rem: return 0;
add: return NULL;
context: lookup_zone (parser_control const *pc, char const *name){  table const *tp;  /* Try local zone abbreviations first; they're more likely to be right.  */  for (tp = pc->local_time_zone_table; tp->name; tp++)    if (strcmp (name, tp->name) == 0)      return tp;  for (tp = time_zone_table; tp->name; tp++)    if (strcmp (name, tp->name) == 0)      return tp;  return 0;}