SubmittingPatches: fix a typo
[git/git.git] / Documentation / SubmittingPatches
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1Checklist (and a short version for the impatient):
2
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3 Commits:
4
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5 - make commits of logical units
6 - check for unnecessary whitespace with "git diff --check"
7 before committing
8 - do not check in commented out code or unneeded files
9 - provide a meaningful commit message
10 - the first line of the commit message should be a short
11 description and should skip the full stop
12 - if you want your work included in git.git, add a
8e7425da 13 "Signed-off-by: Your Name <you@example.com>" line to the
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14 commit message (or just use the option "-s" when
15 committing) to confirm that you agree to the Developer's
16 Certificate of Origin
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17 - make sure that you have tests for the bug you are fixing
18 - make sure that the test suite passes after your commit
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19
20 Patch:
21
56333bac 22 - use "git format-patch -M" to create the patch
a7af09d2 23 - do not PGP sign your patch
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24 - do not attach your patch, but read in the mail
25 body, unless you cannot teach your mailer to
26 leave the formatting of the patch alone.
27 - be careful doing cut & paste into your mailer, not to
28 corrupt whitespaces.
29 - provide additional information (which is unsuitable for
30 the commit message) between the "---" and the diffstat
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31 - if you change, add, or remove a command line option or
32 make some other user interface change, the associated
33 documentation should be updated as well.
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34 - if your name is not writable in ASCII, make sure that
35 you send off a message in the correct encoding.
13d4e6f7 36 - send the patch to the list (git@vger.kernel.org) and the
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37 maintainer (gitster@pobox.com) if (and only if) the patch
38 is ready for inclusion. If you use git-send-email(1),
39 please test it first by sending email to yourself.
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40
41Long version:
42
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43I started reading over the SubmittingPatches document for Linux
44kernel, primarily because I wanted to have a document similar to
45it for the core GIT to make sure people understand what they are
46doing when they write "Signed-off-by" line.
47
48But the patch submission requirements are a lot more relaxed
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49here on the technical/contents front, because the core GIT is
50thousand times smaller ;-). So here is only the relevant bits.
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51
52
53(1) Make separate commits for logically separate changes.
54
55Unless your patch is really trivial, you should not be sending
56out a patch that was generated between your working tree and
57your commit head. Instead, always make a commit with complete
58commit message and generate a series of patches from your
59repository. It is a good discipline.
60
61Describe the technical detail of the change(s).
62
45d2b286 63If your description starts to get too long, that's a sign that you
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64probably need to split up your commit to finer grained pieces.
65
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66Oh, another thing. I am picky about whitespaces. Make sure your
67changes do not trigger errors with the sample pre-commit hook shipped
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68in templates/hooks--pre-commit. To help ensure this does not happen,
69run git diff --check on your changes before you commit.
31408251 70
31408251 71
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72(1a) Try to be nice to older C compilers
73
8b1d88e8 74We try to support a wide range of C compilers to compile
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75git with. That means that you should not use C99 initializers, even
76if a lot of compilers grok it.
77
78Also, variables have to be declared at the beginning of the block
79(you can check this with gcc, using the -Wdeclaration-after-statement
80option).
81
82Another thing: NULL pointers shall be written as NULL, not as 0.
83
84
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85(2) Generate your patch using git tools out of your commits.
86
87git based diff tools (git, Cogito, and StGIT included) generate
88unidiff which is the preferred format.
89
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90You do not have to be afraid to use -M option to "git diff" or
91"git format-patch", if your patch involves file renames. The
92receiving end can handle them just fine.
93
94Please make sure your patch does not include any extra files
95which do not belong in a patch submission. Make sure to review
96your patch after generating it, to ensure accuracy. Before
97sending out, please make sure it cleanly applies to the "master"
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98branch head. If you are preparing a work based on "next" branch,
99that is fine, but please mark it as such.
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100
101
102(3) Sending your patches.
103
45d2b286 104People on the git mailing list need to be able to read and
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105comment on the changes you are submitting. It is important for
106a developer to be able to "quote" your changes, using standard
107e-mail tools, so that they may comment on specific portions of
addf88e4 108your code. For this reason, all patches should be submitted
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109"inline". WARNING: Be wary of your MUAs word-wrap
110corrupting your patch. Do not cut-n-paste your patch; you can
111lose tabs that way if you are not careful.
