Re: Bug: magic-less pathspecs that start with ":" not processed as expected.

From: Jeff King <peff@peff.net>
Date: Nov 6, 2023, 17:31 UTC
Message-ID: <20231106173133.GC10414@coredump.intra.peff.net>
In-Reply-To: <CAMmZTi-JJ6=Uw_+r50hKMYf34D0NtqXhaA=f+11+wAQBjqA7_g@mail.gmail.com>

On Mon, Nov 06, 2023 at 10:54:03AM -0500, Joanna Wang wrote:

Show 19 quoted lines

> What did you do before the bug happened? (Steps to reproduce your issue)
> 
> What did you expect to happen? (Expected behavior)
> `git stash push -- :file` where `:` is part of the filename, should search
> for files named ":file"
> 
> What happened instead? (Actual behavior)
> The match string used to find files is "file" without the ":".
> 
> What's different between what you expected and what actually happened?
> file named ":file" is not found.
> 
> Anything else you want to add:
> I believe this is due to parse_short_magic() not handling the case where
> ":" is part of the file name rather than a prefix for pathspec magic.
> 
> I could not find any documentation that says ":" is a reserved
> character to indicate pathspec magic symbols MUST follow or that
> ":file" is not a valid file name.

I think this is the correct behavior according to the documentation. From "git help glossary", the entry on "pathspec" says:

  A pathspec that begins with a colon : has special meaning. In the
  short form, the leading colon : is followed by zero or more "magic
  signature" letters (which optionally is terminated by another colon
  :), and the remainder is the pattern to match against the path.

So ":file" just has zero magic signature letters. I think you want:

  :::file

which of course is rather ugly, but then so is your filename. ;) Although longer, probably this is more readable:

  :(literal):file

And if you're working with a lot of such files (or you are scripting and know you have a set of filenames), then your best bet is probably turning on literal mode, like:

  git --literal-pathspecs ls-files -- :file

-Peff

PS It took me a while to figure out where we document pathspec syntax. I
   wonder if a "gitpathspecs" manpage would make sense, like we have
   "gitrevisions".