From 0a9bc09884ad3e0c481cf4d4c78d477620e552a6 Mon Sep 17 00:00:00 2001
From: Mark van Renswoude <mark@x2software.net>
Date: Tue, 14 Feb 2017 22:45:59 +0100
Subject: [PATCH] Fixed #11: Improve stack traces for exceptions Fixed #12:
 Stack overflow when an exception occurs in the middleware

---
 Tapeti/Connection/TapetiConsumer.cs | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/Tapeti/Connection/TapetiConsumer.cs b/Tapeti/Connection/TapetiConsumer.cs
index b3b3ed6..e3ede98 100644
--- a/Tapeti/Connection/TapetiConsumer.cs
+++ b/Tapeti/Connection/TapetiConsumer.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.ExceptionServices;
 using RabbitMQ.Client;
 using Tapeti.Config;
 using Tapeti.Helpers;
@@ -32,6 +33,7 @@ namespace Tapeti.Connection
         public override void HandleBasicDeliver(string consumerTag, ulong deliveryTag, bool redelivered, string exchange, string routingKey,
             IBasicProperties properties, byte[] body)
         {
+            ExceptionDispatchInfo exception = null;
             try
             {
                 var message = dependencyResolver.Resolve<IMessageSerializer>().Deserialize(body, properties);
@@ -81,19 +83,23 @@ namespace Tapeti.Connection
 
                         if (!validMessageType)
                             throw new ArgumentException($"Unsupported message type: {message.GetType().FullName}");
+
+                        worker.Respond(deliveryTag, ConsumeResponse.Ack);
                     }
                     catch (Exception e)
                     {
-                        worker.Respond(deliveryTag, exceptionStrategy.HandleException(context, UnwrapException(e)));
+                        exception = ExceptionDispatchInfo.Capture(UnwrapException(e));
+                        worker.Respond(deliveryTag, exceptionStrategy.HandleException(context, exception.SourceException));
                     }
                 }
-
-                worker.Respond(deliveryTag, ConsumeResponse.Ack);
             }
             catch (Exception e)
             {
-                worker.Respond(deliveryTag, exceptionStrategy.HandleException(null, UnwrapException(e)));
+                exception = ExceptionDispatchInfo.Capture(UnwrapException(e));
+                worker.Respond(deliveryTag, exceptionStrategy.HandleException(null, exception.SourceException));
             }
+
+            exception?.Throw();
         }
 
 
@@ -103,11 +109,14 @@ namespace Tapeti.Connection
             // code using Tasks we have to unwrap these ourselves to get the proper
             // exception directly instead of "Errors occured". We might lose
             // some stack traces in the process though.
-            var aggregateException = exception as AggregateException;
-            if (aggregateException != null && aggregateException.InnerExceptions.Count == 1)
-                throw aggregateException.InnerExceptions[0];
+            while (true)
+            {
+                var aggregateException = exception as AggregateException;
+                if (aggregateException == null || aggregateException.InnerExceptions.Count != 1)
+                    return exception;
 
-            return UnwrapException(exception);
+                exception = aggregateException.InnerExceptions[0];
+            }
         }