Index: lib/IR/BasicBlock.cpp
===================================================================
--- lib/IR/BasicBlock.cpp
+++ lib/IR/BasicBlock.cpp
@@ -399,8 +399,8 @@
     // incoming values...
     BasicBlock *Successor = *I;
     PHINode *PN;
-    for (BasicBlock::iterator II = Successor->begin();
-         (PN = dyn_cast<PHINode>(II)); ++II) {
+    for (BasicBlock::iterator II = Successor->begin(), E = Successor->end();
+         II != E && (PN = dyn_cast<PHINode>(II)); ++II) {
       int IDX = PN->getBasicBlockIndex(this);
       while (IDX != -1) {
         PN->setIncomingBlock((unsigned)IDX, New);