Re: Using --term-* with bisect breaks skip

From: Junio C Hamano <gitster@pobox.com>
To: Trygve Aaberge <trygveaa@gmail.com>
Cc: git@vger.kernel.org,
	Christian Couder <christian.couder@gmail.com>,
	Pranit Bauva <pranit.bauva@gmail.com>
Subject: Re: Using --term-* with bisect breaks skip
Date: Mon, 19 Apr 2021 11:55:42 -0700	[thread overview]
Message-ID: <xmqqlf9e9k9d.fsf@gitster.g> (raw)
In-Reply-To: <20210418151459.GC10839@aaberge.net> (Trygve Aaberge's message of "Sun, 18 Apr 2021 17:14:59 +0200")

Trygve Aaberge <trygveaa@gmail.com> writes:

> What did you do before the bug happened? (Steps to reproduce your issue)
> 1. git bisect start --term-new=fixed --term-old=unfixed master HEAD~10
> 2. git bisect skip
>
> What did you expect to happen? (Expected behavior)
> Git should mark the commit as skipped and change HEAD to a different commit.
>
> What happened instead? (Actual behavior)
> The commit was marked as skipped, but HEAD was not changed.
>
> What's different between what you expected and what actually happened?
> After running bisect skip, HEAD was still at the same commit as before,
> instead of having changed to a new that I can test. The usual output about
> steps left to test and the new commit was also missing, skip did not output
> anything.
>
> Anything else you want to add:
> - If I don't provide any --term-* options, skip works as expected.
> - The revisions provided in the reproduction steps doesn't matter, they're
>   just an example.
> - I tried running from the next branch, and it happened there too.
>
> [System Info]
> git version:
> git version 2.31.1

Thanks for a report.

I suspect that this is a fairly recent regression.  With Git 2.30.2,
"bisect skip" does flip HEAD and mark the commit to as untestable.

Can you "bisect" the problem?  There aren't that many commits that
touched bisection code during the period.

$ git log --format='%aN %s' --no-merges v2.30.2..v2.31.1 -- \
  bisect.c builtin/bisect--helper.c git-bisect.sh
Jeff King bisect: peel annotated tags to commits
René Scharfe use CALLOC_ARRAY
Johannes Sixt replace "parameters" by "arguments" in error messages
Pranit Bauva bisect--helper: retire `--check-and-set-terms` subcommand
Pranit Bauva bisect--helper: reimplement `bisect_skip` shell function in C
Pranit Bauva bisect--helper: retire `--bisect-auto-next` subcommand
Pranit Bauva bisect--helper: use `res` instead of return in BISECT_RESET case option
Pranit Bauva bisect--helper: retire `--bisect-write` subcommand
Pranit Bauva bisect--helper: reimplement `bisect_replay` shell function in C
Pranit Bauva bisect--helper: reimplement `bisect_log` shell function in C
Martin Ågren hash-lookup: rename from sha1-lookup