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Diffstat (limited to 'Documentation/SubmittingPatches')
| -rw-r--r-- | Documentation/SubmittingPatches | 513 |
1 files changed, 275 insertions, 238 deletions
diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches index ba07c8c571..bc8ad00473 100644 --- a/Documentation/SubmittingPatches +++ b/Documentation/SubmittingPatches @@ -1,54 +1,38 @@ -Checklist (and a short version for the impatient): - - Commits: - - - make commits of logical units - - check for unnecessary whitespace with "git diff --check" - before committing - - do not check in commented out code or unneeded files - - provide a meaningful commit message - - the first line of the commit message should be a short - description and should skip the full stop - - if you want your work included in git.git, add a - "Signed-off-by: Your Name <you@example.com>" line to the - commit message (or just use the option "-s" when - committing) to confirm that you agree to the Developer's - Certificate of Origin - - make sure that you have tests for the bug you are fixing - - make sure that the test suite passes after your commit - - Patch: - - - use "git format-patch -M" to create the patch - - do not PGP sign your patch - - do not attach your patch, but read in the mail - body, unless you cannot teach your mailer to - leave the formatting of the patch alone. - - be careful doing cut & paste into your mailer, not to - corrupt whitespaces. - - provide additional information (which is unsuitable for - the commit message) between the "---" and the diffstat - - if you change, add, or remove a command line option or - make some other user interface change, the associated - documentation should be updated as well. - - if your name is not writable in ASCII, make sure that - you send off a message in the correct encoding. - - send the patch to the list (git@vger.kernel.org) and the - maintainer (gitster@pobox.com) if (and only if) the patch - is ready for inclusion. If you use git-send-email(1), - please test it first by sending email to yourself. - -Long version: - -I started reading over the SubmittingPatches document for Linux -kernel, primarily because I wanted to have a document similar to -it for the core GIT to make sure people understand what they are -doing when they write "Signed-off-by" line. - -But the patch submission requirements are a lot more relaxed -here on the technical/contents front, because the core GIT is -thousand times smaller ;-). So here is only the relevant bits. +Here are some guidelines for people who want to contribute their code +to this software. +(0) Decide what to base your work on. + +In general, always base your work on the oldest branch that your +change is relevant to. + + - A bugfix should be based on 'maint' in general. If the bug is not + present in 'maint', base it on 'master'. For a bug that's not yet + in 'master', find the topic that introduces the regression, and + base your work on the tip of the topic. + + - A new feature should be based on 'master' in general. If the new + feature depends on a topic that is in 'pu', but not in 'master', + base your work on the tip of that topic. + + - Corrections and enhancements to a topic not yet in 'master' should + be based on the tip of that topic. If the topic has not been merged + to 'next', it's alright to add a note to squash minor corrections + into the series. + + - In the exceptional case that a new feature depends on several topics + not in 'master', start working on 'next' or 'pu' privately and send + out patches for discussion. Before the final merge, you may have to + wait until some of the dependent topics graduate to 'master', and + rebase your work. + + - Some parts of the system have dedicated maintainers with their own + repositories (see the section "Subsystems" below). Changes to + these parts should be based on their trees. + +To find the tip of a topic branch, run "git log --first-parent +master..pu" and look for the merge commit. The second parent of this +commit is the tip of the topic branch. (1) Make separate commits for logically separate changes. @@ -58,55 +42,143 @@ your commit head. Instead, always make a commit with complete commit message and generate a series of patches from your repository. It is a good discipline. -Describe the technical detail of the change(s). +Give an explanation for the change(s) that is detailed enough so +that people can judge if it is good thing to do, without reading +the actual patch text to determine how well the code does what +the explanation promises to do. If your description starts to get too long, that's a sign that you probably need to split up your commit to finer grained pieces. - -Oh, another thing. I am picky about whitespaces. Make sure your +That being said, patches which plainly describe the things that +help reviewers check the patch, and future maintainers understand +the code, are the most beautiful patches. Descriptions that summarise +the point in the subject well, and describe the motivation for the +change, the approach taken by the change, and if relevant how this +differs substantially from the prior version, are all good things +to have. + +Make sure that you