Difference between revisions of "Submitting Patches"

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  [PATCH v2] ntdll: This patch was wrong the first time
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  [PATCH v3] comctl32: This patch has failed twice
  [PATCH v3] comctl32: This patch has failed twice
Note: if you are submitting a patch series then apply the same resubmit "version" code to the entire series (v2, v3, etc.) or it will confuse the [[Wine TestBot]], resulting in the automated tests not being run for all the patches in the series.
=== Quality check ===
=== Quality check ===

Revision as of 10:57, 20 July 2020

Translations of this page: not yet ported. Translators, please see the Discussion page.

WineHQ patch submission guidelines

In order to review code better and use established lines of communication, the Wine project accepts code in the form of patch files (instead of pushing directly to the main Git repository). The process may seem a little complicated at first, but it will probably become very natural after just one or two submissions.

Can I submit patches?

Not everyone can contribute code to Wine, primarily because doing so would violate the Clean Room Guidelines. If you have studied the Microsoft Windows source code, even if you aren't under a non-disclosure agreement, your patches probably won't be accepted. This is to ensure that the Wine project does not violate any copyrights belonging to Microsoft. Some more notes related to this can be found in the Developer FAQ.

Check your Git setup

It is important to make sure the author and email settings for your Git repo are configured correctly.

git config --global user.name "Your Name"
git config --global user.email "[email protected]"

The Git Wine Tutorial has more details, but the key point is to use your real name. This isn't just for developers to show a stronger commitment and establish trust, but also helps discourage irresponsible programmers from submitting unacceptable code (such as dissassembled Microsoft components).

Finally, there's always a chance that someone has recently changed the same code you are working on. To make sure your code hasn't been superseded, be sure to update your Git repo before generating your patch files.

git pull --rebase

If you prefer to manage your work in separate Git branches, remember that the above command will only update your current branch and all of your branches need to be up-to-date. Keeping your "master" branch in sync with WineHQ's repository and creating branches (and rebasing them on "master") for your own changes might be a good idea. Again, the Git Wine Tutorial page goes into much more detail on using Git to manage your work.

Making your changes

Code guidelines

See also Wine Developer's Guide/Coding Practice#Some notes about style

If you are making changes to the Wine program itself, there are some basic rules your code should follow to pass review:

  • When changing existing code, try to follow the style of the old code but keep in mind the rules for new code
  • Copy and pasting old code is considered adding new code!
  • When adding new code:
    • Use spaces instead of tabs
    • Use underscores instead of camelCase, except if the Windows API requires it
    • Avoid type names that start with LP (e.g. write DWORD * instead of LPDWORD)
    • Don't use Hungarian notation (e.g. write char *important_buffer instead of char *pImportantBuffer)
  • Where possible, use only portable, C89-compliant code
  • Use a consistent style in your own changes (e.g. don't write int* foo in one place and int *foo in another)
  • Limit type casts as much as possible (e.g. don't cast a VOID * to a DWORD *)
  • Remove trailing whitespace from your changes, but don't change whitespace in other lines
  • Avoid very long lines (there is no hard limit, the preferred length is 100, but 120 or 80 chars are fine too)

As a general rule, only the simplest code possible is accepted into Wine. Spend some time looking over your changes and think about whether there is a more concise or straightforward way to do what you want.

Patch guidelines

In order to make your patches as easy to check as possible, try to keep them small, clear, and atomic:

  • Only include closely related changes in one patch
  • If you've written a fix and a lot of new conformance tests for an issue, send the tests as a separate patch before the fix
  • Limit a patch to changing a single file or component unless that would break something somewhere else

These rules also make it easier to find regressions, and help prevent new bugs from slipping through.

You can also look at the patch status page to see the patches that have been submitted and committed recently. Try to imitate the style of the successful patches.

Related parts of the Wine project, such as the website, may have slightly looser requirements on patches, but it is still important to keep patches clear and simple, bundle related changes together, and not break anything.

Testing for problems

Be sure to run the conformance tests on an unchanged branch of Wine (or before you make any changes) to see where your system is OK. Then run the tests again after you make your changes to verify that they don't break anything new. If you've added or modified any of the conformance tests, be sure to check that they work properly by using the make crosstest command, then submitting the resulting executable to the Wine Test Bot.

Also, make note of any significant compiler warnings that come up when building your modified version of Wine and fix the underlying cause before submitting your patch.

The commit message

In the first line of the commit message, write the name of the component you changed, followed by a colon, one sentence in the imperative mood that will appear in the release notes, and a period. Be brief: the first line should ideally not be more than 72 characters in length.

After the first line, you may add explanatory paragraphs that tell what the patch accomplishes. Describe your changes in the imperative mood, as if you are giving orders to the codebase to change its behavior, e.g. Make xyzzy do frotz. instead of This patch makes xyzzy do frotz. or Changed xyzzy to do frotz. 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. Describe how the patch works and why it is needed, but do not repeat what the diff already shows. Wrap all paragraph lines to 72 characters.

If your patch is related to a bug, it's recommended to include a Wine-Bug line with a URL to Bugzilla (see the example below). Do not include the bug number in the first line.

Your patch must include a Signed-off-by line. Signed-off-by means "I think this code is good enough to go into Wine." It is an assertion that your work meets all legal and technical requirements of Wine development. git commit -s will add this line automatically for you.

Finally, include any extra information that you do not want included in the commit log beneath three dashes (---). If you are submitting a revised version of a patch that you submitted previously, this is where to describe the changes you made since the last version and address any feedback from other developers.

