Re: [PATCH v1 03/19] split-index: add {add,remove}_split_index() functions

[Christian Couder <christian.couder@gmail.com>]

On Tue, Oct 25, 2016 at 11:58 AM, Duy Nguyen <pclouds@gmail.com> wrote:
> On Sun, Oct 23, 2016 at 4:26 PM, Christian Couder
> <christian.couder@gmail.com> wrote:
>> +void remove_split_index(struct index_state *istate)
>> +{
>> +       if (istate->split_index) {
>> +               /*
>> +                * can't discard_split_index(&the_index); because that
>> +                * will destroy split_index->base->cache[], which may
>> +                * be shared with the_index.cache[]. So yeah we're
>> +                * leaking a bit here.
>
> In the context of update-index, this is a one-time thing and leaking
> is tolerable. But because it becomes a library function now, this leak
> can become more serious, I think.
>
> The only other (indirect) caller is read_index_from() so probably not
> bad most of the time (we read at the beginning of a command only).
> sequencer.c may discard and re-read the index many times though,
> leaking could be visible there.

So is it enough to check if split_index->base->cache[] is shared with
the_index.cache[] and then decide if discard_split_index(&the_index)
should be called?

Thanks,
Christian.