Logging a merge at both ends

Hi,
We're trying to work out how we would track where a change in a branch
has been merged to.
The way I understand it is that when you merge changes from one branch
to another, only the receiving branch gets the log message.

So if we have an issue in our database that says fixed in branch x at
revision r, how can we find out where else that fix has been merged to?

My guess is that only the brute force method works at the moment - look
through the history of all branches to see which ones have received code
from that branch following the revision where the issue was fixed.

Is there some way that I can log to the branch that the merge is coming
from? I can't even figure out a way to do it manually. ie if there were
no changes to the branch, how can I commit a log entry simply to record
that this branch has been merged with branch y?

Chris

-- 
---------------------------------------------------------------------
Chris Jensen cjensen@edex.com.au
Educational Experience (Australia)
Postal Address: PO Box 860, Newcastle NSW 2300
Freecall:       1-800-025 270      International: +61-2-4923 8222
Fax:            (02) 4942 1991     International: +61-2-4942 1991
Visit our online Toy store! http://www.toysandmore.com.au/
---------------------------------------------------------------------