Comment 5 for bug 596726

If Bob does 3 commits on top of Alices work, the new content is those three diffs, not the rest of Alices branch. That is a lot less to read in email than a full diff which would be created if Bob created a brand new proposal; if updating the branches in the original proposal would create the same email diff as creating a brand new proposal then its still suboptimal.

Using your bzr plugin to show the additional work Bob has done would be the ideal thing - still show a full diff in the web page, but don't /notify/ using a full diff.