Re: [PATCH 1/2] Update :/abc ambiguity check

[Duy Nguyen <pclouds@gmail.com>]

On Tue, Jan 22, 2013 at 2:27 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> :/abc may mean two things:
>>
>> - as a revision, it means the revision that has "abc" in commit
>>   message.
>>
>> - as a pathpec, it means "abc" from root.
>>
>> Currently we see ":/abc" as a rev (most of the time), but never see it
>> as a pathspec even if "abc" exists and "git log :/abc" will gladly
>> take ":/abc" as rev even it's ambiguous. This patch makes it:
>>
>> - ambiguous when "abc" exists on worktree
>> - a rev if abc does not exist on worktree
>> - a path if abc is not found in any commits (although better use
>
> The "any commits" above sounds very scary. Are you really going to
> check against all the commits?

If I remember correctly :/ will search through commit chains until it
finds a commit that matches. So :/non-existent-string definitely
searches through all commits.

>>   "--" to avoid ambiguation because searching through commit DAG is
>>   expensive)
>>
>> A plus from this patch is, because ":/" never matches anything as a
>> rev, it is never considered a valid rev and because root directory
>> always exists, ":/" is always unambiguously seen as a pathspec.
>
> That is the primary plus in practice, I think, and it is a big one.
>
> When naming a directory that belongs to a different subdirectory
> hierarchy, typing ":/that/directory/name" is not any easier than
> having your shell help you complete "../../that/directory/name"; I
> suspect nobody uses the relative-to-root notation to name anything
> but the root in real life.

As I noted in the patch comment, I do copy/paste repo-absolute paths
from a diff quite often (just skip the "a" and "b" prefix). Sometimes
I hope "git diff" has an option to produce relative paths..
-- 
Duy