As you all know, running "mutt -F foo.rc" will have mutt read foo.rc

As you all know, running "mutt -F foo.rc" will have mutt read foo.rc
as its config file. However, there is a bug -- if you specify a
directory (like accidentally typing "mutt -F /etc/mutt") mutt will
silently ignore the flag and leave you wondering why it isn't
working.

Emil Sit posted a patch for this in March of 2002, but it seems to
have slipped through the cracks. Here's the patch again; please
consider it for inclusion.