31408251 112
45d2b286 113It is a common convention to prefix your subject line with
31408251 114[PATCH]. This lets people easily distinguish patches from other
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115e-mail discussions. Use of additional markers after PATCH and
116the closing bracket to mark the nature of the patch is also
117encouraged. E.g. [PATCH/RFC] is often used when the patch is
118not ready to be applied but it is for discussion, [PATCH v2],
119[PATCH v3] etc. are often seen when you are sending an update to
120what you have previously sent.
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121
122"git format-patch" command follows the best current practice to
123format the body of an e-mail message. At the beginning of the
124patch should come your commit message, ending with the
125Signed-off-by: lines, and a line that consists of three dashes,
126followed by the diffstat information and the patch itself. If
127you are forwarding a patch from somebody else, optionally, at
128the beginning of the e-mail message just before the commit
129message starts, you can put a "From: " line to name that person.
130
131You often want to add additional explanation about the patch,
132other than the commit message itself. Place such "cover letter"
133material between the three dash lines and the diffstat.
134
135Do not attach the patch as a MIME attachment, compressed or not.
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136Do not let your e-mail client send quoted-printable. Do not let
137your e-mail client send format=flowed which would destroy
138whitespaces in your patches. Many
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139popular e-mail applications will not always transmit a MIME
140attachment as plain text, making it impossible to comment on
141your code. A MIME attachment also takes a bit more time to
142process. This does not decrease the likelihood of your
143MIME-attached change being accepted, but it makes it more likely
144that it will be postponed.
145
146Exception: If your mailer is mangling patches then someone may ask
9847f7e0 147you to re-send them using MIME, that is OK.
31408251 148
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149Do not PGP sign your patch, at least for now. Most likely, your
150maintainer or other people on the list would not have your PGP
151key and would not bother obtaining it anyway. Your patch is not
152judged by who you are; a good patch from an unknown origin has a
153far better chance of being accepted than a patch from a known,
154respected origin that is done poorly or does incorrect things.
155
156If you really really really really want to do a PGP signed
157patch, format it as "multipart/signed", not a text/plain message
158that starts with '-----BEGIN PGP SIGNED MESSAGE-----'. That is
159not a text/plain, it's something else.
160
161Note that your maintainer does not necessarily read everything
162on the git mailing list. If your patch is for discussion first,
163send it "To:" the mailing list, and optionally "cc:" him. If it
164is trivially correct or after the list reached a consensus, send
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165it "To:" the maintainer and optionally "cc:" the list for
166inclusion.
31408251 167
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168Also note that your maintainer does not actively involve himself in
169maintaining what are in contrib/ hierarchy. When you send fixes and
170enhancements to them, do not forget to "cc: " the person who primarily
171worked on that hierarchy in contrib/.
172
31408251 173
84ab7b6f 174(4) Sign your work
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175
176To improve tracking of who did what, we've borrowed the
177"sign-off" procedure from the Linux kernel project on patches
178that are being emailed around. Although core GIT is a lot
179smaller project it is a good discipline to follow it.
180
181The sign-off is a simple line at the end of the explanation for
182the patch, which certifies that you wrote it or otherwise have
183the right to pass it on as a open-source patch. The rules are
184pretty simple: if you can certify the below:
185
186 Developer's Certificate of Origin 1.1
187
188 By making a contribution to this project, I certify that:
189
190 (a) The contribution was created in whole or in part by me and I
191 have the right to submit it under the open source license
192 indicated in the file; or
193
194 (b) The contribution is based upon previous work that, to the best
195 of my knowledge, is covered under an appropriate open source
196 license and I have the right under that license to submit that
197 work with modifications, whether created in whole or in part
198 by me, under the same open source license (unless I am
199 permitted to submit under a different license), as indicated
200 in the file; or
201
202 (c) The contribution was provided directly to me by some other
203 person who certified (a), (b) or (c) and I have not modified
204 it.
205
206 (d) I understand and agree that this project and the contribution
207 are public and that a record of the contribution (including all
208 personal information I submit with it, including my sign-off) is
209 maintained indefinitely and may be redistributed consistent with
210 this project or the open source license(s) involved.
