Re: [PATCH] archive: fix archive generation for empty trees

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

>> Now, instead of "", we use a pathspec prefix of NULL. If no path
>> arguments were provided, get_pathspec() will return NULL, and we won't
>> try to verify the existence of any paths in the tree.
>
> Yeah, this looks like the right thing to do. The get_pathspec code
> treats a NULL prefix specially as "no prefix", and I think that is what
> we are trying to say here (i.e., we are interpreting pathspecs from the
> root).

Yes, that sounds sane.

> ... However, prefix_pathspec does a lot of magic parsing;
> it's unclear to me whether this is all in support of properly
> adding the prefix, or if its side effects are important.

These "magic" are for things like :(root)/path that will explicitly
refuse the prefix when run from a subdirectory.

In the longer term, get_pathspec() should be converted to directly
deal with "struct pathspec", but we are not there yet.  There are
too many code left-over, even after Duy's last pathspec related
topic, that still look at ->raw field of "struct pathspec" and they
all need to be taught to work with the unified pathspec matching
machinery.  This is one of the lots of unfinished loose ends, which
might be a good GSoC project but may be a bit too large for a
student to bite and chew.