Handle blit_back_with_light with empty area

fixes #13306

src/voxelalgorithms.cpp

@@ -1028,6 +1028,9 @@ void blit_back_with_light(Map *map, MMVManip *vm,
 	std::map<v3s16, MapBlock*> *modified_blocks)
 {
 	const NodeDefManager *ndef = map->getNodeDefManager();
+
+	if (vm->m_area.hasEmptyExtent())
+		return;
 	mapblock_v3 minblock = getNodeBlockPos(vm->m_area.MinEdge);
 	mapblock_v3 maxblock = getNodeBlockPos(vm->m_area.MaxEdge);
 	// First queue is for day light, second is for night light.