From: Maxim Kuvyrkov Date: Mon, 16 Dec 2019 13:22:52 GMT Subject: Re: [BUG] Git bisect extends bisecting range on repeated good/bad data Message-ID: <7A220DC9-C654-40E9-8F04-7B9B3ED3318D@linaro.org> In-Reply-To: > On Dec 13, 2019, at 9:58 PM, Junio C Hamano wrote: > > Maxim Kuvyrkov writes: > >> Git bisect may /extend/ bisection range on repeated good/bad data. Is this expected? > > It is not "repeated" that is an issue, but yes this is expected. > > The bisection works by finding a mid point to cut the graph into two > pieces of roughly the same size, and the graph is defined by the > set of good commits on the bottom (i.e. "we were told that all these > good commits were good, so there is no point going back the history > beyond any of them") and the single "bad" commit you gave the last. > > If you give 'bad' that is in the newer part of the history than the > one that is already known to be bad, then you rewind that single > "bad" commit, to force/allow the machinery to recompute the midpoint > [*1*], and because the area to search would be wider when you do so, > it is very much expected that you'd be offered to test more commits. > > > > [Footnote] > > *1* I said force/allow is because allowing the machinery to go back > and recompute is a way to recover when you gave a "bad" earlier > by mistake. > Hi Junio, Thank you for the answer. -- Maxim Kuvyrkov https://www.linaro.org