From f47ee9f26e76d69459ce6f1db367da63ff7ac6c9 Mon Sep 17 00:00:00 2001
From: Richard Stallman <rms@gnu.org>
Date: Sat, 29 Aug 1992 03:11:59 +0000
Subject: [PATCH] (chainon): Check for op2 being the last elt of the chain.

From-SVN: r1987
---
 gcc/tree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/tree.c b/gcc/tree.c
index c22f3b8aa05..8f03250b6a7 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -1490,6 +1490,7 @@ chainon (op1, op2)
     {
       for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
 	if (t == op2) abort ();	/* Circularity being created */
+      if (t == op2) abort ();	/* Circularity being created */
       TREE_CHAIN (t) = op2;
       return op1;
     }
-- 
2.30.2