Re: git bisect do not work when good reversion is newer than bad reversion

> "Cai, Crane" <Crane.Cai@amd.com> writes:
> 
>> Hi Junio,
>>
>> Sorry to disturb you. Here the requirement I met can not find answer
>> from website. That's why I directly ask you.
>>
>> I need to use "git bisect" to find what patch can fix a problem.
>> I found v2.6.25 has this problem.
>> And v2.6.26 does NOT has this problem.
>>
>> Then I use bisect as this:
>>
>> #git bisect start
>> #git bisect good v2.6.26
>> #git bisect bad v2.6.25
>>
>> No reversion cut via these steps. Do you know whether git command can
>> achieve this requirement or not?
> 
> You can use "git bisect" to find a single change that fixed the issue
> (_provided if_ such a single change exists).  There is a small mental
> trick you need to exercise.
> 
> First, realize that bisect is about "it used to be like this, but later it
> turned into that.  Where did that single transition from this to that
> happened"?  Usually, "this" is "had this particular bug and was broken"
> and "that" is "that bug was fixed and things work smoothly".  In your
> case, however, "this" is "broken" and "that" is "fixed".  IOW, the
> question you ask "bisect" is "it used to be broken but later it was fixed;
> where did that exactly happen?".
> 
> The mental trick is to swap "good" and "bad" in order to adjust to your
> use, because you are using bisect in a reverse way from the usual.  Usual
> case uses "good" mark "this" while "bad" is used to mark "that" in the
> sentence "it used to be like this, but later it turned into that".
> 
> So what you would do is...
> 
> 	(1) First of all, write on a piece of paper:
> 
> 	    good - the version _STILL_ has the bug.
>             bad  - the version does not have the bug _ANYMORE_
> 
> 	(2) Start with "git bisect v2.6.25 v2.6.26";
> 
>         (3) As you test each revision, look at the memo you made.  Say
>             "good" if it still has the bug you are interested in; say
>             "bad" if it does not have the bug anymore..
> 
>     cf. http://thread.gmane.org/gmane.comp.version-control.git/86063
>