From: Jeff King <peff@peff.net>
Date: Thu, 22 Jan 2026 19:09:41 GMT
Subject: Re: [PATCH] reset: avoid reflog update on no-op reset
Message-ID: <20260122190941.GB2098026@coredump.intra.peff.net>
In-Reply-To: <xmqqwm19mq69.fsf@gitster.g>

On Thu, Jan 22, 2026 at 10:57:02AM -0800, Junio C Hamano wrote:

> Pushkar Singh <pushkarkumarsingh1970@gmail.com> writes:
> 
> > When "git reset" is invoked with a target that already matches HEAD,
> > it currently writes a reflog entry even though no reference is updated.
> >
> > Detect this no-op case and avoid updating ORIG_HEAD and HEAD, skipping
> > the reflog entry entirely.
> 
> I am mildly negative on this one.  A scripted use that gets which
> commit to reset to from the caller in the outside world, e.g.,
> 
>     #!/bin/sh
>     git reset --hard "$1"
>     git diff --stat @{1}
> 
> would be confused if reflog does not reliably store the state before
> running "reset --hard" to @{1}.  In other words ...
> 
> > Add a regression test to ensure no reflog entry is written for a no-op
> > reset.
> 
> ... this change may already be a regression for existing users.

I was just writing the same message. ;) In addition to scripted use,
that reflog does contain some human-readable information: the message
field tells us what name we "git reset --hard" to. That might be helpful
when digging through it trying to piece together what happened.

-Peff