Re: [PATCH v4 3/4] cache-tree: fix writing cache-tree when CE_REMOVE is present

From: Nguyen Thai Ngoc Duy <pclouds@gmail.com>
Date: Dec 16, 2012, 10:15 UTC
Message-ID: <CACsJy8DgwQ2jn=tPpE8f22JNE1Vih86d=Xf1iGBznLcwMukd+w@mail.gmail.com>
In-Reply-To: <7vk3siqx8b.fsf@alter.siamese.dyndns.org>

On Sun, Dec 16, 2012 at 2:20 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 15 quoted lines

> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> entry_count is used in update_one() for two purposes:
>>
>> 1. to skip through the number of processed entries in in-memory index
>> 2. to record the number of entries this cache-tree covers on disk
>>
>> Unfortunately when CE_REMOVE is present these numbers are not the same
>> because CE_REMOVE entries are automatically removed before writing to
>> disk but entry_count is not adjusted and still counts CE_REMOVE
>> entries.
>
> Nicely explained.  I wonder if we can also add a piece of test to
> the patch 4/4 to demonstrate the issue with CE_REMOVE entries,
> though.

A hand crafted one, maybe. I did not attempt to recreate it with git commands (and I don't think we update cache-tree after unpack_trees). So I wrote something like this instead:

int main(int ac, char **av)
{
	unsigned char sha1[20];
	setup_git_directory();
	read_cache();
	active_cache[1]->ce_flags |= CE_REMOVE;
	write_cache_as_tree(sha1, 0, NULL);
	return 0;
}

I can polish it a bit and write new tests based on it and test-dump-cache-tree if you want.

-- 
Duy