Kaartic Sivaraam [off-list ref] writes:
While trying to merge a branch using "git merge" if a merge
message consists only of a "Sign-off" line it doesn't fail.
To be consistent with the behaviour of "git commit" shouldn't the merge
fail?
I think that it is not by design that it doesn't fail. It's not
like we decided to allow s-o-b only merge because we found a reason
why it is a good idea to do so.
So I do not think anybody minds too deeply if somebody came up a
patch to "fix" it. It's just that nobody tried to create such a
silly merge in real life so far (I do not think you did, either--you
found this out by playing around trying to find corner cases, no?)