1 files changed, 14 insertions, 7 deletions

diff --git a/cpp/src/qpid/ha/ReplicatingSubscription.cpp b/cpp/src/qpid/ha/ReplicatingSubscription.cpp
index 7438c95bc2..ebc2365664 100644
--- a/cpp/src/qpid/ha/ReplicatingSubscription.cpp
+++ b/cpp/src/qpid/ha/ReplicatingSubscription.cpp
@@ -233,7 +233,10 @@ ReplicatingSubscription::ReplicatingSubscription(
 
         // Set the guard
         if (Primary::get()) guard = Primary::get()->getGuard(queue, getBrokerInfo());
-        if (!guard) guard.reset(new QueueGuard(*queue, getBrokerInfo()));
+        if (!guard) {
+            QPID_LOG(debug, logPrefix << "No pre-set guard found, creating one.");
+            guard.reset(new QueueGuard(*queue, getBrokerInfo()));
+        }
         guard->attach(*this);
 
         // Guard is active, dequeued can be called concurrently.
@@ -332,9 +335,12 @@ void ReplicatingSubscription::cancel()
 }
 
 // Consumer override, called on primary in the backup's IO thread.
-void ReplicatingSubscription::acknowledged(const QueuedMessage& msg) {
-    // Finish completion of message, it has been acknowledged by the backup.
-    guard->complete(msg);
+void ReplicatingSubscription::acknowledged(const QueuedMessage& qm) {
+    if (qm.queue == getQueue().get()) { // Don't complete messages on the internal queue
+        // Finish completion of message, it has been acknowledged by the backup.
+        QPID_LOG(trace, logPrefix << "Acknowledged " << qm);
+        guard->complete(qm);
+    }
 }
 
 // Hide the "queue deleted" error for a ReplicatingSubscription when a
@@ -363,15 +369,16 @@ void ReplicatingSubscription::sendDequeueEvent(Mutex::ScopedLock&)
 // arbitrary connection threads.
 void ReplicatingSubscription::dequeued(const QueuedMessage& qm)
 {
+    assert (qm.queue == getQueue().get());
     bool doComplete = false;
-    QPID_LOG(trace, logPrefix << "Dequeued " << qm);
     {
         Mutex::ScopedLock l(lock);
+        assert(!dequeues.contains(qm.position));
         dequeues.add(qm.position);
+        // If we have not yet sent this message to the backup, then
+        // complete it now as it will never be accepted.
         if (qm.position > position) doComplete = true;
     }
-    // If we have not yet sent this message to the backup, then
-    // complete it now as it will never be accepted.
     if (doComplete) guard->complete(qm);
     notify();                   // Ensure a call to doDispatch
 }