Re: [PATCH v3 07/12] unpack-trees: stop recursing into sparse directories

> Sorry, I spoke too soon...
> 
> On Mon, May 17, 2021 at 7:03 PM Elijah Newren <newren@gmail.com> wrote:
>>
>>> diff --git a/unpack-trees.c b/unpack-trees.c
>>> index ef6a2b1c951c..703b0bdc9dfd 100644
>>> --- a/unpack-trees.c
>>> +++ b/unpack-trees.c
>>> @@ -1261,6 +1261,7 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
>>>         struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
>>>         struct unpack_trees_options *o = info->data;
>>>         const struct name_entry *p = names;
>>> +       unsigned unpack_tree = 1;
> 
> Here, you set unpack_tree to 1.
> 
>>>
>>>         /* Find first entry with a real name (we could use "mask" too) */
>>>         while (!p->mode)
>>> @@ -1307,7 +1308,8 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
>>>                 }
>>>         }
>>>
>>> -       if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
>>> +       if (unpack_tree &&
> 
> You check it's value here...
> 
>>> +           unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
>>>                 return -1;
>>>
>>>         if (o->merge && src[0]) {
>>> @@ -1337,7 +1339,8 @@ static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, str
>>>                         }
>>>                 }
>>>
>>> -               if (traverse_trees_recursive(n, dirmask, mask & ~dirmask,
>>> +               if (unpack_tree &&
> ...and here....
> 
>>> +                   traverse_trees_recursive(n, dirmask, mask & ~dirmask,
>>>                                              names, info) < 0)
>>>                         return -1;
>>>                 return mask;
> 
> but you never set unpack_tree to 0, so this is wasted effort and you
> always recurse.  The previous iteration had a case where it'd set
> unpack_tree to 0 in a certain case, but you deleted that code in this
> version.  Why?