Work In Progress
Fixes for a bug report can appear either as patches or a bzr branches. Bzr branches are preferred over patches as it is possible comment on the branch in a merge proposal and diffs can appear in-line in the bug report.
what a branch looks like
Branches and their status related to a bug report appear beneath the bug's description.
It is possible to add a branch to a bug report by clicking on "Link a related branch" in the actions portlet.
The merge proposal is actually performed outside of the bug report - when viewing the related branch.
Click on "Propose for merging".
The target branch should be the bzr branch for the development version of the package. In the "Extra options it is possible to specify a reviewer if it is set to 'ubuntu-branches' you'll want to change it to 'ubuntu-core-dev'.
removing an erroneous branch