Re: [PATCH v2 2/3] unpack-trees: increment cache_bottom for sparse directories

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 21, 2022, 20:52 UTC
Message-ID: <xmqqr16vvxhy.fsf@gitster.g>
In-Reply-To: <df403c7b-5152-492a-96b5-575ccc1520de@github.com>

Derrick Stolee <derrickstolee@github.com> writes:

Show 19 quoted lines

> On 3/17/2022 11:55 AM, Victoria Dye via GitGitGadget wrote:
>> From: Victoria Dye <vdye@github.com>
>> 
>> Correct tracking of the 'cache_bottom' for cases where sparse directories
>> are present in the index.
>
> Thank you for the detailed background (that I cut from my reply).
>
>> CORRECTING CACHE_BOTTOM
>> -----------------------
>> The problems observed in 't1092' come from 'cache_bottom' lagging behind in
>> cases where the cache tree-based advancement doesn't occur. To solve this,
>> then, the fix in 17a1bb570b is "reversed"; rather than skipping
>> 'cache_bottom' advancement in 'mark_ce_used()', we skip the directory
>> contents-based advancement for sparse directories. Now, every index entry
>> can be accounted for in 'cache_bottom':
>
> I have sufficient background to be confident that you are doing the
> right thing here!

;-)

The "partly lagging" walking of the index guided by cache_bottom has been a tricky thing in the unpack_trees machinery, and I am very happy that we now have two more experts on the topic ;-)

Thanks, both.