godot/CONTRIBUTING.md

# How to contribute efficiently

Sections covered in this file:

* [Reporting bugs or proposing features](#reporting-bugs-or-proposing-features)
* [Contributing pull requests](#contributing-pull-requests)
* [Communicating with developers](#communicating-with-developers)

**Please read the first section before reporting a bug!**

## Reporting bugs or proposing features

The golden rule is to **always open *one* issue for *one* bug**. If you notice several bugs and want to report them, make sure to create one new issue for each of them.

Everything refered to hereafter as "bug" also applies for feature requests.

If you are reporting a new issue, you will make our life much simpler (and the fix come much sooner) by following those guidelines:

#### Search first in the existing database

Issues are often reported several times by various users. It's a good practice to **search first** in the issues database before reporting your issue. If you don't find a relevant match or if you are unsure, don't hesitate to **open a new issue**. The bugsquad will handle it from there if it's a duplicate.

#### Specify the platform 
 
Godot runs on a large variety of platforms and operating systems and devices. If you believe your issue is device/platform dependent (for example if it is related to the rendering, crashes or compilation errors), please specify:
* Operating system
* Device (including architecture, e.g. x86, x86_64, arm, etc.)
* GPU model (and driver in use if you know it)

#### Specify steps to reproduce

Many bugs can't be reproduced unless specific steps are taken. Please **specify the exact steps** that must be taken to reproduce the condition, and try to keep them as minimal as possible.

#### Provide a simple, example project

Sometimes an unexpected behavior happens in your project. In such case, understand that:

* What happens to you may not happen to other users.
* We can't take the time to look at your project, understand how it is set up and then figure out why it's failing.
 
To speed up our work, please prepare for us **a simple project** that isolates and reproduces the issue. This is always the **the best way for us to fix it**. You can attach a zip file with the minimal project directly to the bug report, by drag and dropping the file in the GitHub edition field.

## Contributing pull requests

If you want to add new engine functionalities, please make sure that:

* This functionality is desired.
* You talked to other developers on how to implement it best (on either communication channel, and maybe in a GitHub issue first before making your PR).
* Even if it does not get merged, your PR is useful for future work by another developer.

Similar rules can be applied when contributing bug fixes - it's always best to discuss the implementation in the bug report first if you are not 100% about what would be the best fix.

#### Be nice to the git history

Try to make simple PRs with that handle one specific topic. Just like for reporting issues, it's better to open 3 different PRs that each address a different issue than one big PR with three commits.

When updating your fork with upstream changes, please use ``git pull --rebase`` to avoid creating "merge commits". Those commits unnecessarily pollute the git history when coming from PRs.

Also try to make commits that bring the engine from one stable state to another stable state, i.e. if your first commit has a bug that you fixed in the second commit, try to merge them together before making your pull request (see ``git rebase -i`` and relevant help about rebasing or ammending commits on the Internet).

This git style guide has some good practices to have in mind: https://github.com/agis-/git-style-guide

#### Format your commit logs with readability in mind

The way you format your commit logs is quite important to ensure that the commit history and changelog will be easy to read and understand. A git commit log is formatted as a short title (first line) and an extended description (everything after the first line and an empty separation line).

The short title is the most important part, as it is what will appear in the `shortlog` changelog (one line per commit, so no description shown) or in the GitHub interface unless you click the "expand" button. As the name tells it, try to keep that first line relatively short (ideally <= 50 chars, though it's rare to be able to tell enough in so few characters, so you can go a bit higher) - it should describe what the commit does globally, while details would go in the description. Typically, if you can't keep the title short because you have too much stuff to mention, it means that you should probably split your changes in several commits :)

Here's an example of a well-formatted commit log (note how the extended description is also manually wrapped at 80 chars for readability):

```
Prevent French fries carbonization by fixing heat regulation

When using the French fries frying module, Godot would not regulate the heat
and thus bring the oil bath to supercritical liquid conditions, thus causing
unwanted side effects in the physics engine.

By fixing the regulation system via an added binding to the internal feature,
this commit now ensures that Godot will not go past the ebullition temperature
of cooking oil under normal atmospheric conditions.

Fixes #1789, long live the Realm!
```

*Note:* When using the GitHub online editor (or worse, the drag and drop feature), *please* edit the commit title to something meaningful. Commits named "Update my_file.cpp" will not be accepted.

## Communicating with developers

The Godot Engine community has [many communication channels](https://godotengine.org/community), some used more for user-level discussions and support, others more for development discussions.

To communicate with developers (e.g. to discuss a feature you want to implement or a bug you want to fix), the following channels can be used:
- [GitHub issues](https://github.com/godotengine/godot/issues): If there is an existing issue about a topic you want to discuss, just add a comment to it - all developers watch the repository and will get an email notification. You can also create a new issue - please keep in mind to create issues only to discuss quite specific points about the development, and not general user feedback or support requests.
- [#godotengine-devel IRC channel on Freenode](http://webchat.freenode.net/?channels=godotengine-devel): You will find most core developers there, so it's the go-to channel for direct chat about Godot Engine development. Feel free to start discussing something there to get some early feedback before writing up a detailed proposal in a GitHub issue.
- [devel@godotengine.org mailing list](https://listengine.tuxfamily.org/godotengine.org/devel/): Mailing list for Godot developers, used primarily to announce developer meetings on IRC and other important discussions that need to reach people directly in their mailbox. See the [index page](https://listengine.tuxfamily.org/godotengine.org/devel/) for subscription instructions.

Thanks!

The Godot development team