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From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: Christoph Mallon <mallon@cs•uni-saarland.de>,
	Jonathan Nieder <jrnieder@gmail•com>,
	git@vger•kernel.org, Stefan Beller <sbeller@google•com>
Subject: Re: Bug in reflog of length 0x2BFF
Date: Thu, 04 Dec 2014 14:14:50 -0800	[thread overview]
Message-ID: <xmqq388vrrj9.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <20141204215805.GD19953@peff.net> (Jeff King's message of "Thu, 4 Dec 2014 16:58:05 -0500")

Jeff King <peff@peff•net> writes:

> I think the bug is in the reverse-reflog reader in
> for_each_reflog_ent_reverse. It reads BUFSIZ chunks of the file in
> reverse order, and then parses them individually. If the trailing
> newline for a line falls directly on the block boundary, we may not have
> it in our current block, and pass the line to show_one_reflog_ent
> without a trailing newline.

Ahh, thanks for helping spot it.  A code that uses BUFSIZ explains
why a single reproduction recipe is platform dependent.

> So this is a long-standing bug in for_each_reflog_ent_reverse. It just
> showed up recently because we started using that function for
> read_ref_at_ent.
> ...
> The above is a workaround. I think the right solution is probably to
> teach for_each_reflog_ent_reverse to makes sure the trailing newline is
> included (either by tweaking the reverse code, or conditionally adding
> it to the parsed buffer).

Sounds correct.  Unfortunately I no longer remember how I decided to
deal with a line that spans the block boundary in that piece of code
X-<.

  reply	other threads:[~2014-12-04 22:14 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-01 15:15 Bug in reflog of length 0x2BFF Christoph Mallon
2014-12-01 16:00 ` Christoph Mallon
2014-12-01 18:53   ` Stefan Beller
2014-12-01 22:30     ` Christoph Mallon
2014-12-01 23:35 ` Jonathan Nieder
2014-12-02  1:39   ` Stefan Beller
2014-12-02  6:13   ` Christoph Mallon
2014-12-04 20:18   ` Junio C Hamano
2014-12-04 20:37     ` Christoph Mallon
2014-12-04 21:58       ` Jeff King
2014-12-04 22:14         ` Junio C Hamano [this message]
2014-12-05  1:28           ` [PATCH] for_each_reflog_ent_reverse: fix newlines on block boundaries Jeff King
2014-12-05  1:32             ` [PATCH] for_each_reflog_ent_reverse: turn leftover check into assertion Jeff King
2014-12-05 19:15               ` Junio C Hamano
2014-12-04 22:10       ` Bug in reflog of length 0x2BFF Junio C Hamano

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