211
212then you just add a line saying
213
214 Signed-off-by: Random J Developer <random@developer.example.org>
215
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216This line can be automatically added by git if you run the git-commit
217command with the -s option.
218
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219Notice that you can place your own Signed-off-by: line when
220forwarding somebody else's patch with the above rules for
221D-C-O. Indeed you are encouraged to do so. Do not forget to
222place an in-body "From: " line at the beginning to properly attribute
223the change to its true author (see (2) above).
224
225Some people also put extra tags at the end.
226
227"Acked-by:" says that the patch was reviewed by the person who
228is more familiar with the issues and the area the patch attempts
229to modify. "Tested-by:" says the patch was tested by the person
230and found to have the desired effect.
9740d289 231
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232------------------------------------------------
233An ideal patch flow
234
235Here is an ideal patch flow for this project the current maintainer
236suggests to the contributors:
237
238 (0) You come up with an itch. You code it up.
239
240 (1) Send it to the list and cc people who may need to know about
241 the change.
242
243 The people who may need to know are the ones whose code you
244 are butchering. These people happen to be the ones who are
245 most likely to be knowledgeable enough to help you, but
246 they have no obligation to help you (i.e. you ask for help,
247 don't demand). "git log -p -- $area_you_are_modifying" would
248 help you find out who they are.
249
250 (2) You get comments and suggestions for improvements. You may
251 even get them in a "on top of your change" patch form.
252
253 (3) Polish, refine, and re-send to the list and the people who
254 spend their time to improve your patch. Go back to step (2).
255
256 (4) The list forms consensus that the last round of your patch is
257 good. Send it to the list and cc the maintainer.
258
259 (5) A topic branch is created with the patch and is merged to 'next',
260 and cooked further and eventually graduates to 'master'.
261
262In any time between the (2)-(3) cycle, the maintainer may pick it up
263from the list and queue it to 'pu', in order to make it easier for
264people play with it without having to pick up and apply the patch to
265their trees themselves.
266
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267------------------------------------------------
268MUA specific hints
269
270Some of patches I receive or pick up from the list share common
271patterns of breakage. Please make sure your MUA is set up
272properly not to corrupt whitespaces. Here are two common ones
273I have seen:
274
275* Empty context lines that do not have _any_ whitespace.
276
277* Non empty context lines that have one extra whitespace at the
278 beginning.
279
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280One test you could do yourself if your MUA is set up correctly is:
281
282* Send the patch to yourself, exactly the way you would, except
283 To: and Cc: lines, which would not contain the list and
284 maintainer address.
285
286* Save that patch to a file in UNIX mailbox format. Call it say
287 a.patch.
288
289* Try to apply to the tip of the "master" branch from the
290 git.git public repository:
291
292 $ git fetch http://kernel.org/pub/scm/git/git.git master:test-apply
293 $ git checkout test-apply
294 $ git reset --hard
59c8e2cb 295 $ git am a.patch
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296
297If it does not apply correctly, there can be various reasons.
298
299* Your patch itself does not apply cleanly. That is _bad_ but
300 does not have much to do with your MUA. Please rebase the
301 patch appropriately.
302
59c8e2cb 303* Your MUA corrupted your patch; "am" would complain that
51ef1daa 304 the patch does not apply. Look at .git/rebase-apply/ subdirectory and
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305 see what 'patch' file contains and check for the common
306 corruption patterns mentioned above.
307
308* While you are at it, check what are in 'info' and
309 'final-commit' files as well. If what is in 'final-commit' is
310 not exactly what you would want to see in the commit log
311 message, it is very likely that your maintainer would end up
312 hand editing the log message when he applies your patch.
313 Things like "Hi, this is my first patch.\n", if you really
314 want to put in the patch e-mail, should come after the
315 three-dash line that signals the end of the commit message.
316
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317
318Pine
319----
320
321(Johannes Schindelin)
322
323I don't know how many people still use pine, but for those poor
324souls it may be good to mention that the quell-flowed-text is
325needed for recent versions.
326
327... the "no-strip-whitespace-before-send" option, too. AFAIK it
328was introduced in 4.60.
329
330(Linus Torvalds)
331
332And 4.58 needs at least this.
