From: D. Ben Knoble Date: Sat, 02 Aug 2025 16:13:25 GMT Subject: Re: Why does git-grep appear to treat exclude pathspecs differently? Message-ID: In-Reply-To: <20250802094657.GG3711639@coredump.intra.peff.net> On Sat, Aug 2, 2025 at 5:46 AM Jeff King wrote: > > On Wed, Jul 30, 2025 at 05:49:29PM -0400, D. Ben Knoble wrote: > > > which eventually dies as noted. However: > > > > - looks_like_pathspec() only checks for long magic, as you noted > > - setup.c:check_filename() looks for short-magic, too, but only > > considers ":^" to work like a pathname if we're excluding everything? > > > > I think what I find confusing is that, while this is definitely a DWIM > > case for git-grep, it doesn't seem to do DWIM :) We are verifying that > > the remaining arguments are filenames, but couldn't they really be > > full pathspecs, as long as they aren't revisions? > > > > The difference for "^:" from ":^:", just to complete the > > story, is that in setup.c:check_filename() we try to stat whatever > > comes after ":^": > > - for the former, that's and we are ok > > - for the latter, that's :, fail. > > > > So it seems like the places that check for short-magic should also > > consider the optional trailing colon? > > Yeah, I'd think so. But it's worse than that, even. According to the > glossary definition you showed: > > In the short form, the leading colon `:` is followed by zero or more > "magic signature" letters (which optionally is terminated by another > colon `:`) > > we allow multiple bits of magic. So the code in check_filename() that > looks for ":/", ":^", etc would be fooled when seeing more than one > character, like: ":/^exclude-from-root". AFAICT there are only two short > magic types, so I guess nobody has really run into this before. Good call out! I also see only 2 magic items (one with a synonym) at the moment. > > Also, I guess this function ought to be respecting the literal_pathspecs > global? The actual pathspec parser does. > > If we can, we probably ought to be feeding the paths to a function like > pathspec.c:parse_element_magic() and then checking the resulting flags > (and skipping past the prefix as it indicates). Thanks for pointing me at this; maybe I'll find some time for patches unless someone beats me to it. > > -Peff > > PS I didn't even know that we allowed multiple short items or a trailing > colon until your email! Hidden corners of Git. ;) -- D. Ben Knoble