have tests for the bug you are fixing. See +t/README for guidance. + +When adding a new feature, make sure that you have new tests to show +the feature triggers the new behavior when it should, and to show the +feature does not trigger when it shouldn't. After any code change, make +sure that the entire test suite passes. + +If you have an account at GitHub (and you can get one for free to work +on open source projects), you can use their Travis CI integration to +test your changes on Linux, Mac (and hopefully soon Windows). See +GitHub-Travis CI hints section for details. + +Do not forget to update the documentation to describe the updated +behavior and make sure that the resulting documentation set formats +well. It is currently a liberal mixture of US and UK English norms for +spelling and grammar, which is somewhat unfortunate. A huge patch that +touches the files all over the place only to correct the inconsistency +is not welcome, though. Potential clashes with other changes that can +result from such a patch are not worth it. We prefer to gradually +reconcile the inconsistencies in favor of US English, with small and +easily digestible patches, as a side effect of doing some other real +work in the vicinity (e.g. rewriting a paragraph for clarity, while +turning en_UK spelling to en_US). Obvious typographical fixes are much +more welcomed ("teh -> "the"), preferably submitted as independent +patches separate from other documentation changes. + +Oh, another thing. We are picky about whitespaces. Make sure your changes do not trigger errors with the sample pre-commit hook shipped in templates/hooks--pre-commit. To help ensure this does not happen, run git diff --check on your changes before you commit. -(1a) Try to be nice to older C compilers +(2) Describe your changes well. + +The first line of the commit message should be a short description (50 +characters is the soft limit, see DISCUSSION in git-commit(1)), and +should skip the full stop. It is also conventional in most cases to +prefix the first line with "area: " where the area is a filename or +identifier for the general area of the code being modified, e.g. + + . doc: clarify distinction between sign-off and pgp-signing + . githooks.txt: improve the intro section -We try to support a wide range of C compilers to compile -git with. That means that you should not use C99 initializers, even -if a lot of compilers grok it. +If in doubt which identifier to use, run "git log --no-merges" on the +files you are modifying to see the current conventions. -Also, variables have to be declared at the beginning of the block -(you can check this with gcc, using the -Wdeclaration-after-statement -option). +It's customary to start the remainder of the first line after "area: " +with a lower-case letter. E.g. "doc: clarify...", not "doc: +Clarify...", or "githooks.txt: improve...", not "githooks.txt: +Improve...". -Another thing: NULL pointers shall be written as NULL, not as 0. +The body should provide a meaningful commit message, which: + . explains the problem the change tries to solve, iow, what is wrong + with the current code without the change. -(2) Generate your patch using git tools out of your commits. + . justifies the way the change solves the problem, iow, why the + result with the change is better. -git based diff tools (git, Cogito, and StGIT included) generate -unidiff which is the preferred format. + . alternate solutions considered but discarded, if any. + +Describe your changes in imperative mood, e.g. "make xyzzy do frotz" +instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy +to do frotz", as if you are giving orders to the codebase to change +its behaviour. Try to make sure your explanation can be understood +without external resources. Instead of giving a URL to a mailing list +archive, summarize the relevant points of the discussion. + +If you want to reference a previous commit in the history of a stable +branch, use the format "abbreviated sha1 (subject, date)", +with the subject enclosed in a pair of double-quotes, like this: + + Commit f86a374 ("pack-bitmap.c: fix a memleak", 2015-03-30) + noticed that ... + +The "Copy commit summary" command of gitk can be used to obtain this +format, or this invocation of "git show": + + git show -s --date=short --pretty='format:%h ("%s", %ad)' <commit> + +(3) Generate your patch using Git tools out of your commits. + +Git based diff tools generate unidiff which is the preferred format. You do not have to be afraid to use -M option to "git diff" or "git format-patch", if your patch involves file renames. The receiving end can handle them just fine. -Please make sure your patch does not include any extra files -which do not belong in a patch submission. Make sure to review +Please make sure your patch does not add commented out debugging code, +or include any extra files which do not relate to what your patch +is trying to achieve. Make sure to review your patch after generating it, to ensure accuracy. Before sending out, please make sure it cleanly applies to the "master" branch head. If you are preparing a work based on "next" branch, that is fine, but please mark it as such. -(3) Sending your patches. +(4) Sending