Re: [PATCH] cache-tree: invalidate i-t-a paths after writing trees

> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> diff --git a/cache-tree.c b/cache-tree.c
>> index 28ed657..30a8018 100644
>> --- a/cache-tree.c
>> +++ b/cache-tree.c
>> @@ -381,6 +381,9 @@ int cache_tree_update(struct cache_tree *it,
>>       i = update_one(it, cache, entries, "", 0, flags);
>>       if (i < 0)
>>               return i;
>> +     for (i = 0; i < entries; i++)
>> +             if (cache[i]->ce_flags & CE_INTENT_TO_ADD)
>> +                     cache_tree_invalidate_path(it, cache[i]->name);
>>       return 0;
>>  }
>
> I notice there is another special case for CE_REMOVE but there is
> nothing that adjusts the cache-tree for these entries in the current
> codebase.
>
> I suspect the original code before we (perhaps incorrectly) updated
> the code not to error out upon I-T-A entries was fine only because
> we do not attempt to fully populate the cache-tree during a merge in
> the unpack-trees codepath, which will mark the index entries that
> are to be removed with CE_REMOVE in the resulting index.
>
> The solution implemented with this patch will break if we start
> updating the cache tree after a successful merge in unpack-trees, I
> suspect.

> An alternative might be to add a "phoney" bit next to "used" in the
> cache_tree structure, mark the cache tree as phoney when we skip an
> entry marked as CE_REMOVE or CE_ITA, and make the postprocessing
> loop this patch adds aware of that bit, instead of iterating over
> the index entries; instead, it would recurse the resulting cache
> tree and invalidate parts of the tree that have subtrees with the
> "phoney" bit set, or something.