--- old/src/share/vm/gc/g1/g1ConcurrentMark.cpp	2017-03-08 10:51:31.253191120 +0100
+++ new/src/share/vm/gc/g1/g1ConcurrentMark.cpp	2017-03-08 10:51:31.139187743 +0100
@@ -2408,11 +2408,11 @@
   size_t n = 0;
   G1TaskQueueEntry task_entry;
   while (n < G1CMMarkStack::EntriesPerChunk && _task_queue->pop_local(task_entry)) {
-    buffer[n] = task_entry;
+    buffer[n].assign(task_entry);
     ++n;
   }
   if (n < G1CMMarkStack::EntriesPerChunk) {
-    buffer[n] = G1TaskQueueEntry();
+    buffer[n].assign(G1TaskQueueEntry());
   }
 
   if (n > 0) {