Re: [PATCH v13 05/12] ref-filter: add option to filter out tags, branches and remotes

> On 08/27/2015 02:42 PM, Karthik Nayak wrote:
>> On Wed, Aug 26, 2015 at 9:40 PM, Michael Haggerty <mhagger@alum.mit.edu> wrote:
>>> On 08/22/2015 05:39 AM, Karthik Nayak wrote:
>>>> [...]
>>>> +     if (type == FILTER_REFS_BRANCHES)
>>>> +             ret = for_each_reftype_fullpath(ref_filter_handler, "refs/heads/", broken, &ref_cbdata);
>>>> +     else if (type == FILTER_REFS_REMOTES)
>>>> +             ret = for_each_reftype_fullpath(ref_filter_handler, "refs/remotes/", broken, &ref_cbdata);
>>>> +     else if (type == FILTER_REFS_TAGS)
>>>> +             ret = for_each_reftype_fullpath(ref_filter_handler, "refs/tags/", broken, &ref_cbdata);
>>>> +     else if (type & FILTER_REFS_ALL) {
>>>> +             ret = for_each_reftype_fullpath(ref_filter_handler, "", broken, &ref_cbdata);
>>>> +             if (type & FILTER_REFS_DETACHED_HEAD)
>>>> +                     head_ref(ref_filter_handler, &ref_cbdata);
>>>
>>> The usual promise of the for_each_ref functions is that they stop
>>> iterating if the function ever returns a nonzero value. So the above
>>> should be
>>>
>>>                 if (! ret && (type & FILTER_REFS_DETACHED_HEAD))
>>>                         ret = head_ref(ref_filter_handler, &ref_cbdata);
>>>
>>> Also, these functions usually iterate in lexicographic order, so I think
>>> you should process HEAD before the others.
>>
>> This is done on purpose, cause we need to print the HEAD ref separately
>> so we print the last ref_array_item in the ref_array, free that memory and
>> sort and print the rest, hence HEAD ref is attached to the last.
>
> Without having looked at the other patches, this makes me wonder whether
> it makes sense to store HEAD in the ref_array at all or whether it
> should be handled separately.
>

>>> But there's another problem here. It seems like
>>> FILTER_REFS_DETACHED_HEAD is only processed if (type & FILTER_REFS_ALL)
>>> is nonzero. But shouldn't it be allowed to process *only* HEAD?
>>>
>>> So, finally, I think this code should look like
>>>
>>>         else if (!filter->kind)
>>>                 die("filter_refs: invalid type");
>>>         else {
>>>                 if (filter->kind & FILTER_REFS_DETACHED_HEAD)
>>>                         ret = head_ref(ref_filter_handler, &ref_cbdata);
>>>                 if (! ret && (filter->kind & FILTER_REFS_ALL))
>>>                         ret =
>>> for_each_reftype_fullpath(ref_filter_handler, "", broken, &ref_cbdata);
>>>         }
>>>
>>
>> So finally something like this perhaps
>>
>>     if (!filter->kind)
>>         die("filter_refs: invalid type");
>>     else {
>>         if (filter->kind == FILTER_REFS_BRANCHES)
>>             ret = for_each_reftype_fullpath(ref_filter_handler,
>> "refs/heads/", broken, &ref_cbdata);
>>         else if (filter->kind == FILTER_REFS_REMOTES)
>>             ret = for_each_reftype_fullpath(ref_filter_handler,
>> "refs/remotes/", broken, &ref_cbdata);
>>         else if (filter->kind == FILTER_REFS_TAGS)
>>             ret = for_each_reftype_fullpath(ref_filter_handler,
>> "refs/tags/", broken, &ref_cbdata);
>>         else if (filter->kind & FILTER_REFS_ALL)
>>             ret = for_each_reftype_fullpath(ref_filter_handler, "",
>> broken, &ref_cbdata);
>>         if (filter->kind & FILTER_REFS_DETACHED_HEAD)
>>             head_ref(ref_filter_handler, &ref_cbdata);
>>     }
>
> Yes, but the last test should be
>
>         if (!ret && (filter->kind & FILTER_REFS_DETACHED_HEAD))
>
> unless you have a reason not to follow the usual convention that a
> nonzero return value from fn means that the iteration should be aborted.
>