A complete example:

gdiplus: Avoid calling GdipFillPath() with an empty path.

There is no point filling an empty path, and an empty
path will cause SelectClipPath() used in brush_fill_path()
to return an error.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=987654
Signed-off-by: Zhiyi Zhang <[email protected]>
v2: Fix test breakage.

Generating and submitting patches

Creating patch files

The Git Wine Tutorial includes more details about the different ways to create patch files. In general you want:

git format-patch origin

A coding system is used in the subject line in order to sort submissions:

  • The subject line should begin with [PATCH] (in brackets)
  • If you are sending multiple patches that depend on each other, there should be a fraction inside the brackets, giving the patch's order and the total number of patches in the set (see also -n option of git format-patch):
[PATCH 1/3] This is the first patch
[PATCH 2/3] This patch depends on the first one
[PATCH 3/3] This patch depends on the others
  • Next, if you are submitting a patch for something other than Wine itself (such as the website or documentation), use --subject-prefix="PATCH <project>" to include the project code in the brackets:
[PATCH website] Add ... translation
[PATCH bugzilla] Fix ...
[PATCH docs] Update ...
[PATCH appdb] Add feature ...
[PATCH tools] Fix ...
[PATCH fontforge] Fix ...
  • Finally, if your submission somehow fell through the cracks and you're trying to send a patch again without changes, use --subject-prefix="PATCH resend". If the patch had errors and you've changed it before resubmitting, include which try you're on with -v2, -v3, etc.:
[PATCH resend] user32: This patch just got lost somehow
[PATCH website resend] This patch for the website got lost somehow
[PATCH v2] ntdll: This patch was wrong the first time
[PATCH v3] comctl32: This patch has failed twice

Note: if you are submitting a patch series then apply the same resubmit "version" code to the entire series (v2, v3, etc.) or it will confuse the Wine TestBot, resulting in the automated tests not being run for all the patches in the series.

Quality check

It never hurts to check through your patches one last time:

  • Look at each line of the patch, make sure there are no unintentional or unrelated changes
  • Remember not to actually edit the patch file itself. If you find errors, change the code and generate a new patch file.
  • Did your fix pass all related tests? If it wasn't covered by a test, have you written a test of your own?

Sending the patch

The Git Wine Tutorial includes more details about the different ways to send patch files. In general you want:

git send-email *.patch

There are a few things to look out for when mailing in your patch. First, be sure you address the patch to the wine-devel mailing list, [email protected], and remember that you need to be subscribed to the mailing list in order for your submission to get past the spam filter. If you have a long series, it is recommended to send no more than four or five patches at a time. This makes it easier for others to review your series, and makes resending your series if needed less cumbersome.

The git send-email command is strongly recommended, but if you can't get it to work, you may send the patch file as an attachment. Remember to only attach one patch per email and use the subject line from the patch file as the subject line in the email. Also, always send your emails as plain text, not HTML or rich text.

If you want to use other email clients to send patches inline, check out Email clients info for Linux for how they should be set up so that they don't mess with your patches.

Managing your submission

After you've submitted you're patch, you should watch the wine-devel mailing list for feedback on your patch (although replies should normally be cc'd to you, sometimes people may forget). If your patch does get some feedback or a critique, carefully think about what they say and fix your patch before resubmitting. If others point out a few flaws in your patch, it's safe to assume that they missed some too so try to check the whole patch and fix other flaws before resending.

Also be sure to watch the patch status page to see how far it has gone. The maintainer usually commits twenty or so patches all at once at the end of the day. If your patch had no negative feedback, the maintainer will have a look at it as soon as he can. Patches from those who have successfully committed patches before, and who are known to test their work thoroughly, are likely to be committed quickly. Patches from new developers require more scrutiny and the maintainer will probably not get to them immediately, but this does not mean your patch has been forgotten.

If your patch disappears from https://source.winehq.org/patches/ without being committed and without feedback, improving it (perhaps by adding more tests) and resending it may help, or you can ask for suggestions on the IRC channel or the developers' mailing list mentioned above. If you have patches rejected multiple times, don't be discouraged. You might consider finding a mentor willing to pre-review your patches before you send them to wine-devel (see https://www.winehq.org/pipermail/wine-devel/2010-August/086207.html for a discussion of this)

Special situations

Submitting patches written by somebody else

Occasionally, the author of a useful patch stops working on it, and somebody else has to pick it up and continue. In this case, commit the author's original patch file to your local tree (git am) and add two additional lines to the commit message (git commit --amend):

  • A From: line with the original author's name and email address. git send-email will add this automatically if the patch file has the original author's name and email instead of your own.
  • A Signed-off-by: line to indicate that you (not the original author) assert that the patch is good enough to go into Wine.

Coauthored patches

If someone else has made a significant contribution to the patch, first try to split up the patch so that each patch has only one author. If that is impractical, explain in the commit message who you collaborated with on the patch, but don't add a Signed-off-by line for anyone but yourself.

Both reviewers and coauthors indicate approval of a patch by sending a Signed-off-by line to the wine-devel mailing list. For example:

From: Nikolay Sivov <[email protected]>
To: [email protected]
Subject: Re: gdiplus: Avoid calling GdipFillPath() with an empty path.

Signed-off-by: Nikolay Sivov <[email protected]>

Multiple outstanding patchsets

Alexandre says you should concentrate on one thing and get it in before trying others. He may ignore some of your patchsets if he feels you have too many balls in the air.