email[1].
406
407For hints on submission using the IMAP interface, see the EXAMPLE
408section of linkgit:git-imap-send[1].
409
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410Thunderbird
411~~~~~~~~~~~
412By default, Thunderbird will both wrap emails as well as flag
413them as being 'format=flowed', both of which will make the
2de9b711 414resulting email unusable by Git.
dc53151f 415
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416There are three different approaches: use an add-on to turn off line wraps,
417configure Thunderbird to not mangle patches, or use
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418an external editor to keep Thunderbird from mangling the patches.
419
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420Approach #1 (add-on)
421^^^^^^^^^^^^^^^^^^^^
422
423Install the Toggle Word Wrap add-on that is available from
424https://addons.mozilla.org/thunderbird/addon/toggle-word-wrap/
425It adds a menu entry "Enable Word Wrap" in the composer's "Options" menu
426that you can tick off. Now you can compose the message as you otherwise do
427(cut + paste, 'git format-patch' | 'git imap-send', etc), but you have to
428insert line breaks manually in any text that you type.
429
430Approach #2 (configuration)
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431^^^^^^^^^^^^^^^^^^^^^^^^^^^
432Three steps:
433
4341. Configure your mail server composition as plain text:
435 Edit...Account Settings...Composition & Addressing,
436 uncheck "Compose Messages in HTML".
437
4382. Configure your general composition window to not wrap.
439+
440In Thunderbird 2:
441Edit..Preferences..Composition, wrap plain text messages at 0
442+
443In Thunderbird 3:
444Edit..Preferences..Advanced..Config Editor. Search for
445"mail.wrap_long_lines".
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446Toggle it to make sure it is set to `false`. Also, search for
447"mailnews.wraplength" and set the value to 0.
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448
4493. Disable the use of format=flowed:
450Edit..Preferences..Advanced..Config Editor. Search for
451"mailnews.send_plaintext_flowed".
452Toggle it to make sure it is set to `false`.
453
454After that is done, you should be able to compose email as you
455otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
456and the patches will not be mangled.
457
b8959605 458Approach #3 (external editor)
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459^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
460
461The following Thunderbird extensions are needed:
462AboutConfig from http://aboutconfig.mozdev.org/ and
463External Editor from http://globs.org/articles.php?lng=en&pg=8
464
4651. Prepare the patch as a text file using your method of choice.
466
4672. Before opening a compose window, use Edit->Account Settings to
468 uncheck the "Compose messages in HTML format" setting in the
469 "Composition & Addressing" panel of the account to be used to
470 send the patch.
471
4723. In the main Thunderbird window, 'before' you open the compose
473 window for the patch, use Tools->about:config to set the
474 following to the indicated values:
475+
476----------
477 mailnews.send_plaintext_flowed => false
478 mailnews.wraplength => 0
479----------
480
4814. Open a compose window and click the external editor icon.
482
4835. In the external editor window, read in the patch file and exit
484 the editor normally.
485
486Side note: it may be possible to do step 2 with
487about:config and the following settings but no one's tried yet.
488
489----------
490 mail.html_compose => false
491 mail.identity.default.compose_html => false
492 mail.identity.id?.compose_html => false
493----------
494
495There is a script in contrib/thunderbird-patch-inline which can help
496you include patches with Thunderbird in an easy way. To use it, do the
497steps above and then use the script as the external editor.
498
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499KMail
500~~~~~
501This should help you to submit patches inline using KMail.
502
5031. Prepare the patch as a text file.
504
5052. Click on New Mail.
506
5073. Go under "Options" in the Composer window and be sure that
508 "Word wrap" is not set.
509
5104. Use Message -> Insert file... and insert the patch.
511
5125. Back in the compose window: add whatever other text you wish to the
513 message, complete the addressing and subject fields, and press send.
514
e0d48279 515
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516EXAMPLES
517--------
518
921177f5 519* Extract commits between revisions R1 and R2, and apply them on top of
0b444cdb 520the current branch using 'git am' to cherry-pick them:
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521+
522------------
467c0197 523$ git format-patch -k --stdout R1..R2 | git am -3 -k
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524------------
525
526* Extract all commits which are in the current branch but not in the
527origin branch:
528+
529------------
530$ git format-patch origin
531------------
532+
533For each commit a separate file is created in the current directory.
534
535* Extract all commits that lead to 'origin' since the inception of the
536project:
537+
538------------
9c67c757 539$ git format-patch --root origin
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540------------
541
542* The same as the previous one:
543+
544------------
545$ git format-patch -M -B origin
546------------
547+
548Additionally, it detects and handles renames and complete rewrites
549intelligently to produce a renaming patch. A renaming patch reduces
50710ce4 550the amount of text output, and generally makes it easier to review.
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551Note that non-Git "patch" programs won't understand renaming patches, so
552use it only when you know the recipient uses Git to apply your patch.
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553
554* Extract three topmost commits from the current branch and format them
555as e-mailable patches:
556+
557------------
558$ git format-patch -3
559------------
28ffb898 560
56ae8df5 561SEE ALSO
28ffb898 562--------
5162e697 563linkgit:git-am[1], linkgit:git-send-email[1]
28ffb898 564
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565GIT
566---
9e1f0a85 567Part of the linkgit:git[1] suite