Re: [PATCH 2/5] pathspec: add tree_recursive_diff parameter

[Nguyen Thai Ngoc Duy <pclouds@gmail.com>]

2010/9/28 Junio C Hamano <gitster@pobox.com>:
> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> When wildcard match is implemented, a full path is needed to do final
>> match. What type of diff_tree is performed determines how to treat
>> directories:
>>
>>  - If it's recursive diff, directories are just an intermediate step.
>>    All path must end with a file name. Thus, directories will be
>>    unconditionally matched.
>
> Hmm, I am not sure what you mean by this.  If the pathspec says a/b*/c,
> you are in "a" and are deciding if you should descend to its subdirectory,
> then you would surely want to be able to say:
>
>  (1) Ah, the subdirectory I am looking at is "bar" and it does match "b*".
>     It might contain "c"; I should descend into it.
>
>  (2) Nope, the subdirectory I am looking at is "frotz" and it can never
>     match "b*", so there is no point recursing into it.
>

I did not go that far, trying to analyse the pattern. When I wrote
"immediate step" I was thinking of "*foo" pattern, which effectively
means descending to any reachable directories because '*' matches
slashes too. I think that's the worst case.

Anyway I did not know that I could borrow some optimizations from
pathspec_matches() in builtin/grep.c.
-- 
Duy