Have you made some changes you'd like to submit to Trac? Great! We love to see them. To make things go smoothly for everyone, here are some guidelines on submitting your changes.
What is a patch?
A patch is a single file listing the changes you've made in a format that can be applied with the GNU patch tool. It will look something like this:
Index: /branches/0.9-stable/trac/scripts/admin.py =================================================================== --- /branches/0.9-stable/trac/scripts/admin.py (revision 2822) +++ /branches/0.9-stable/trac/scripts/admin.py (revision 3521) @@ -12,9 +12,10 @@ # history and logs, available at http://projects.edgewall.com/trac/. # +from __future__ import generators + __copyright__ = 'Copyright (c) 2003-2006 Edgewall Software' -from __future__ import generators import cmd import getpass import os
This format is called an "unified diff format". See below how to generate it.
First you will need to get a copy of the Trac source to make and test your changes. Use Subversion to get the source so that you can easily generate your patch.
Bug fixes for a current release may be added on the "stable" branch:
$ svn checkout https://svn.edgewall.org/repos/trac/branches/1.2-stable trac-1.2-stable
Features should be added on the "trunk" development version:
$ svn checkout https://svn.edgewall.org/repos/trac/trunk trac-trunk
If you're familiar with version control systems like Git or Mercurial, all the better, you should rather pick one of the official mirrors (see TracRepositories#OfficialMirrors) and develop your patches using these tools. The advantage over Subversion is that you can "document" your patches by directly adding a commit log message to them and the tool will help you maintain your patches while Trac continues to evolve upstream.
Then see how to setup a development environment.
Make some changes
Go ahead and make your changes to the Trac code.
It is a good idea to apply the CodingStyle of the Trac project to your changes, so that we won't ask you to rework your changes later on.
Test the changes using tracd.
Ideally, you should write some tests (UnitTests or FunctionalTests) demonstrating the problem you're trying to address - the tests should fail before the fix and pass with your changes. Also, by running the tests, you will see if you didn't break anything else with your changes.
A sentence like "Added some more tests - all tests pass" in your commit message is guaranteed to earn you points from the maintainers!
Did you create any new files? If you only modified existing Trac files you can skip this. However, if you added any new files be sure to tell Subversion you're adding them:
$ svn add trac/my_new_file.py
The same applies if you use Mercurial, and in Git you'll also have to "add" modified files to the index.
Make the patch
Save your changes to the file "my_patch_file.diff":
$ svn diff > my_patch_file.diff
Pick an appropriate filename for the changes you've made.
svn diff will generate a diff in the unified format. If you are using the
diff tool to produce the patch, then please use
diff -u, otherwise the diff won't be an unified diff.
With Mercurial or Git, make a commit with a detailed log message, the one you'd like to see later on in Trac itself! Then export it.
With Mercurial, assuming your patch corresponds to the latest commit:
$ hg export tip > my_patch_file.diff
With Git, assuming your patch corresponds to the head:
$ git show > my_patch_file.diff
Submit the patch
If there is an existing ticket related to the changes you've made, attach your patch file to that ticket. Otherwise please create a new ticket and attach your patch file. Provide a brief comment explaining your changes.
Add the keyword patch as a hint to developers that a patch has been provided.
After that, depending on lots of factors, your patch will be reviewed and eventually integrated. Most likely, you'll be asked to rework your patch a bit, according to the preferences of the Trac maintainers.
What is a good patch?
Now, having written a patch is no guarantee that the change will actually make it into the repository. The patch has to be endorsed by a Trac developer, who will carry the burden to maintain that change over time. So the patch has to feature the following:
- no spurious changes like whitespace change or other random reformattings
- no unrelated changes; if some refactoring really needs to be done prior to the actual change, better do that in a separate patch
- strict adherence to the CodingStyle
- code quality: the pertinence of the fix or the feature is the main criterion
That can be hard to get right the first time, so you'll certainly get asked to improve your patch. You should be willing to take feedback into account and maybe do a few iterations of the patch.