From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 1/8] fixup! combine_diff: simplify intersect_paths() further
Date: Mon, 03 Feb 2014 11:40:18 -0800
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References: <cover.1391430523.git.kirr@mns.spb.ru>
	<60ec61bdd2ef3cba7537e29c42f9c8a810da245d.1391430523.git.kirr@mns.spb.ru>
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To: Kirill Smelkov <kirr@mns.spb.ru>
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In-Reply-To: <60ec61bdd2ef3cba7537e29c42f9c8a810da245d.1391430523.git.kirr@mns.spb.ru>
	(Kirill Smelkov's message of "Mon, 3 Feb 2014 16:47:15 +0400")
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Kirill Smelkov <kirr@mns.spb.ru> writes:

> That cleanup patch is good, but I've found a bug in it. In the item removal
> code
>
>> +                      /* p->path not in q->queue[]; drop it */
>> +                      struct combine_diff_path *next = p->next;
>> +
>> +                      if ((*tail = next) != NULL)
>> +                              tail = &next->next;
>> +                      free(p);
>>                        continue;
>
>         *tail = next
>
> is right, but
>
>         tail = &next->next
>
> is wrong,

Heh, surely.  We just have skipped, and the fact that tail points at
the pointer variable that points at the first of the remaining items
does not change with this skipping of next by assigning it to *tail.  
An extra assignment to tail will skip one more, which is unnecessary.