333
334---
335diff-tree 8326dd8350be64ac7fc805f6563a1d61ad10d32c (from e886a61f76edf5410573e92e38ce22974f9c40f1)
336Author: Linus Torvalds <torvalds@g5.osdl.org>
337Date: Mon Aug 15 17:23:51 2005 -0700
338
339 Fix pine whitespace-corruption bug
340
341 There's no excuse for unconditionally removing whitespace from
342 the pico buffers on close.
343
344diff --git a/pico/pico.c b/pico/pico.c
345--- a/pico/pico.c
346+++ b/pico/pico.c
347@@ -219,7 +219,9 @@ PICO *pm;
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348 switch(pico_all_done){ /* prepare for/handle final events */
349 case COMP_EXIT : /* already confirmed */
350 packheader();
9740d289 351+#if 0
a6080a0a 352 stripwhitespace();
9740d289 353+#endif
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354 c |= COMP_EXIT;
355 break;
356
9740d289 357
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358(Daniel Barkalow)
359
360> A patch to SubmittingPatches, MUA specific help section for
361> users of Pine 4.63 would be very much appreciated.
362
363Ah, it looks like a recent version changed the default behavior to do the
364right thing, and inverted the sense of the configuration option. (Either
365that or Gentoo did it.) So you need to set the
366"no-strip-whitespace-before-send" option, unless the option you have is
367"strip-whitespace-before-send", in which case you should avoid checking
368it.
369
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370
371Thunderbird
372-----------
373
374(A Large Angry SCM)
375
376Here are some hints on how to successfully submit patches inline using
cf6de18a 377Thunderbird.
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378
379This recipe appears to work with the current [*1*] Thunderbird from Suse.
380
381The following Thunderbird extensions are needed:
382 AboutConfig 0.5
383 http://aboutconfig.mozdev.org/
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384 External Editor 0.7.2
385 http://globs.org/articles.php?lng=en&pg=8
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386
3871) Prepare the patch as a text file using your method of choice.
388
3892) Before opening a compose window, use Edit->Account Settings to
390uncheck the "Compose messages in HTML format" setting in the
391"Composition & Addressing" panel of the account to be used to send the
392patch. [*2*]
393
3943) In the main Thunderbird window, _before_ you open the compose window
395for the patch, use Tools->about:config to set the following to the
396indicated values:
397 mailnews.send_plaintext_flowed => false
cf6de18a 398 mailnews.wraplength => 0
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399
4004) Open a compose window and click the external editor icon.
401
4025) In the external editor window, read in the patch file and exit the
403editor normally.
404
4056) Back in the compose window: Add whatever other text you wish to the
406message, complete the addressing and subject fields, and press send.
407
4087) Optionally, undo the about:config/account settings changes made in
409steps 2 & 3.
410
411
412[Footnotes]
413*1* Version 1.0 (20041207) from the MozillaThunderbird-1.0-5 rpm of Suse
4149.3 professional updates.
415
416*2* It may be possible to do this with about:config and the following
417settings but I haven't tried, yet.
418 mail.html_compose => false
419 mail.identity.default.compose_html => false
420 mail.identity.id?.compose_html => false
421
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422(Lukas Sandström)
423
424There is a script in contrib/thunderbird-patch-inline which can help
425you include patches with Thunderbird in an easy way. To use it, do the
426steps above and then use the script as the external editor.
e30b217b 427
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428Gnus
429----
430
431'|' in the *Summary* buffer can be used to pipe the current
432message to an external program, and this is a handy way to drive
433"git am". However, if the message is MIME encoded, what is
434piped into the program is the representation you see in your
435*Article* buffer after unwrapping MIME. This is often not what
436you would want for two reasons. It tends to screw up non ASCII
437characters (most notably in people's names), and also
438whitespaces (fatal in patches). Running 'C-u g' to display the
439message in raw form before using '|' to run the pipe can work
440this problem around.
441
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442
443KMail
444-----
445
446This should help you to submit patches inline using KMail.
447
4481) Prepare the patch as a text file.
449
4502) Click on New Mail.
451
4523) Go under "Options" in the Composer window and be sure that
453"Word wrap" is not set.
454
4554) Use Message -> Insert file... and insert the patch.
456
4575) Back in the compose window: add whatever other text you wish to the
458message, complete the addressing and subject fields, and press send.