fix segfault

qic.c

@@ -3712,6 +3712,7 @@ void compile_node(buffer_t *gbuf, buffer_t *buf, list_t *ctx, table_t *ltab, sta
       }
 
       node->a->b = nodeb(bbuf);
+      node->a->t2 = NULL;
 
       compile_node(gbuf, tbuf, ctx, ltab, lstk, sstk, lbl, node->a);