Re: [PATCH] xdiff: implement a zealous diff3

From: Junio C Hamano <gitster@pobox.com>
To: Felipe Contreras <felipe.contreras@gmail.com>,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: "Jeff King" <peff@peff.net>,
	git@vger.kernel.org, "Elijah Newren" <newren@gmail.com>,
	"Johannes Sixt" <j6t@kdbg.org>,
	"Sergey Organov" <sorganov@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Subject: Re: [PATCH] xdiff: implement a zealous diff3
Date: Tue, 15 Jun 2021 11:07:04 +0900	[thread overview]
Message-ID: <xmqq7divzxrr.fsf@gitster.g> (raw)
In-Reply-To: <60c677a2c2d24_f5651208cf@natae.notmuch> (Felipe Contreras's message of "Sun, 13 Jun 2021 16:24:50 -0500")

Felipe Contreras <felipe.contreras@gmail.com> writes:

> I found the problem, m->chg0 was not initialized in xdl_refine_conflicts.
>
> I'm not familiar with the area so I don't know if the following makes
> sense, but it fixes the crash:

Unlike the remainder of the xdiff/ directory, xdiff/xmerge.c was
Dscho's brainchild if I am not mistaken, so I'm CCing him for
input.

> --- a/xdiff/xmerge.c
> +++ b/xdiff/xmerge.c
> @@ -333,7 +333,7 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
>                 mmfile_t t1, t2;
>                 xdfenv_t xe;
>                 xdchange_t *xscr, *x;
> -               int i1 = m->i1, i2 = m->i2;
> +               int i0 = m->i0, i1 = m->i1, i2 = m->i2;
>  
>                 /* let's handle just the conflicts */
>                 if (m->mode)
> @@ -384,6 +384,8 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
>                         m->next = m2;
>                         m = m2;
>                         m->mode = 0;
> +                       m->i0 = i0;
> +                       m->chg0 = 0;
>                         m->i1 = xscr->i1 + i1;
>                         m->chg1 = xscr->chg1;
>                         m->i2 = xscr->i2 + i2;