#summary Useful hints for contributing code to Hedgewars

*Table of Contents*

<wiki:toc max_depth="2" />

= Introduction =

You want to contribute code to Hedgewars? That's great! Here are some hints how to help us with importing your code.

= Recommended workflows =

== Using a mercurial clone ==

TODO

=== Using (named) branches ===

Branches are alternative commit histories.

The commits history from one branch, up to any commit, can be merged into other branches when needed.

Note: In Mercurial merging a commit always means to also merge all its ancestor commits.

_Most main development happens on the main repository branch "default"._

We prefer *not* to use separate branches for little patches, as branches are permanent and will clutter the list of {{{hg branches}}}.

*So for small code contributions, use "unnamed branches" instead (see below).*

_However, if you are going to write code that is more a project than a patch and that will take dozens of commits, feel free to do that work on a new branch._

To create a new branch use {{{hg branch}}} followed by the name of the new branch, before committing the first code.

=== Using unnamed branches ===

_Unnamed branches_ a.k.a. _topological branches_ happen when the history of commits within a branch (e.g. "default") splits up into  alternative commits chains.

These alternative chains will have more than one {{{head}}} (at the the end of each chain) within the same branch, until they will be merged back together into a single chain.

*In order for us to be able which bugfixes/features of you we merge into the official repository, you should put each in a separate _unnamed branch_ as described above.*

Make sure that the first commit of each bugfix/feature commit set is based on a commit from the official repository, that way your bugfixes/features will not depend on the commits of each other and can be merged into official individually, as needed.

That means: *Before you start writing code towards a new bugfix/feature, make sure to {{{hg update}}} to a revision from the official repository.*

In newer versions of Mercurial you can give those unnamed branches a "local" and removable name using {{{hg bookmark}}}.

*You can see example of how unnamed branches and bookmarks are used best [http://hg.hedgewars.org/hw-example-clone/graph HERE]*

= How to export your changes so that we can use them  =

== Public Repository ==

If you setup a public repository e.g. at github, bitbucket or on your own server, just push your commits there.

Then send us the links to the commits/bookmarks that you want to go into the official repository!

== Export mercurial commits ==

With {{{hg export --git -r commitid1 -rcommitid2 ... > my.patch}}} you can export the commits specified to a patch file.

Note: the {{{--git}}} argument is used, so that binary file changes (e.g. changed pictures), are included in the export.

== Creating a file containing the code differences ==

You can use the {{{diff}}} command (if available on your platform) to output the differences between e.g. the original code and yours.

Save that into a file and send it to us.

Note: Don't forget to also send binary files, so pictures/etc. that you changed - since usually {{{diff}}} will only cover text changes!

If you have a mercurial clone of the official repository but you don't want to locally commit your changes for some reason, you can use use {{{hg diff --git > my.diff}}} to generate a diff file containing changes to code and binary files.

= How to ask for patch inclusion in official repository =

Just send your patches (or links to them) to [/contact.html] the development mailing list]. Feel free to compress them as {{{tar.gz}}}, {{{tar.bz2}}} or {{{zip}}}.

Don't forget to add a short description (can be a copy of the commit message if it's explaining everything needed).

That implies that your code *will be made public* under the *[http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html GNU GPL2]*.