git-mailsplit, which splits mbox patches, will read the patch from stdin
when the filename is "-" or there are no files listed on the
command-line.
To be consistent with this behavior, teach the StGit patch parser to
read from stdin if the filename is "-" or no files are listed on the
command-line.
Based-on-patch-by: Chris Packham <judge.packham@gmail.com> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Paul Tan <pyokagan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>