--- old/src/share/vm/memory/collectorPolicy.cpp	2013-03-19 10:34:08.000000000 -0400
+++ new/src/share/vm/memory/collectorPolicy.cpp	2013-03-19 10:34:08.000000000 -0400
@@ -539,7 +539,7 @@
     Generation *gen0 = gch->get_gen(0);
     assert(gen0->supports_inline_contig_alloc(),
       "Otherwise, must do alloc within heap lock");
-    if (gen0->should_allocate(size, is_tlab)) {
+    if (gen0 != NULL && gen0->should_allocate(size, is_tlab)) {
       result = gen0->par_allocate(size, is_tlab);
       if (result != NULL) {
         assert(gch->is_in_reserved(result), "result not in heap");
@@ -649,7 +649,7 @@
   HeapWord* result = NULL;
   for (int i = number_of_generations() - 1; i >= 0 && result == NULL; i--) {
     Generation *gen = gch->get_gen(i);
-    if (gen->should_allocate(size, is_tlab)) {
+    if (gen != NULL && gen->should_allocate(size, is_tlab)) {
       result = gen->expand_and_allocate(size, is_tlab);
     }
   }
@@ -821,7 +821,10 @@
 bool GenCollectorPolicy::should_try_older_generation_allocation(
         size_t word_size) const {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
-  size_t gen0_capacity = gch->get_gen(0)->capacity_before_gc();
+  Generation* gen = gch->get_gen(0);
+  guarantee(gen != NULL, "need generation");
+  
+  size_t gen0_capacity = gen->capacity_before_gc();
   return    (word_size > heap_word_size(gen0_capacity))
          || GC_locker::is_active_and_needs_gc()
          || gch->incremental_collection_failed();
--- old/src/share/vm/memory/genCollectedHeap.hpp	2013-03-19 10:34:10.000000000 -0400
+++ new/src/share/vm/memory/genCollectedHeap.hpp	2013-03-19 10:34:10.000000000 -0400
@@ -468,8 +468,9 @@
     // that it would not.
     assert(heap()->collector_policy()->is_two_generation_policy(),
            "the following definition may not be suitable for an n(>2)-generation system");
-    return incremental_collection_failed() ||
-           (consult_young && !get_gen(0)->collection_attempt_is_safe());
+    Generation *gen = get_gen(0);
+    return gen == NULL || incremental_collection_failed() ||
+           (consult_young && !gen->collection_attempt_is_safe());
   }
 
   // If a generation bails out of an incremental collection,