git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Johannes Schindelin <johannes.schindelin@gmx.de>
Cc: git@vger.kernel.org, Naja Melan <najamelan@autistici.org>
Subject: Re: [PATCH 2/2] diff: fix a double off-by-one with --ignore-space-at-eol
Date: Mon, 11 Jul 2016 12:01:33 -0700	[thread overview]
Message-ID: <xmqqeg709eya.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <daf43539479acdebe1c5799c38f3be75c2399feb.1468048754.git.johannes.schindelin@gmx.de> (Johannes Schindelin's message of "Sat, 9 Jul 2016 09:23:55 +0200 (CEST)")

Johannes Schindelin <johannes.schindelin@gmx.de> writes:

> diff --git a/xdiff/xutils.c b/xdiff/xutils.c
> index 62cb23d..027192a 100644
> --- a/xdiff/xutils.c
> +++ b/xdiff/xutils.c
> @@ -200,8 +200,10 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
>  				return 0;
>  		}
>  	} else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
> -		while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++])
> -			; /* keep going */
> +		while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
> +			i1++;
> +			i2++;
> +		}
>  	}

When we notice l1[i1] and l2[i2] does not match, we want i1 and i2
to stay pointing at that unmatch.  The code before this fix however
ends up incrementing them before leaving the loop.

This breakage seems to come from 2344d47f (diff: fix 2 whitespace
issues, 2006-10-12)?  That's quite old and it is somewhat surprising
that nobody complained.

Well spotted.  Will queue.

Thanks.




      parent reply	other threads:[~2016-07-11 19:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-09  7:23 [PATCH 0/2] Fix xdiff's --ignore-space-at-eol handling Johannes Schindelin
2016-07-09  7:23 ` [PATCH 1/2] diff: demonstrate a bug with --patience and --ignore-space-at-eol Johannes Schindelin
2016-07-09  7:23 ` [PATCH 2/2] diff: fix a double off-by-one with --ignore-space-at-eol Johannes Schindelin
2016-07-09  7:28   ` Naja Melan
2016-07-11 19:01   ` Junio C Hamano [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqqeg709eya.fsf@gitster.mtv.corp.google.com \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=johannes.schindelin@gmx.de \
    --cc=najamelan@autistici.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).