This brings to changes from OpenBSD:
Revision 1.57
sometimes patches coming from other places have extra a/ and b/
directories prepended to filenames. detect this condition and attempt to
correct it.
ok openbsd
Revision 1.58
Unbreak previous for git diffs that do not have the a/ prefix.
Found the hard way be me, OK tedu
Plus some minor adaption so that we still support perforce-style diffs.