To clarify I know about
magit-revision i.e. spacebar but there doesn't seem to be a clear way to tell if a commit has more than one line of comments or not.
What I'm talking about is this:
be93ed0 master origin/master Changed the code for foo.
But then if you press spacebar you can see more of the message:
be93ed0 master origin/master Changed the code for foo. Changed it from bar to foo because of such and such.
Ideally I would like to hit "tab" and the message would expand, but I'm willing to settle for something that just indicates there is more then one line of comments.