Welcome to libgit2!

We‘re making it easy to do interesting things with git, and we’d love to have your help.

Licensing

By contributing to libgit2, you agree to release your contribution under the terms of the license. For code under examples, this is governed by the CC0 Public Domain Dedication. All other code is released under the GPL v2 with linking exception.

Discussion & Chat

We hang out in the #libgit2 channel on irc.freenode.net.

Also, feel free to open an Issue to start a discussion about any concerns you have. We like to use Issues for that so there is an easily accessible permanent record of the conversation.

Reporting Bugs

First, know which version of libgit2 your problem is in and include it in your bug report. This can either be a tag (e.g. v0.17.0 ) or a commit SHA (e.g. 01be7863 ). Using git describe is a great way to tell us what version you're working with.

If you‘re not running against the latest development branch version, please compile and test against that to avoid re-reporting an issue that’s already been fixed.

It‘s incredibly helpful to be able to reproduce the problem. Please include a list of steps, a bit of code, and/or a zipped repository (if possible). Note that some of the libgit2 developers are employees of GitHub, so if your repository is private, find us on IRC and we’ll figure out a way to help you.

Pull Requests

Our work flow is a typical GitHub flow, where contributors fork the libgit2 repository, make their changes on branch, and submit a Pull Request (a.k.a. “PR”).

Life will be a lot easier for you (and us) if you follow this pattern (i.e. fork, named branch, submit PR). If you use your fork's development branch, things can get messy.

Please include a nice description of your changes with your PR; if we have to read the whole diff to figure out why you‘re contributing in the first place, you’re less likely to get feedback and have your change merged in.

If you are working on a particular area then feel free to submit a PR that highlights your work in progress (and flag in the PR title that it's not ready to merge). This will help in getting visibility for your fix, allow others to comment early on the changes and also let others know that you are currently working on something.

Porting Code From Other Open-Source Projects

libgit2 is licensed under the terms of the GPL v2 with a linking exception. Any code brought in must be compatible with those terms.

The most common case is porting code from core Git. Git is a pure GPL project, which means that in order to port code to this project, we need the explicit permission of the author. Check the git.git-authors file for authors who have already consented.

Other licenses have other requirements; check the license of the library you‘re porting code from to see what you need to do. As a general rule, MIT and BSD (3-clause) licenses are typically no problem. Apache 2.0 license typically doesn’t work due to GPL incompatibility.

If you are pulling in code from core Git, another project or code you‘ve pulled from a forum / Stack Overflow then please flag this in your PR and also make sure you’ve given proper credit to the original author in the code snippet.

Style Guide

libgit2 is written in ANSI C (a.k.a. C89) with some specific conventions for function and type naming, code formatting, and testing.

We like to keep the source code consistent and easy to read. Maintaining this takes some discipline, but it's been more than worth it. Take a look at the conventions file.

Starter Projects

So, you want to start helping out with libgit2? That‘s fantastic? We welcome contributions and we promise we’ll try to be nice.

If you want to jump in, you can look at our issues list to see if there are any unresolved issues to jump in on. Also, here is a list of some smaller project ideas that could help you become familiar with the code base and make a nice first step:

  • Convert a git_*modulename*_foreach() callback-based iteration API into a git_*modulename*_iterator object with a create/advance style of API. This helps folks writing language bindings and usually isn't too complicated.
  • Write a new examples/ program that mirrors a particular core git command. (See examples/diff.c for example.) This lets you (and us) easily exercise a particular facet of the API and measure compatability and feature parity with core git.
  • Submit a PR to clarify documentation! While we do try to document all of the APIs, your fresh eyes on the documentation will find areas that are confusing much more easily.