Can't close channel from consumer dispatcher

See #1567

Author: lukebakken

projects/Test/Integration/TestAsyncConsumer.cs

@@ -603,6 +603,38 @@ public async Task TestDeclarationOfManyAutoDeleteQueuesWithTransientConsumer()
             AssertRecordedQueues((RabbitMQ.Client.Framing.Impl.AutorecoveringConnection)_conn, 0);
         }
 
+        [Fact]
+        public async Task TestCloseWithinEventHandler_GH1567()
+        {
+            var tcs = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
+
+            QueueDeclareOk q = await _channel.QueueDeclareAsync();
+            string queueName = q.QueueName;
+
+            var consumer = new AsyncEventingBasicConsumer(_channel);
+            consumer.Received += async (_, eventArgs) =>
+            {
+                await _channel.BasicCancelAsync(eventArgs.ConsumerTag);
+                // await _channel.CloseAsync();
+                // _channel.Dispose();
+                // _channel = null;
+                tcs.TrySetResult(true);
+            };
+
+            await _channel.BasicConsumeAsync(consumer, queueName, true);
+
+            var bp = new BasicProperties();
+
+            await _channel.BasicPublishAsync(exchange: string.Empty, routingKey: queueName,
+                basicProperties: bp, mandatory: true, body: GetRandomBody(64));
+
+            Assert.True(await tcs.Task);
+
+            await _channel.CloseAsync();
+            _channel.Dispose();
+            _channel = null;
+        }
+
         private static void SetException(Exception ex, params TaskCompletionSource<bool>[] tcsAry)
         {
             foreach (TaskCompletionSource<bool> tcs in tcsAry)