"bound branch is out of date" error is not accurate when bound branch is superset of revisions in master

[Adrian Wilkins]

Situation ;

 * local branch - revno:n+x
 * master branch - revno:n
 * local branch is not missing any revisions from master

Attempting a non-local commit on the bound branch provokes error :

bzr: ERROR: Bound branch BzrBranch6('file:///home/adrian/nhsdd/src/publishing/') is out of date with master branch RemoteBranch(bzr://worktop/trevor/rich/publishing/trunk/).
To commit to master branch, run update and then commit.
You can also pass --local to commit to continue working disconnected.

At this point, the opposite is true ; the master branch is out of date compared to the bound branch ; it contains no revisions that are not present in the local branch.

The suggested update will create an unnecessary merge. A push resolves this seamlessly.

Suggestions ;
 * Allow commits to implicitly push to master branch when it hasn't diverged from bound branch
 * Alternately, check for this situation and suggest push to user instead of update/merge/commit cycle.