Difference between revisions of "WesnothRepository"

Revision as of 17:38, 2 July 2014

The Battle for Wesnoth code base is stored in a version control repository. Version control allows the entire development team to edit files concurrently. The version control software tracks revisions, stores a record of all edits, and prevents simultaneous editing from causing clashes. All changes are stored in the version control repository.

When a release is planned, the current set of the files in the repository is frozen, given a release number, and shipped out to the world at large. Then, as files continue to be edited by the developers, the repository code advances past that point. The repository (or "repo") version is by definition the most up-to-date version of the code.

The Wesnoth repository uses Git and lives at <https://github.com/wesnoth/wesnoth>.

Git

Git is the most widely used open-source version-control system. You can learn more about it at its website, <http://git-scm.com>.

Git replaced Subversion (SVN) as Wesnoth's version control system in March 2013. Subversion had itself previously replaced an older program, Concurrent Versioning System (CVS), in 2005. These earlier systems have left a few traces in the version history which you might encounter; some older documentation and a few files refer to them.

Browse the code

There are currently two main streams of development: the master branch (1.11.x), and the stable branch (1.10.x). Most other branches are only used for a short time to do some testing without disturbing the main development. You can use your web browser to navigate through the source code:

https://github.com/wesnoth/wesnoth

Download

To clone a copy of the repository into a directory called wesnoth,

git clone https://github.com/wesnoth/wesnoth.git wesnoth

Q: The repository is ~3GB! My internet connection is not stable enough to reliably download in one sitting. What to do?

A: http://stackoverflow.com/questions/9268378/how-do-i-clone-a-large-git-repository-on-an-unreliable-connection

Use any download manager to download the directory http://github.com/wesnoth/wesnoth.git, in one or multiple sessions
Rename the folder wesnoth.git to .git
Finally execute commands:

 git remote add remote http://github.com/wesnoth/wesnoth.git
 git reset --hard HEAD

This links the repo to the upstream repo, and builds your local copy of wesnoth from the info in the repo file.

Q: I don't want any alternate versions or repository history. How do I avoid downloading that?

A: This simply requires a more elaborate command. For example to only download

 git clone -b 1.12 --depth 1 --single-branch --no-hardlinks git://github.com/wesnoth/wesnoth.git wesnoth-1.12-single-branch-test

Sample output:

 $ git clone -b 1.12 --depth 1 --single-branch --no-hardlinks git://github.com/wesnoth/wesnoth.git wesnoth-1.12-single-branch-test
 Cloning into 'wesnoth-1.12-single-branch-test'...
 remote: Counting objects: 18725, done.
 remote: Compressing objects: 100% (17541/17541), done.
 remote: Total 18725 (delta 1571), reused 7397 (delta 1004)
 Receiving objects: 100% (18725/18725), 376.17 MiB | 171.00 KiB/s, done.
 Resolving deltas: 100% (1571/1571), done.
 Checking connectivity... done.
 Checking out files: 100% (18593/18593), done.
 
 $ du -sh
 1.1G	.

However, for development / testing it is often better to have some of the repository history so that you can quickly load other versions to pin down a bug.

Push access

For push access (the capability to push changes from your local repository) to our upstream repository on GitHub, you must have an account on GitHub, which must be registered as part of the Wesnoth group.

It may be convenient to use Secure Shell (SSH) transfer, so that you needn't enter your username and password each time you push commits, or insecurely store those credentials in an unencrypted configuration file. To do so, generate an SSH key pair with a command like (on Unix descendent operating systems like a Linux distribution or Apple OS X, at least) this:

ssh-keygen -t rsa -b 15360 -f <file> -C "<your name>'s SSH key for GitHub"

On Linux or Apple OS X, <file> would be, e.g., "~/.ssh/id-key-for-github".

Note that generating an SSH key pair can potentially take a while and be fairly CPU-intensive.

Then put the following into your SSH configuration file (on Unix descendent systems, this is "~/.ssh/config"):

Host github.com
	IdentityFile <file>

Then register the key with GitHub, by going to <https://github.com/settings/ssh>, selecting "Add SSH key", and pasting the contents of the public key file (<file>, but with a ".pub" extension) into the "Key" field.

Then, if you have not yet cloned the repository, clone it via SSH:

git clone git@github.com:wesnoth/wesnoth.git wesnoth

If you have already cloned the repository, you can set it to use SSH transfer:

git remote set-url origin git@github.com:wesnoth/wesnoth.git

Update

Do this from inside the wesnoth directory

git pull

Reviewing your changes

Before committing, it's always wise to run

git diff

and look at the output. Some kinds of mistakes that are hard to see embedded in all the code you have modified are more easily spotted in the isolated diff lines.

Generating patches

Under Git on a Unix-like operating system, you'll typically do

 git format-patch HEAD~1..HEAD

or something similar; "HEAD~1" may be replaced by a hash or symbolic reference to any earlier revision. This will produce one or more patch files, numbered and ending with the extension ".patch". See PatchSubmissionGuidelines for more on how to get these merged into the public repository.

Push to your own fork

If you have an account on GitHub, you can fork the repository and add your fork as a remote of your clone.

 git remote add fork git@github.com:YOUR_USERNAME/wesnoth.git

You can then push your branches to your fork:

git push fork branch_name

Or, if you want to push one branch in your local repository to another in the remote repository:

git push fork local_branch_name:remote_branch_name

You can then create pull requests from your branches in GitHub’s Web interface.