2011-08-11 06:59 AEST by Glen Starrett - I'm thinking there is a enhancement here for "PROMOTION BRANCHES" specifically.
 If marked as a PROMOTION BRANCH, you can't have a delta to it that isn't
straight from the concatenation of the source (e.g. mergepoint version must
match exactly).

Could also be implemented as Arthur noted:

Note: item 3, I've also thought that maybe 'rmerge' is needed - ie: a
merge/commit that happens without a sandbox.  Without a sandbox and therefore
would never permit a change that wasn't a part of the promote.