--- old/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	2015-01-27 17:28:12.918323936 -0500
+++ new/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	2015-01-27 17:28:12.634307515 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -762,8 +762,11 @@
 void CompactibleFreeListSpace::blk_iterate_careful(BlkClosureCareful* cl) {
   assert_lock_strong(freelistLock());
   HeapWord *cur, *limit;
-  for (cur = bottom(), limit = end(); cur < limit;
-       cur += cl->do_blk_careful(cur));
+  size_t res;
+  for (cur = bottom(), limit = end(); cur < limit; cur += res) {
+    res = cl->do_blk_careful(cur);
+    assert(cur + res > cur, "Not monotonically increasing ?");
+  }
 }
 
 // Apply the given closure to each block in the space.