Re: [RFC PATCH v1 1/2] pathspec: warn: long and short forms are incompatible

We avoid using variable-length arrays in our codebase. ...

Hear hear, however, I wanted to avoid the "small mess"
that allocate/free would cause (one or more of ++sloc, labels, if-nesting); ...

But two, they are limited in size and the failure mode is not graceful. ...

... however, my main issue is that - I don't know what's a sane allocation size.

... The "4096" is scary here ...

While scary, it is "a safe" upper high.
The first time the string ends up in pathspec.c for processing it's here:
	entry = argv[i];
which comes from here
	parse_pathspec(pathspec, magic_mask, flags, prefix, parsed_file.v);

and I don't know what's the maximum size of `parsed_file.v[0]`

Is this "%4096[^)]" actually valid? I don't think scanf understands
regular expressions.

I was suprised too - but it's not regex.

see: https://www.cplusplus.com/reference/cstdio/scanf/#parameters - 4th/3rd row from the end

%s is greedy and there would be no other way to limit `sscanf` to not include `)` on its first variable.

... though I'm not sure I understand what that is looking for ...

I think it will help you see what I am trying to achieve if you read at the warning message / testcase
https://lore.kernel.org/git/20210326024005.26962-2-stdedos+git@gmail.com/#iZ30t:t6132-pathspec-exclude.sh (local)

And, to clean up the testcase:
	git log --oneline --format=%s -- ':!(glob)**/file'

I guess it should be now obvious what am I targetting:

If someone naively mixes short and long pathspec magics (`!`, and `(glob)`),
short form takes precedence and ignores long magic / assumes long magic as part of path.

(If it's not obvious, all the more reason to include such warning)