From: Jeff Hostetler <git@jeffhostetler.com>
Date: Thu, 23 Mar 2023 14:32:00 GMT
Subject: Re: [PATCH 4/4] unpack-trees: take care to propagate the split-index flag
Message-ID: <5a6e83e6-c14b-f2bb-5ec1-669ee7d246c8@jeffhostetler.com>
In-Reply-To: <3963d3e542896b9cdf871dc7ea13330ddac87795.1679500859.git.gitgitgadget@gmail.com>



On 3/22/23 12:00 PM, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> When copying the `split_index` structure from one index structure to
> another, we need to propagate the `SPLIT_INDEX_ORDERED` flag, too, if it
> is set, otherwise Git might forget to write the shared index when that
> is actually needed.
> 
> It just so _happens_ that in many instances when `unpack_trees()` is
> called, the result causes the shared index to be written anyway, but
> there are edge cases when that is not so.
> 
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>   unpack-trees.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/unpack-trees.c b/unpack-trees.c
> index 90b92114be8..ca5e47c77c0 100644
> --- a/unpack-trees.c
> +++ b/unpack-trees.c
> @@ -1916,6 +1916,8 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
>   		 * create a new one.
>   		 */
>   		o->result.split_index = o->src_index->split_index;
> +		if (o->src_index->cache_changed & SPLIT_INDEX_ORDERED)
> +			o->result.cache_changed |= SPLIT_INDEX_ORDERED;

Nice find!

>   		o->result.split_index->refcount++;
>   	} else {
>   		o->result.split_index = init_split_index(&o->result);