your patches. + +Learn to use format-patch and send-email if possible. These commands +are optimized for the workflow of sending patches, avoiding many ways +your existing e-mail client that is optimized for "multipart/*" mime +type e-mails to corrupt and render your patches unusable. -People on the git mailing list need to be able to read and +People on the Git mailing list need to be able to read and comment on the changes you are submitting. It is important for a developer to be able to "quote" your changes, using standard e-mail tools, so that they may comment on specific portions of -your code. For this reason, all patches should be submitted -"inline". WARNING: Be wary of your MUAs word-wrap +your code. For this reason, each patch should be submitted +"inline" in a separate message. + +Multiple related patches should be grouped into their own e-mail +thread to help readers find all parts of the series. To that end, +send them as replies to either an additional "cover letter" message +(see below), the first patch, or the respective preceding patch. + +If your log message (including your name on the +Signed-off-by line) is not writable in ASCII, make sure that +you send off a message in the correct encoding. + +WARNING: Be wary of your MUAs word-wrap corrupting your patch. Do not cut-n-paste your patch; you can lose tabs that way if you are not careful. @@ -130,7 +202,11 @@ message starts, you can put a "From: " line to name that person. You often want to add additional explanation about the patch, other than the commit message itself. Place such "cover letter" -material between the three dash lines and the diffstat. +material between the three-dash line and the diffstat. For +patches requiring multiple iterations of review and discussion, +an explanation of changes between each iteration can be kept in +Git-notes and inserted automatically following the three-dash +line via `git format-patch --notes`. Do not attach the patch as a MIME attachment, compressed or not. Do not let your e-mail client send quoted-printable. Do not let @@ -146,36 +222,40 @@ that it will be postponed. Exception: If your mailer is mangling patches then someone may ask you to re-send them using MIME, that is OK. -Do not PGP sign your patch, at least for now. Most likely, your -maintainer or other people on the list would not have your PGP -key and would not bother obtaining it anyway. Your patch is not -judged by who you are; a good patch from an unknown origin has a -far better chance of being accepted than a patch from a known, -respected origin that is done poorly or does incorrect things. +Do not PGP sign your patch. Most likely, your maintainer or other people on the +list would not have your PGP key and would not bother obtaining it anyway. +Your patch is not judged by who you are; a good patch from an unknown origin +has a far better chance of being accepted than a patch from a known, respected +origin that is done poorly or does incorrect things. If you really really really really want to do a PGP signed patch, format it as "multipart/signed", not a text/plain message that starts with '-----BEGIN PGP SIGNED MESSAGE-----'. That is not a text/plain, it's something else. -Note that your maintainer does not necessarily read everything -on the git mailing list. If your patch is for discussion first, -send it "To:" the mailing list, and optionally "cc:" him. If it -is trivially correct or after the list reached a consensus, send -it "To:" the maintainer and optionally "cc:" the list for -inclusion. +Send your patch with "To:" set to the mailing list, with "cc:" listing +people who are involved in the area you are touching (the output from +"git blame $path" and "git shortlog --no-merges $path" would help to +identify them), to solicit comments and reviews. + +After the list reached a consensus that it is a good idea to apply the +patch, re-send it with "To:" set to the maintainer [*1*] and "cc:" the +list [*2*] for inclusion. + +Do not forget to add trailers such as "Acked-by:", "Reviewed-by:" and +"Tested-by:" lines as necessary to credit people who helped your +patch. -Also note that your maintainer does not actively involve himself in -maintaining what are in contrib/ hierarchy. When you send fixes and -enhancements to them, do not forget to "cc: " the person who primarily -worked on that hierarchy in contrib/. + [Addresses] + *1* The current maintainer: gitster@pobox.com + *2* The mailing list: git@vger.kernel.org -(4) Sign your work +(5) Certify your work by adding your "Signed-off-by: " line To improve tracking of who did what, we've borrowed the "sign-off" procedure from the Linux kernel project on patches -that are being emailed around. Although core GIT is a lot +that are being emailed around. Although core Git is a lot smaller project it is a good discipline to follow it. The sign-off is a simple line at the end of the explanation for @@ -203,17 +283,17 @@ pretty simple: if you can certify the below: person who certified (a), (b) or (c) and I have not modified it. - (d) I understand and agree that this project and the contribution - are public and that a record of the contribution (including all - personal information I submit with