Subversion Reminders - Branching, Merging and Rollbacks

Below are a few Subversion reminders on how to branch, merge and rollback changes.

To create a branch from the HEAD of the trunk:

svn copy http://<server>/<svn repo>/<svn project>/branches/<branch name>

You can add a -m <comment> onto the operation to provide a reason for the branch.

To delete a branch:

svn delete http://<server>/<svn repo>/<svn project>/branches/<branch name>

If for some reason you want to include changes from the trunk post-branch, then you can use the merge command from the branch root directory. A useful precursor to this is to use the dry run argument as below:

svn merge --dry-run -r2602:HEAD http://<server>/<svn repo>/<svn project>/trunk

NOTE: 2602 is non-inclusive i.e. revisions merged will start from 2603 onwards.

Now do the actual merge:

svn merge -r2602:HEAD http://<server>/<svn repo>/<svn project>/trunk

No doubt there will be conflicts so once resolved in your favourite IDE, check the changes in.

The above commands assume you noted down the revision number (2602) when branching. If not known, then from the branch root directory, execute the below command:

svn log -v --stop-on-copy

To merge branch changes into the trunk, the merge command can be used in similar fashion from the trunk root directory:

svn merge -r2602:HEAD http://<server>/<svn repo>/<svn project>/branches/<branch name>

If you want to rollback commited changes, then you can use the merge command with the -r argument:

svn merge -r10:9 http://<server>/<svn repo>/<svn project>/trunk

To rollback a commit that took place a while ago and others that have been committed since, use the merge command again:

svn merge -r7:5 http://<server>/<svn repo>/<svn project>/trunk

NOTE: Note that this will revert revisions 7 and 6. Revision 5 is the target revision that we want to keep.

Many thanks to Rob Legg of Asset Source Ltd for the above summary.