--- old/src/share/vm/gc/g1/g1CollectedHeap.cpp	2015-08-13 12:06:31.371957148 -0400
+++ new/src/share/vm/gc/g1/g1CollectedHeap.cpp	2015-08-13 12:06:30.771922866 -0400
@@ -1185,7 +1185,7 @@
       } else {
         curr_region = NULL;
       }
-      _hrm.shrink_at(curr_index);
+      _hrm.shrink_at(curr_index, 1);
       uncommitted_regions++;
     }
 
--- old/src/share/vm/gc/g1/heapRegionManager.cpp	2015-08-13 12:06:34.492135417 -0400
+++ new/src/share/vm/gc/g1/heapRegionManager.cpp	2015-08-13 12:06:33.896101363 -0400
@@ -426,7 +426,7 @@
       (num_last_found = find_empty_from_idx_reverse(cur, &idx_last_found)) > 0) {
     uint to_remove = MIN2(num_regions_to_remove - removed, num_last_found);
 
-    uncommit_regions(idx_last_found + num_last_found - to_remove, to_remove);
+    shrink_at(idx_last_found + num_last_found - to_remove, to_remove);
 
     cur -= num_last_found;
     removed += to_remove;
@@ -437,11 +437,15 @@
   return removed;
 }
 
-void HeapRegionManager::shrink_at(uint index) {
-  assert(is_available(index), err_msg("Expected available region at index %u", index));
-  HeapRegion* curr_region  = _regions.get_by_index(index);
-  assert(curr_region->is_free(), err_msg("Expected free region at index %u", index));
-  uncommit_regions(index, 1);
+void HeapRegionManager::shrink_at(uint index, size_t num_regions) {
+#ifdef ASSERT
+  for (uint i = index; i < (index + num_regions); i++) {
+    assert(is_available(i), err_msg("Expected available region at index %u", i));
+    assert(at(i)->is_empty(), err_msg("Expected empty region at index %u", i));
+    assert(at(i)->is_free(), err_msg("Expected free region at index %u", i));
+  }
+#endif
+  uncommit_regions(index, num_regions);
 }
 
 uint HeapRegionManager::find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const {
--- old/src/share/vm/gc/g1/heapRegionManager.hpp	2015-08-13 12:06:37.616313913 -0400
+++ new/src/share/vm/gc/g1/heapRegionManager.hpp	2015-08-13 12:06:37.016279631 -0400
@@ -241,8 +241,9 @@
   // Return the actual number of uncommitted regions.
   uint shrink_by(uint num_regions_to_remove);
 
-  // Uncommit the region at the specified index, which must be available and free.
-  void shrink_at(uint index);
+  // Uncommit a number of regions starting at the specified index, which must be available,
+  // empty, and free.
+  void shrink_at(uint index, size_t num_regions);
 
   void verify();