it, including my sign-off) is - maintained indefinitely and may be redistributed consistent with - this project or the open source license(s) involved. + (d) I understand and agree that this project and the contribution + are public and that a record of the contribution (including all + personal information I submit with it, including my sign-off) is + maintained indefinitely and may be redistributed consistent with + this project or the open source license(s) involved. then you just add a line saying - Signed-off-by: Random J Developer <random@developer.example.org> + Signed-off-by: Random J Developer <random@developer.example.org> -This line can be automatically added by git if you run the git-commit +This line can be automatically added by Git if you run the git-commit command with the -s option. Notice that you can place your own Signed-off-by: line when @@ -225,12 +305,41 @@ the change to its true author (see (2) above). Also notice that a real name is used in the Signed-off-by: line. Please don't hide your real name. -Some people also put extra tags at the end. +If you like, you can put extra tags at the end: + +1. "Reported-by:" is used to credit someone who found the bug that + the patch attempts to fix. +2. "Acked-by:" says that the person who is more familiar with the area + the patch attempts to modify liked the patch. +3. "Reviewed-by:", unlike the other tags, can only be offered by the + reviewer and means that she is completely satisfied that the patch + is ready for application. It is usually offered only after a + detailed review. +4. "Tested-by:" is used to indicate that the person applied the patch + and found it to have the desired effect. + +You can also create your own tag or use one that's in common usage +such as "Thanks-to:", "Based-on-patch-by:", or "Mentored-by:". + +------------------------------------------------ +Subsystems with dedicated maintainers + +Some parts of the system have dedicated maintainers with their own +repositories. + + - git-gui/ comes from git-gui project, maintained by Pat Thoyts: + + git://repo.or.cz/git-gui.git -"Acked-by:" says that the patch was reviewed by the person who -is more familiar with the issues and the area the patch attempts -to modify. "Tested-by:" says the patch was tested by the person -and found to have the desired effect. + - gitk-git/ comes from Paul Mackerras's gitk project: + + git://ozlabs.org/~paulus/gitk + + - po/ comes from the localization coordinator, Jiang Xin: + + https://github.com/git-l10n/git-po/ + +Patches to these parts should be based on their trees. ------------------------------------------------ An ideal patch flow @@ -257,7 +366,7 @@ suggests to the contributors: spend their time to improve your patch. Go back to step (2). (4) The list forms consensus that the last round of your patch is - good. Send it to the list and cc the maintainer. + good. Send it to the maintainer and cc the list. (5) A topic branch is created with the patch and is merged to 'next', and cooked further and eventually graduates to 'master'. @@ -268,54 +377,79 @@ people play with it without having to pick up and apply the patch to their trees themselves. ------------------------------------------------ -MUA specific hints +Know the status of your patch after submission -Some of patches I receive or pick up from the list share common -patterns of breakage. Please make sure your MUA is set up -properly not to corrupt whitespaces. Here are two common ones -I have seen: +* You can use Git itself to find out when your patch is merged in + master. 'git pull --rebase' will automatically skip already-applied + patches, and will let you know. This works only if you rebase on top + of the branch in which your patch has been merged (i.e. it will not + tell you if your patch is merged in pu if you rebase on top of + master). + +* Read the Git mailing list, the maintainer regularly posts messages + entitled "What's cooking in git.git" and "What's in git.git" giving + the status of various proposed changes. -* Empty context lines that do not have _any_ whitespace. +-------------------------------------------------- +GitHub-Travis CI hints -* Non empty context lines that have one extra whitespace at the - beginning. +With an account at GitHub (you can get one for free to work on open +source projects), you can use Travis CI to test your changes on Linux, +Mac (and hopefully soon Windows). You can find a successful example +test build here: https://travis-ci.org/git/git/builds/120473209 -One test you could do yourself if your MUA is set up correctly is: +Follow these steps for the initial setup: -* Send the patch to yourself, exactly the way you would, except - To: and Cc: lines, which would not contain the list and - maintainer address. + (1) Fork https://github.com/git/git to your GitHub account. + You can find detailed instructions how to fork here: + https://help.github.com/articles/fork-a-repo/ -* Save that patch to a file in UNIX mailbox format. Call it say - a.patch. + (2) Open the Travis CI website: https://travis-ci.org -* Try to apply to the tip of the "master" branch from the - git.git public repository: + (3) Press the "Sign in with GitHub" button. - $ git fetch