Function getfreepos

third-party/lua-5.2.4/src/ltable.c:387–394

static Node *getfreepos (Table *t) {
  while (t->lastfree > t->node) {
    t->lastfree--;
    if (ttisnil(gkey(t->lastfree)))
      return t->lastfree;
  }
  return NULL;  /* could not find a free place */
}