Development:Git repository

This page provides some information about our switch to git (which we're slowly trying to make, starting with the tmwserv and server-data projects). As an initial comforting note, git really isn't so complicated as some people would have you believe. A few months ago I became familiar with distributed version control by using Mercurial, and since a few weeks we're using git at work. I think we'll benefit a lot from switching to it on the long run.

The primary repository

Initial setup

With git, everybody has his own repository. But of course we will keep a central repository through which we cooperate. This central repository is currently hosted at gitorious.org, a friendly website that is also open source. It uses ssh's private/public key authentication for identifying committers.

• TMWServ project page: http://gitorious.org/projects/tmwserv
• eAthena data project page: http://gitorious.org/projects/tmw-eathena-data

On Gitorious you can have multiple repositories for each project. The main one (and I suggest we keep just one for the moment) is called mainline. Once you click to the mainline repository, you can see several ways to clone it (the new 'svn checkout'). For development purposes you should clone the "Push url", but this requires that you have:

1. Signed up to gitorious.org
2. Generated a private/public ssh keypair (if you haven't got this already)
3. Filled in your public key in your account details on Gitorious

Cloning

If you simply git clone the URL without any additional arguments, it will create the repository in a directory called "mainline". This is generally not what you want. Hence, after the clone url, you should pass the name of the directory you want to have created (just like with Subversion):

$ git clone <clone_url> project

If you want to have all projects in one place, you probably want to do something like this:

$ mkdir tmw
$ cd tmw
$ git clone git@gitorious.org:tmwserv/mainline.git tmwserv
$ git clone git@gitorious.org:tmw-eathena-data/mainline.git eathena-data
etc.

The way Gitorious works, we can't have one top-level "tmw" project under which we put all these repositories, since they're really separate projects. Gitorious allows multiple repositories for each project, but they are clones of each other (you can only create new ones by cloning existing ones). This allows anybody (not just the development team) to make clones and start hacking on them. Changes can easily be merged from one one repository to another. So instead of all the inconvenience with TMW forks we had in the past, now comes the time to encourage people to clone!

Working with git

Commit

From now on, a commit is something you do locally. Others won't see your change on Gitorious unless you push it there. You'll notice committing is very fast, and you can commit multiple times before you decide to push. You can also make corrections to your last commit.

Before you start committing, it is important to identify yourself to git, so that it can include the correct authorship information with your commit. You are no longer identified with a username, as was the case with Subversion. You can read exactly how to do this, as well as other useful information geared towards people switching from Subversion, on this page:

• Git - SVN Crash Course: http://git.or.cz/course/svn.html

Pushing

Once you have committed some stuff, you can push these to the repository on Gitorious using git push. This works since by default the push command pushes to a remote called origin, and this remote is automatically set up when you clone. However, the push will fail if there have been new commits on the remote repository. In that case, you'll first have to pull in these changes (just like with Subversion, however Subversion allowed this as long as the same files weren't touched, git doesn't).

Pulling

When you want to get the latest changes from the repository on Gitorious, you generally use git pull. However, note that this command does not work when you have local changes. Also, when you have local commits, the pull command will generate a merge commit (and before that you may have to resolve some conflicts).

If you don't want to create merge commits, but would rather stack your local commits on top of any incoming commits, you should use git pull --rebase. This rebases your local commits on top of the incoming ones. You should never do this when you have pushed these commits elsewhere, so only do it when you are sure the commits are only on your machine.

If you have local changes and want to update your checkout, then there are several options:

• You commit your local changes, and do a pull, optionally with --rebase.
• Or you use git stash to place your local changes on a "hidden" stash. Then, after pulling, you apply your changes again with git stash apply.
• Or you create a patch of your local changes that you apply again after the pull. This approach sometimes makes sense, but I would say in general it's the more clumsy way to go. There are git commands that help you with this though.

Resolving conflicts

TODO