Re: [PATCH v2] builtin/repack.c: invalidate MIDX only when necessary

[Junio C Hamano <gitster@pobox.com>]

Derrick Stolee <stolee@gmail.com> writes:

> On 8/25/2020 12:04 PM, Taylor Blau wrote:
>> In 525e18c04b (midx: clear midx on repack, 2018-07-12), 'git repack'
>> learned to remove a multi-pack-index file if it added or removed a pack
>> from the object store.
>> 
>> This mechanism is a little over-eager, since it is only necessary to
>> drop a MIDX if 'git repack' removes a pack that the MIDX references.
>> Adding a pack outside of the MIDX does not require invalidating the
>> MIDX, and likewise for removing a pack the MIDX does not know about.
>> 
>> Teach 'git repack' to check for this by loading the MIDX, and checking
>> whether the to-be-removed pack is known to the MIDX. This requires a
>> slightly odd alternation to a test in t5319, which is explained with a
>> comment. A new test is added to show that the MIDX is left alone when
>> both packs known to it are marked as .keep, but two packs unknown to it
>> are removed and combined into one new pack.
>> 
>> Helped-by: Derrick Stolee <dstolee@microsoft.com>
>> Signed-off-by: Taylor Blau <me@ttaylorr.com>
>> ---
>> Range-diff against v1:
>
> I know this thread went in a new direction about pack-redundant and
> dashed-git, but this version looks good to me. I wanted to make sure
> it wasn't lost in the shuffle.

Very much appreciated.  I was wondering if I'll see a final reroll
or v2 already had all we wanted.

Thanks.