CSHARP-654: fixed bug for when network reliability causes us to miss a reconnection by one of the members.

Author: craiggwilson

MongoDB.Driver/Communication/Proxies/MultipleInstanceMongoServerProxy.cs

@@ -345,7 +345,6 @@ protected void EnsureInstanceWithAddress(MongoServerAddress address)
                     AddInstance(instance);
                     if (_state != MongoServerState.Disconnecting && _state != MongoServerState.Disconnected)
                     {
-                        _state = MongoServerState.Connecting;
                         ConnectInstance(instance);
                     }
                 }

MongoDB.Driver/Communication/Proxies/ReplicaSetMongoServerProxy.cs

@@ -126,40 +126,32 @@ protected override MongoServerState DetermineServerState(MongoServerState curren
 
             // the order of the tests is significant
             // and resolves ambiguities when more than one state might match
-            if (currentState == MongoServerState.Disconnecting)
+            if (currentState == MongoServerState.Disconnected)
+            {
+                return MongoServerState.Disconnected;
+            }
+            else if (currentState == MongoServerState.Disconnecting)
             {
                 if (instances.All(i => i.State == MongoServerState.Disconnected))
                 {
                     return MongoServerState.Disconnected;
                 }
+
+                return MongoServerState.Disconnecting;
             }
             else
             {
-                if (instances.All(i => i.State == MongoServerState.Disconnected))
-                {
-                    return MongoServerState.Disconnected;
-                }
-                else if (instances.All(i => i.State == MongoServerState.Connected))
+                if (instances.All(i => i.State == MongoServerState.Connected))
                 {
                     return MongoServerState.Connected;
                 }
-                else if (instances.Any(i => i.State == MongoServerState.Connecting))
-                {
-                    return MongoServerState.Connecting;
-                }
-                else if (instances.Any(i => i.State == MongoServerState.Unknown))
-                {
-                    return MongoServerState.Unknown;
-                }
                 else if (instances.Any(i => i.State == MongoServerState.Connected))
                 {
                     return MongoServerState.ConnectedToSubset;
                 }
 
-                throw new MongoInternalException("Unexpected server instance states.");
+                return MongoServerState.Connecting;
             }
-
-            return currentState;
         }
 
         /// <summary>

MongoDB.Driver/Communication/Proxies/ShardedMongoServerProxy.cs

@@ -95,36 +95,28 @@ protected override MongoServerState DetermineServerState(MongoServerState curren
 
             // the order of the tests is significant
             // and resolves ambiguities when more than one state might match
-            if (currentState == MongoServerState.Disconnecting)
+            if (currentState == MongoServerState.Disconnected)
+            {
+                return MongoServerState.Disconnected;
+            }
+            else if (currentState == MongoServerState.Disconnecting)
             {
                 if (instances.All(i => i.State == MongoServerState.Disconnected))
                 {
                     return MongoServerState.Disconnected;
                 }
+
+                return MongoServerState.Disconnecting;
             }
             else
             {
                 if (instances.Any(i => i.State == MongoServerState.Connected))
                 {
                     return MongoServerState.Connected;
                 }
-                else if (instances.All(i => i.State == MongoServerState.Disconnected))
-                {
-                    return MongoServerState.Disconnected;
-                }
-                else if (instances.All(i => i.State == MongoServerState.Connecting))
-                {
-                    return MongoServerState.Connecting;
-                }
-                else if (instances.Any(i => i.State == MongoServerState.Unknown))
-                {
-                    return MongoServerState.Unknown;
-                }
 
-                throw new MongoInternalException("Unexpected server instance states.");
+                return MongoServerState.Connecting;
             }
-
-            return currentState;
         }
 
         /// <summary>