index() applied BM optimization to wrong argument

p4raw-id: //depot/perl@1779

1 files changed, 2 insertions, 0 deletions

diff --git a/op.c b/op.c
index 33a9efd693..53fb8c1ce3 100644
--- a/op.c
+++ b/op.c
@@ -4686,6 +4686,8 @@ ck_index(OP *o)
 {
     if (o->op_flags & OPf_KIDS) {
 	OP *kid = cLISTOPo->op_first->op_sibling;	/* get past pushmark */
+	if (kid)
+	    kid = kid->op_sibling;			/* get past "big" */
 	if (kid && kid->op_type == OP_CONST)
 	    fbm_compile(((SVOP*)kid)->op_sv, 0);
     }