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Difference between revisions of "Contributing code"

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In some cases we may be willing to fulfill these requirements ourselves, but that will postpone the acceptance of the contribution until we have the resources to do so. We also require a careful code review of any new code contribution by a core team member, and may have changes to request or may make changes ourselves.
 
In some cases we may be willing to fulfill these requirements ourselves, but that will postpone the acceptance of the contribution until we have the resources to do so. We also require a careful code review of any new code contribution by a core team member, and may have changes to request or may make changes ourselves.
  +
  +
== Maintaining a github fork ==
  +
  +
If you are not yet fluent in git, the following instructions may help you with preparing a contribution using a github fork. These instructions assume that you want to keep your master branch clean (containing only commits from the krb5 master branch), and prepare your contributions on topic branches.
  +
  +
After you have forked the krb5 repository on the github web site, make a local clone with (replacing YOURNAME with your github username):
  +
  +
git clone git@github.com:/YOURNAME/krb5.git
  +
cd krb5
  +
git remote add upstream git://github.com/krb5/krb5
  +
git fetch upstream
  +
  +
Within your local clone (where you'll be doing all of your work), your public github fork is now named "origin" and the upstream krb5 repository is named "upstream". You can keep the master branch of your local clone and public fork up to date with the following commands (you'll need a clean working copy for this):
  +
  +
git fetch upstream
  +
git checkout master
  +
git merge --ff-only upstream/master
  +
git push origin master
  +
  +
The --ff-only flag will cause git merge to error out if you made any commits on the master branch by mistake.
  +
  +
Before making any changes, start a topic branch with (using "mangos" as an example name for the branch):
  +
  +
git checkout -b mangos master
  +
  +
After making changes, make sure to "git add" any new files and then run:
  +
  +
git commit -a
  +
<enter your commit message>
  +
git push origin mangos
  +
  +
If your contribution fits naturally in one commit, you should now be ready to make a pull request from your github fork to the upstream krb5 repository using the github web site. Remember to let the krb5 team know about your pull request (we don't receive notifications at this time), via email or IRC (#krbdev on freenode). If we have feedback on your pull request and you want to update your patch, you can:
  +
  +
git checkout mangos
  +
<make your changes>
  +
git commit --amend -a
  +
<edit your commit message if necessary>
  +
git push origin +mangos
  +
  +
The plus sign in the final command is necessary because you're overwriting the history of your mangos branch. This is normal for topic branches which aren't yet part of the established history of a project.
  +
  +
If there are changes on the master branch that you want to make use of (or just to merge with), you can update the master branch using the instructions above and then rebase your topic branch with:
  +
  +
git rebase master mangos
  +
git push origin +mangos
  +
  +
If your contribution naturally breaks down into multiple logical commits, then you will likely need to familiarize yourself with git's tools for editing branch history, probably by learning how to use "git rebase -i". As above, use "git push origin +mangos" to update your github fork's copy of the topic branch after you are done editing its history.
  +
  +
If you want to delete your topic branch in the local repository and github fork, you can do so with:
  +
  +
git branch -D mangos
  +
git push origin :mangos
  +
  +
(Read the second command as "into the origin repository, push <empty branchname> onto the mangos branch", which causes it to be deleted.)

Revision as of 17:41, 27 May 2012

The MIT krb5 team is willing to accept code contributions in a variety of forms, but the most preferred method is a pull request for https://github.com/krb5/krb5, followed by email to krbdev@mit.edu pointing to the pull request branch. Please follow the coding style guidelines, including the version control practices.

By default, we will commit code contributions using your name and email address in the git "author" metadata field and a committer's name and email in the git "committer" metadata field. If we make changes to the contribution when committing it, we will note that in square brackets in the commit message. If you prefer otherwise, let us know.

For larger contributions such as new features, we have some additional requirements:

  • The code must be available under a permissive license such as the 2-clause BSD license used for the project itself. We encourage, but do not require, copyright to be assigned to MIT to avoid adding to the number of licenses in our notice file. (All we need to consider copyright assigned is an unambiguous statement in email.)
  • There should be a project proposal with a description of the use case and design of the change.
  • There should be an opportunity for community feedback on the krbdev@mit.edu mailing list.
  • There must be a way to test the new functionality. Automated test cases integrated with "make check" are required unless that would be unusually difficult due to the nature of the change.
  • There should be documentation of the new functionality (under doc/rst_source in the source tree).

In some cases we may be willing to fulfill these requirements ourselves, but that will postpone the acceptance of the contribution until we have the resources to do so. We also require a careful code review of any new code contribution by a core team member, and may have changes to request or may make changes ourselves.

Maintaining a github fork

If you are not yet fluent in git, the following instructions may help you with preparing a contribution using a github fork. These instructions assume that you want to keep your master branch clean (containing only commits from the krb5 master branch), and prepare your contributions on topic branches.

After you have forked the krb5 repository on the github web site, make a local clone with (replacing YOURNAME with your github username):

   git clone git@github.com:/YOURNAME/krb5.git
   cd krb5
   git remote add upstream git://github.com/krb5/krb5
   git fetch upstream

Within your local clone (where you'll be doing all of your work), your public github fork is now named "origin" and the upstream krb5 repository is named "upstream". You can keep the master branch of your local clone and public fork up to date with the following commands (you'll need a clean working copy for this):

   git fetch upstream
   git checkout master
   git merge --ff-only upstream/master
   git push origin master

The --ff-only flag will cause git merge to error out if you made any commits on the master branch by mistake.

Before making any changes, start a topic branch with (using "mangos" as an example name for the branch):

   git checkout -b mangos master

After making changes, make sure to "git add" any new files and then run:

   git commit -a
   <enter your commit message>
   git push origin mangos

If your contribution fits naturally in one commit, you should now be ready to make a pull request from your github fork to the upstream krb5 repository using the github web site. Remember to let the krb5 team know about your pull request (we don't receive notifications at this time), via email or IRC (#krbdev on freenode). If we have feedback on your pull request and you want to update your patch, you can:

   git checkout mangos
   <make your changes>
   git commit --amend -a
   <edit your commit message if necessary>
   git push origin +mangos

The plus sign in the final command is necessary because you're overwriting the history of your mangos branch. This is normal for topic branches which aren't yet part of the established history of a project.

If there are changes on the master branch that you want to make use of (or just to merge with), you can update the master branch using the instructions above and then rebase your topic branch with:

   git rebase master mangos
   git push origin +mangos

If your contribution naturally breaks down into multiple logical commits, then you will likely need to familiarize yourself with git's tools for editing branch history, probably by learning how to use "git rebase -i". As above, use "git push origin +mangos" to update your github fork's copy of the topic branch after you are done editing its history.

If you want to delete your topic branch in the local repository and github fork, you can do so with:

   git branch -D mangos
   git push origin :mangos

(Read the second command as "into the origin repository, push <empty branchname> onto the mangos branch", which causes it to be deleted.)