This works for "darcs show patchindex --help" (but showing a one-line
error message before showing the help of darcs show), but not for "darcs
help show patchindex". Can you also fix the second case?
Are you sure? I get the same result for both. In fact, I think the
--help already filed as expected before this patch and all I did was to
bring the help command on par with --help. I should add a test to make sure.