http://kernel.org/pub/scm/git/git.git master:test-apply - $ git checkout test-apply - $ git reset --hard - $ git am a.patch + (4) Grant Travis CI permissions to access your GitHub account. + You can find more information about the required permissions here: + https://docs.travis-ci.com/user/github-oauth-scopes -If it does not apply correctly, there can be various reasons. + (5) Open your Travis CI profile page: https://travis-ci.org/profile -* Your patch itself does not apply cleanly. That is _bad_ but - does not have much to do with your MUA. Please rebase the - patch appropriately. + (6) Enable Travis CI builds for your Git fork. -* Your MUA corrupted your patch; "am" would complain that - the patch does not apply. Look at .git/rebase-apply/ subdirectory and - see what 'patch' file contains and check for the common - corruption patterns mentioned above. +After the initial setup, Travis CI will run whenever you push new changes +to your fork of Git on GitHub. You can monitor the test state of all your +branches here: https://travis-ci.org/<Your GitHub handle>/git/branches -* While you are at it, check what are in '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 your maintainer would end up - hand editing the log message when he applies your patch. - Things like "Hi, this is my first patch.\n", if you really - want to put in the patch e-mail, should come after the - three-dash line that signals the end of the commit message. +If a branch did not pass all test cases then it is marked with a red +cross. In that case you can click on the failing Travis CI job and +scroll all the way down in the log. Find the line "<-- Click here to see +detailed test output!" and click on the triangle next to the log line +number to expand the detailed test output. Here is such a failing +example: https://travis-ci.org/git/git/jobs/122676187 + +Fix the problem and push your fix to your Git fork. This will trigger +a new Travis CI build to ensure all tests pass. + + +------------------------------------------------ +MUA specific hints + +Some of patches I receive or pick up from the list share common +patterns of breakage. Please make sure your MUA is set up +properly not to corrupt whitespaces. + +See the DISCUSSION section of git-format-patch(1) for hints on +checking your patch by mailing it to yourself and applying with +git-am(1). + +While you are at it, check the resulting commit log message from +a trial run of applying the patch. If what is in the resulting +commit is not exactly what you would want to see, it is very +likely that your maintainer would end up hand editing the log +message when he applies your patch. Things like "Hi, this is my +first patch.\n", if you really want to put in the patch e-mail, +should come after the three-dash line that signals the end of the +commit message. Pine @@ -371,62 +505,10 @@ that or Gentoo did it.) So you need to set the it. -Thunderbird ------------ - -(A Large Angry SCM) - -Here are some hints on how to successfully submit patches inline using -Thunderbird. - -This recipe appears to work with the current [*1*] Thunderbird from Suse. - -The following Thunderbird extensions are needed: - AboutConfig 0.5 - http://aboutconfig.mozdev.org/ - External Editor 0.7.2 - 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. [*2*] - -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. - -6) Back in the compose window: Add whatever other text you wish to the -message, complete the addressing and subject fields, and press send. - -7) Optionally, undo the about:config/account settings changes made in -steps 2 & 3. - +Thunderbird, KMail, GMail +------------------------- -[Footnotes] -*1* Version 1.0 (20041207) from the MozillaThunderbird-1.0-5 rpm of Suse -9.3 professional updates. - -*2* It may be possible to do this with about:config and the following -settings but I haven't tried, yet. - mail.html_compose => false - mail.identity.default.compose_html => false - mail.identity.id?.compose_html => false - -(Lukas Sandström) - -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. +See the MUA-SPECIFIC HINTS section of git-format-patch(1). Gnus ---- @@ -441,48 +523,3 @@ characters (most notably in people's names), and also whitespaces (fatal in patches). Running 'C-u g' to display the message in raw form before using '|' to run the pipe can work this problem around. - - -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. - - -Gmail ------ - -Submitting properly formatted patches via Gmail is simple now that -IMAP support is available. First, edit your ~/.gitconfig to specify your -account settings: - -[imap] - folder = "[Gmail]/Drafts" - host = imaps://imap.gmail.com - user = user@gmail.com - pass = p4ssw0rd - port = 993 - sslverify = false - -Next, ensure that your Gmail settings are correct. In "Settings" the -"Use Unicode (UTF-8) encoding for outgoing messages" should be checked. - -Once your commits are ready to send to the mailing list, run the following -command to send the patch emails to your Gmail Drafts folder. - - $ git format-patch -M --stdout origin/master | git imap-send - -Go to your Gmail account, open the Drafts folder, find the patch email, fill -in the To: and CC: fields and send away! |