(chainon): Check for op2 being the last elt of the chain.

From-SVN: r1987

1 files changed, 1 insertions, 0 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index c22f3b8a..8f03250 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;
     }