fixed bug in channel.get() calls

src/deferredget.cpp

@@ -32,14 +32,17 @@ Deferred *DeferredGet::reportSuccess(uint32_t messageCount) const
  // we now know the name, so we can install the message callback on the channel
  _channel->install("", [channel, messageCallback, finalizeCallback](const Message &message, uint64_t deliveryTag, bool redelivered) {
 
- // we can remove the callback now from the channel
- channel->uninstall("");
- 
+ // install a monitor to deal with the case that the channel is removed
+ Monitor monitor(channel);
+
  // call the callbacks
  if (messageCallback) messageCallback(message, deliveryTag, redelivered);
 
  // call the finalize callback
  if (finalizeCallback) finalizeCallback();
+
+ // we can remove the callback now from the channel
+ if (monitor.valid()) channel->uninstall("");
  });
 
  // return next object