Which branch(es) contain certain commits? (was Re: (unknown))

Ivan Chernyavsky [off-list ref] writes:

For some time I'm wondering why there's no "--grep" option to the "git
branch" command, which would request to print only branches having
specified string/regexp in their history.

So for example:

    $ git branch -r --grep=BUG12345

should be roughly equivalent to following expression I'm using now for the same task:

    $ for r in `git rev-list --grep=BUG12345 --remotes=origin`; do git
branch -r --list --contains=$r 'origin/*'; done | sort -u

Am I missing something, is there some smarter/simpler way to do this?

I think people do things like:

    git log --all --decorate --grep=...