Re: [PATCH] bisect: test merge base if good rev is not an ancestor of bad rev

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

Christian Couder <chriscool@tuxfamily.org> writes:

> Yeah, in that case...
>
>> The whole idea of "bisect" relies on that idea, that any ancestor of a
>> good commit is good.  Otherwise you'd have to check the commits one by
>> one, not in a bisecting manner.

Didn't we already discuss this at length?

> No, you just need to check that the merge bases between the bad rev on one 
> side and each good rev on the other side are good too. And if that is the 
> case, then you can be sure that bisection will point to a first bad commit.
>
> So the choice is between a simple and fast but not fully reliable bisect, or 
> a more complex and slower but fully reliable bisect.

I have not looked at your implementation, but I do not think:

 - The current one is not "fully reliable"; the user needs to know what
   he is doing.  You might call it "prone to user errors".

 - "Test this merge-base before going forward, please" will add typically
   only one round of check (if you have more merge bases between good and
   bad, you need to test all of them are good to be sure), so it is not
   "slower nor more complex".