git bisect for reachable commits only

Hi all,

I just found an interesting post how git bisect can trouble humans. Full story is here https://groups.google.com/forum/#!topic/git-users/v3__t42qbKE

My suggestion to fix it (ditto)

What I suggest change logic of bisecting to something like

      git config bisect.reachable true

This behaviour will reduce bisecting only to reachable commits between bad/good points and will never goes away.

Maybe if commit will be found at merge commit git bisect can suggest open another round trip to looking into not reachable way, but anyway it should be explicit confirmed by user.

BTW, if bad commit is merge point with more than 2 parents, how git bisect will find "first wrong commit" at the current state?

Thanks for the attention,

Oleg