On Sat, Aug 2, 2025 at 5:46 AM Jeff King [off-list ref] wrote:

On Wed, Jul 30, 2025 at 05:49:29PM -0400, D. Ben Knoble wrote:

quoted

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 "^:<path>" from ":^:<path>", just to complete the
story, is that in setup.c:check_filename() we try to stat whatever
comes after ":^":
- for the former, that's <path> and we are ok
- for the latter, that's :<path>, 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