[BUG] (firsttupleslot)==NULL is redundant or is possible nulldereference? - Mailing list pgsql-hackers

Hi,
This is real bug? firsttupleslot == NULL.

\backend\executor\nodeGroup.c
    if (TupIsNull(firsttupleslot))
    {
        outerslot = ExecProcNode(outerPlanState(node));
        if (TupIsNull(outerslot))
        {
            /* empty input, so return nothing */
            node->grp_done = true;
            return NULL;
        }
        /* Copy tuple into firsttupleslot */
        ExecCopySlot(firsttupleslot, outerslot);

include\executor\tuptable.h:
#define TupIsNull(slot) \
    ((slot) == NULL || TTS_EMPTY(slot))

static inline TupleTableSlot *
ExecCopySlot(TupleTableSlot *dstslot, TupleTableSlot *srcslot)
{
    Assert(!TTS_EMPTY(srcslot));

    dstslot->tts_ops->copyslot(dstslot, srcslot);

    return dstslot;
}