[corlib] Fix a edge case of ConcurrentQueue dequeuing by retrying after we fix up...

diff --git a/mcs/class/corlib/System.Collections.Concurrent/ConcurrentQueue.cs b/mcs/class/corlib/System.Collections.Concurrent/ConcurrentQueue.cs
index 381c6985ba3d51ea188aef78952e7bdcccad59cc..2c115e70cba08b15847a4f22e8b1ad3d1bfdc486 100644 (file)
--- a/mcs/class/corlib/System.Collections.Concurrent/ConcurrentQueue.cs
+++ b/mcs/class/corlib/System.Collections.Concurrent/ConcurrentQueue.cs
@@ -106,11 +106,12 @@ namespace System.Collections.Concurrent
                                
                                if (oldHead == head) {
                                        // Empty case ?
-                                       if (oldHead == oldTail) {       
+                                       if (oldHead == oldTail) {
                                                // This should be false then
                                                if (oldNext != null) {
                                                        // If not then the linked list is mal formed, update tail
                                                        Interlocked.CompareExchange (ref tail, oldNext, oldTail);
+                                                       continue;
                                                }
                                                result = default (T);
                                                return false;