[RFA] Fix bug in set substitute-patch

[Joel Brobecker]

> > 2007-01-12  Joel Brobecker  <brobecker@adacore.com>
> > 
> >         * source.c (find_and_open_source): Try rewriting the source
> >         path inside filename if dirname is NULL.
> > 
> > Tested on x86-linux, no regression.
> > OK to apply?
> 
> OK, and thanks.

Thanks, Daniel. Now checked in.

-- 
Joel