Capture first connection attempt as inner exception in BrokerUnreachableException

Author: Emile Joubert

projects/client/RabbitMQ.Client/src/client/api/ConnectionFactory.cs

@@ -313,7 +313,8 @@ public virtual IConnection CreateConnection(int maxRedirects)
             if (conn != null) {
                 return conn;
             }
-            throw new BrokerUnreachableException(connectionAttempts, connectionErrors);
+            Exception Inner = connectionErrors[Endpoint] as Exception;
+            throw new BrokerUnreachableException(connectionAttempts, connectionErrors, Inner);
         }
 
         ///<summary>Create a connection to the specified endpoint

projects/client/RabbitMQ.Client/src/client/exceptions/BrokerUnreachableException.cs

@@ -74,10 +74,12 @@ public class BrokerUnreachableException: IOException
 
         ///<summary>Construct a BrokerUnreachableException. Expects
         ///maps as per the description of the ConnectionAttempts and
-        ///ConnectionErrors properties.</summary>
+        ///ConnectionErrors properties. The inner exception is associated
+        ///with only one connection attempt.</summary>
         public BrokerUnreachableException(IDictionary connectionAttempts,
-                                          IDictionary connectionErrors)
-            : base("None of the specified endpoints were reachable")
+                                          IDictionary connectionErrors,
+                                          Exception Inner)
+            : base("None of the specified endpoints were reachable", Inner)
         {
             m_connectionAttempts = connectionAttempts;
             m_connectionErrors = connectionErrors;