Re: Bug or unexpected behaviour in git show <rev>:a\b

> Subject: verify_filename(): handle backslashes in "wildcards are pathspecs" rule
>
> Commit 28fcc0b71a (pathspec: avoid the need of "--" when wildcard is
> used, 2015-05-02) allowed:
>
>   git rev-parse '*.c'
>
> without the double-dash. But the rule it uses to check for wildcards
> actually looks for any glob special. This is overly liberal, as it means
> that a pattern that doesn't actually do any wildcard matching, like
> "a\b", will be considered a pathspec.
>
> If you do have such a file on disk, that's presumably what you wanted.
> But if you don't, the results are confusing: rather than say "there's no
> such path a\b", we'll quietly accept it as a pathspec which very likely
> matches nothing (or at least not what you intended). Likewise, looking
> for path "a\*b" doesn't expand the search at all; it would only find a
> single entry, "a*b".
>
> This commit switches the rule to trigger only when glob metacharacters
> would expand the search, meaning both of those cases will now report an
> error (you can still disambiguate using "--", of course; we're just
> tightening the DWIM heuristic).