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From: Ephrim Khong <dr.khong@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: GIT Mailing-list <git@vger.kernel.org>
Subject: Re: [Bug] data loss with cyclic alternates
Date: Sun, 13 Jul 2014 12:44:25 +0200	[thread overview]
Message-ID: <53C26309.5040401@gmail.com> (raw)
In-Reply-To: <xmqqy4vz51gb.fsf@gitster.dls.corp.google.com>

Am 11.07.14 18:01, schrieb Junio C Hamano:
> Ephrim Khong <dr.khong@gmail.com> writes:
>
>> git seems to have issues with alternates when cycles are present (repo
>> A has B/objects as alternates, B has A/objects as alternates).
>
> Yeah, don't do that.  A thinks "eh, the other guy must have it" and
> B thinks the same.  In general, do not prune or gc a repository
> other repositories borrow from, even if there is no cycle, because
> the borrowee does not know anythning about objects that it itself no
> longer needs but are still needed by its borrowers.

It seems that there is a safeguard against this in sha1_file.c, 
link_alt_odb_entry(), that doesn't work as intended:

	if (!strcmp(ent->base, objdir)) {
		free(ent);
		return -1;
	}

However, printf-debugging tells me that ent->base is absolute and objdir 
is relative (".git/objects") at this point, so the strings are different 
even though the files are the same.

I never submitted a patch to git. Do you think someone can fix this 
hickup, otherwise I'll give it a shot next week.

  parent reply	other threads:[~2014-07-13 10:44 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-11  9:37 [Bug] data loss with cyclic alternates Ephrim Khong
2014-07-11 16:01 ` Junio C Hamano
2014-07-11 18:01   ` Keller, Jacob E
2014-07-12  5:57     ` Jeff King
2014-07-14 22:05       ` Keller, Jacob E
2014-07-13 10:44   ` Ephrim Khong [this message]
2014-07-14  9:02     ` [PATCH] sha1_file: do not add own object directory as alternate Ephrim Khong
2014-07-14 10:47       ` Duy Nguyen
2014-07-14 12:53         ` [PATCH v2] " Ephrim Khong
2014-07-15  5:44           ` Johannes Sixt
2014-07-15 11:29             ` [PATCH v3] " Ephrim Khong
2014-07-15 19:26               ` Junio C Hamano
2014-07-16  6:42                 ` Ephrim Khong
2014-07-15 19:33               ` Eric Sunshine
2014-07-15 19:48               ` Junio C Hamano
2014-07-16  6:47                 ` Ephrim Khong

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