View source for Git

For your convenience, a git mirror of the VLC svn tree has been set up. Here is a tutorial on how to use the git VLC repository.

You can read more about the VLC svn tree on our [[Subversion| Subversion wiki page]].

= Basic Git usage =
== Getting VLC source code via Git ==
 $ git clone git://git.videolan.org/vlc.git
Voilà! The full VLC history should be on your hard disk in vlc/. Type
 $ git log
to see the full log of the trunk.
 $ gitk
to see the log graphically.

You can also browse the sources via [http://git.videolan.org/cgi-bin/gitweb.cgi gitweb].


== Configure your local git repository ==
Tell git your name. (use mostly by git-commit)
 $ git repo-config user.name "Your Name"
 $ git repo-config user.email "me@example.com"


== List the local branch ==
You can now list your local branch by doing
 $ git branch
which should ouput
 $ git branch
 * master

== List your local non committed changes ==
 $ git status | less

== Commit ==
Now you can start to work on your tree. As soon as you feel you've reached a step in developement you can commit '''locally''' your work by
 $ git commit -a
or
 $ git commit <specific files>


== List your commits ==
 $ git log


== Keeping your local working branch in sync ==
 $ git fetch origin
 $ git rebase origin
voilà! Your commit will be re-applied on top of the origin (the svn trunk).


== Submitting patches to the vlc-devel ==
If you have been developing on vlc locally and (still) don't have write access, you can submit all your commit in one shot using:
 $ git format-patch -o out origin
which will produce the patches for each local commit in the directory "out".
You can also use the [http://www.kernel.org/pub/software/scm/git/docs/git-imap-send.html git-imap-send] command:
 $ git format-patch --stdout --attach -n origin | git-imap-send
which will directly produces the emails and store them in a imap mail box, provided that you have properly set up [http://www.kernel.org/pub/software/scm/git/docs/git-imap-send.html git-imap-send].


= Advanced usage =
== Creating a secondary local branch ==
If you want to work on a specific project that could require a branch of the trunk, create a local branch of the current branch by doing:
 $ git branch mywork
and to actually use it do:
 $ git checkout mywork
Which could be summarized by:
 $ git checkout -b mywork

Then do some commit on it... And you can go back to your original master branch by doing:
 $ git checkout master

== Revert your non-committed local changes ==
 $ git checkout -f

==Undo commit ==
This will undo the last commit
 $ git reset HEAD^
which is the same as
 $ git reset master^
(if you are checked-out copy of your tree is master)
And also the same as
 $ git reset a44a594 # note that there is no need to use the full sha id
if you have:
 $ git log
 commit ff7004b70fd239e4120deb160e2991bd5237b8df
 Author: fkuehne <fkuehne>
 Date:   Thu Apr 12 18:44:47 2007 +0000
     * added sanity flags for future darwin releases and potentionally fixed OSX 
 commit a44a594898f981a145cfcace5f16f8973f9eb46f
 Author: jb <jb>
 Date:   Thu Apr 12 16:24:49 2007 +0000
     Qt4 - MouseWheel support - patch by Sergey Volk.

== Diff-ing ==
* You can diff between two branches using
 $ git diff branch1 branch2
* You can diff between the previous 10th commit and current using
 $ git diff HEAD~10 HEAD
* You can diff between the previous 10th commit and current of the branch "mywork" using
 $ git diff mywork~10 mywork
* Imagine that git log is like
 $ git log
 commit e0394f269305edd09843257e7c1d1a66aaf48ab3
 Author: jb <jb>
 Date:   Fri Apr 13 07:14:48 2007 +0000
    qt4 - Mousewheel (2)
 commit e80b339081aa6755f67c9bd8e2aacf93a9a79d95
 [..]
 commit ff7004b70fd239e4120deb160e2991bd5237b8df
 [..]
 commit a44a594898f981a145cfcace5f16f8973f9eb46f
 [..]
 commit 690df705c963cf6bf6f5746d54bc97a85ff91919
 [..]
 commit 679f8b1c3e0baa469efa970588b95a625c595d64
 [..]

 $ git diff a44a594898f981a145cfcace5f16f8973f9eb46f~2 e80b339081aa6755f67c9bd8e2aacf93a9a79d95
Will be equivalent to:
 $ git diff ff7004b70fd239e4120deb160e2991bd5237b8df e80b339081aa6755f67c9bd8e2aacf93a9a79d95
And to:
 $ git diff HEAD~4 HEAD^

* Remember that to produce a patch you should rather use git-format-patch than git-diff most of the time.

== Tracking regression ==
git has a great tool called [http://www.kernel.org/pub/software/scm/git/docs/git-bisect.html git-bisect] to help you to track a faulty commit. Imagine you are tracking a bug that is known to appear after 0.8.6 (assuming 0.8.6 is tagged):
 $ git bisect start
 $ git bisect bad # tell git current version has the bug you are tracking
 $ git bisect good 0.8.6 # tell git 0.8.6 didn't has the bug
And then git will checkout a certain revision, and ask you to test it. And you simply say whether this version has the bug.
If it has the bug:
 $ git bisect bad
if the bug is not present:
 $ git bisect good
And so on by bisection... At the end git will indicate the faulty commit. Most of the time this tool is really efficient to track regression.

If you can provide a script that test the presence of the bug 
 $ git bisect run <script_name>
will be able to track down the regression by itself. See [http://www.kernel.org/pub/software/scm/git/docs/git-bisect.html git-bisect Documentation].

= Using Git (and git-svn) to commit on VideoLAN svn trunk =
== Initial checkout ==
First get the official VLC svn trunk within git
 $ git-svn init svn://your_committer_login@svn.videolan.org/svn
If you want the full history skip this step:
 $ git-svn fetch -r19800
Now get the get the rest
 $ git-svn fetch
Compress the tree:
 $ git repack -d

== Keeping in sync ==
 $ git-svn fetch
 $ git rebase

== Commit to VLC svn through git-svn ==
Once you've locally committed your changes you should be able to commit them to the remote svn branch by doing:
 $ git-svn dcommit

Note that with git-svn, you'll lost some of the git advantages, and it will probably introduce some overhead in some cases.

= Using Git to publish your work (for SoC student?) =
First get the official VLC '''Soc''' trunk
 $ git clone git://git.videolan.org/vlc-soc.git
 $ cd vlc-soc
Ask for write access to a branch (called your_name_branch). Now we will make git know that you want to publish on this branch
 $ git config remote.my_soc_public_branch.url ssh://videolan@altair.videolan.org/home/videolan/gitroot/vlc-soc.git
Now tell git that you want to automatically push the local master branch to the public your_name_branch:
 $ git config remote.my_soc_public_branch.push +master:your_name_branch # the "+" will tell git to force update ignoring conflicts

Do some work and commit it to your master branch.
 $ git commit -a
You can also sync with the trunk (origin) as needed
 $ git fetch origin
 $ git rebase origin
And don't forget to publish your changes:
 $ git push my_soc_public_branch
Now you should be able to see your latest changes in your branch via [http://git.videolan.org/cgi-bin/gitweb.cgi gitweb].

= Documentation about git =
* [http://git.or.cz/ Official Git Website]
* [http://www.kernel.org/pub/software/scm/git/docs/tutorial.html Git Tutorial]
* [http://git.or.cz/course/svn.html Switching from SVN to git using cogito]

[[Category:Building]]