When developing code and fixes for the 0.11.x branch, it should be first checked into trunk,then merged into 0.11.x branch. Right now I'm dealing as a I merge code from trunk to the branch, I'm dealing with merge conflicts in the attachment encoding code, which should have been in trunk all along.
The only time when code shouldn't go into trunk is when it's doesn't at all apply to trunk, because the code in trunk has already diverged because of post-1.0 feature work. -Damien