Last Modified: 2009-10-10

Contribute code

From SipLCS

The SipLCS git repository has a branch called mob which may be changed by anyone using the user mob without requiring any authentication. This means that the branch is effectively world-writable and you can use it to commit changes without asking anyone for permission.

1. Getting the Code

Clone the SipLCS git repository using mob as user name. The mob user doesn't require any password.

git clone -n git+ssh://mob@repo.or.cz/srv/git/siplcs.git

Every git command after the initial cloning needs to be executed in the siplcs directory.

cd siplcs

Create a new local branch mob tracking the remote mob branch.

git checkout -b mob --track origin/mob

2. Changing the files

Now you can make changes to the files locally.

Test your patch:

1. Run make and SipLCS itself and make sure you did not introduce other bugs!
2. Optionally, run git diff to see what you modified, run git checkout <filename> to revert your changes
3. If everything works fine and when you're satisfied, proceed to the next step.

3. Preparing to commit changes to the server

Step 1: Identify

To make sure that your commits have your name and email address, create the file ~/.gitconfig

[user]
name = "Your Name"
email = "your@email.address.xz"

Step 2: Commit your changes locally

First review what files you have changed.

git status

Add the files you want to commit

git add <filename> #To add one file
git add -u         #To add all the files changed locally (visible with 'git status')

Then create the commit itself. This launches a text editor to allow you to enter a commit message. Please try to describe what your patch changes exactly without being overly verbose. A useful commit message increases chances that you patch will be merged to the master branch.

git commit

With the help of a GUI

Git also allows you to commit with the help of a GUI. Among other things this has the advantage that you can also select which individual hunks you'd like to commit.

git-gui

Step 3: Merge upstream changes

If you got the code of the mob branch and before you upload your patch, somebody else committed a patch to the same branch, you should try to get and merge the updates first. Otherwise the changes already in the repository will be committed twice.

git pull              # retrieve updates from server
git merge origin/mob  # merge changes into local mob-branch

If your local changes conflict with the newest source code, it will tell you and refuse to apply the remote patch.

4. Upload changes to server

Uploading your patches:

git push

Now you are done, and the patch is visible to the world at http://repo.or.cz/w/siplcs.git?a=shortlog;h=mob

5. Inform the developers

It might be a good idea that the other developers know you just committed a patch. Please send an email to the me to inform them, describing your patch. Thanks!

Other useful GIT stuff

You can see what you modified by doing:

git status

To see the differences:

git diff <somefile> # differences within a file 
git diff # all differences in the current map of the branch

And to restore the file to its original version:

git checkout <filename> # restore a file
git checkout -f # restore everything

[Summary: forget to change two occurences of cg to git]

Documentation

• A useful 'Kernel Hackers' Guide to git' can be found at http://linux.yyz.us/git-howto.html

Valgrind

Valgrind is powerful dynamic analysis tool that can f.ex. help to find memory leaks in the code. As the code uses glib we need to configure its memory allocator to behave nicely while running under valgrind:

G_DEBUG="gc-friendly" G_SLICE="always-malloc" valgrind --leak-check=yes pidgin --debug