Re: Blaming diffs

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

Christian Couder <chriscool@tuxfamily.org> writes:

> Le lundi 17 septembre 2007, Shawn O. Pearce a écrit :
>> Christian Couder <chriscool@tuxfamily.org> wrote:
>> > I don't know if that's what you are looking for but perhaps you could
>> > use "git bisect run". You just need to pass it a script that returns 1
>> > when it finds the changes and 0 otherwise. (See git-bisect man page.)
>>
>> That's very inefficient to search for something...
>
> Perhaps but you can search using whatever script or command you want/know. 
> You are not limited by those implemented in git.
>
> You can also make it more efficient with "git bisect {start,good,bad}".

I _think_ the inefficiency Shawn refers to is that "git bisect"
wrapper inherently is based on checking out the revision.  It is
similar to "filter-branch --tree-filter" being much more
inefficient than "filter-branch --index-filter" (the latter only
works with index while the former does a full checkout).

The underlying "git rev-list --bisect" can be used to ask for
sequence of commits to check if your check does not require a
full checkout, but there is no wrapper like "git bisect" that 
uses that mode of operation.