Please find patch attached.

Some notes about the patch:

TRT, I think, would be to change the whole cacheing to use Lisp objects etc. I couldn't persuade myself to do that.
A less right thing, but better than the patch, would be to protect the cache entry in re_match_2_internal. But that requires interface changes because re_match_2_internal currently doesn't know about cash entries. I couldn't bring myself to do that either.

Another note: Should some document mention that trailing whitespace are not allowed in the git repo? I couldn't find that anywhere.