2 files changed, 149 insertions, 34 deletions

diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
index 01b1668..34f0924 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
@@ -148,6 +148,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
         protected virtual void OnNewClient(IClientAPI client)
         {
+            client.OnTeleportCancel += OnClientCancelTeleport;
             client.OnTeleportHomeRequest += TeleportHome;
             client.OnTeleportLandmarkRequest += RequestTeleportLandmark;
         }
@@ -168,6 +169,14 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
         #region Agent Teleports
 
+        private void OnClientCancelTeleport(IClientAPI client)
+        {
+            m_entityTransferStateMachine.UpdateInTransit(client.AgentId, AgentTransferState.Cancelling);
+
+            m_log.DebugFormat(
+                "[ENTITY TRANSFER MODULE]: Received teleport cancel request from {0} in {1}", client.Name, Scene.Name);
+        }
+
         public void Teleport(ScenePresence sp, ulong regionHandle, Vector3 position, Vector3 lookAt, uint teleportFlags)
         {
             if (sp.Scene.Permissions.IsGridGod(sp.UUID))
@@ -567,6 +576,15 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 return;
             }
 
+            if (m_entityTransferStateMachine.GetAgentTransferState(sp.UUID) == AgentTransferState.Cancelling)
+            {
+                m_log.DebugFormat(
+                    "[ENTITY TRANSFER MODULE]: Cancelled teleport of {0} to {1} from {2} after CreateAgent on client request", 
+                    sp.Name, finalDestination.RegionName, sp.Scene.Name);
+
+                return;
+            }
+
             // Past this point we have to attempt clean up if the teleport fails, so update transfer state.
             m_entityTransferStateMachine.UpdateInTransit(sp.UUID, AgentTransferState.Transferring);
 
@@ -631,7 +649,16 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 return;
             }
 
-            sp.ControllingClient.SendTeleportProgress(teleportFlags | (uint)TeleportFlags.DisableCancel, "sending_dest");
+            if (m_entityTransferStateMachine.GetAgentTransferState(sp.UUID) == AgentTransferState.Cancelling)
+            {
+                m_log.DebugFormat(
+                    "[ENTITY TRANSFER MODULE]: Cancelled teleport of {0} to {1} from {2} after UpdateAgent on client request", 
+                    sp.Name, finalDestination.RegionName, sp.Scene.Name);
+
+                CleanupAbortedInterRegionTeleport(sp, finalDestination);
+
+                return;
+            }
 
             m_log.DebugFormat(
                 "[ENTITY TRANSFER MODULE]: Sending new CAPS seed url {0} from {1} to {2}",
@@ -714,14 +741,19 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 //            }
         }
 
-        protected virtual void Fail(ScenePresence sp, GridRegion finalDestination, bool logout)
+        /// <summary>
+        /// Clean up an inter-region teleport that did not complete, either because of simulator failure or cancellation.
+        /// </summary>
+        /// <remarks>
+        /// All operations here must be idempotent so that we can call this method at any point in the teleport process
+        /// up until we send the TeleportFinish event quene event to the viewer.
+        /// <remarks>
+        /// <param name='sp'> </param>
+        /// <param name='finalDestination'></param>
+        protected virtual void CleanupAbortedInterRegionTeleport(ScenePresence sp, GridRegion finalDestination)
         {
             m_entityTransferStateMachine.UpdateInTransit(sp.UUID, AgentTransferState.CleaningUp);
 
-            // Client never contacted destination. Let's restore everything back
-            sp.ControllingClient.SendTeleportFailed("Problems connecting to destination.");
-
-            // Fail. Reset it back
             sp.IsChildAgent = false;
             ReInstantiateScripts(sp);
 
@@ -729,7 +761,20 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
             // Finally, kill the agent we just created at the destination.
             Scene.SimulationService.CloseAgent(finalDestination, sp.UUID);
+        }
+
+        /// <summary>
+        /// Signal that the inter-region teleport failed and perform cleanup.
+        /// </summary>
+        /// <param name='sp'></param>
+        /// <param name='finalDestination'></param>
+        /// <param name='logout'></param>
+        protected virtual void Fail(ScenePresence sp, GridRegion finalDestination, bool logout)
+        {
+            CleanupAbortedInterRegionTeleport(sp, finalDestination);
 
+            sp.ControllingClient.SendTeleportFailed(
+                string.Format("Problems connecting to destination {0}", finalDestination.RegionName));
             sp.Scene.EventManager.TriggerTeleportFail(sp.ControllingClient, logout);
         }
 
@@ -2097,7 +2142,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
         public bool IsInTransit(UUID id)
         {
-            return m_entityTransferStateMachine.IsInTransit(id);
+            return m_entityTransferStateMachine.GetAgentTransferState(id) != null;
         }
 
         protected void ReInstantiateScripts(ScenePresence sp)
diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferStateMachine.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferStateMachine.cs
index d0cab49..24d81d9 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferStateMachine.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferStateMachine.cs
@@ -51,8 +51,9 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
     /// This is a state machine.
     ///
     /// [Entry]               => Preparing
-    /// Preparing             => { Transferring || CleaningUp || [Exit] }
-    /// Transferring          => { ReceivedAtDestination || CleaningUp }
+    /// Preparing             => { Transferring || Cancelling || CleaningUp || [Exit] }
+    /// Transferring          => { ReceivedAtDestination || Cancelling || CleaningUp }
+    /// Cancelling            => CleaningUp
     /// ReceivedAtDestination => CleaningUp
     /// CleaningUp            => [Exit]
     ///
@@ -64,7 +65,8 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         Preparing,              // The agent is being prepared for transfer
         Transferring,           // The agent is in the process of being transferred to a destination
         ReceivedAtDestination,  // The destination has notified us that the agent has been successfully received
-        CleaningUp              // The agent is being changed to child/removed after a transfer
+        CleaningUp,             // The agent is being changed to child/removed after a transfer
+        Cancelling              // The user has cancelled the teleport but we have yet to act upon this.
     }
 
     /// <summary>
@@ -115,42 +117,110 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         /// <param name='newState'></param>
         /// <returns></returns>
         /// <exception cref='Exception'>Illegal transitions will throw an Exception</exception>
-        internal void UpdateInTransit(UUID id, AgentTransferState newState)
+        internal bool UpdateInTransit(UUID id, AgentTransferState newState)
         {
+            bool transitionOkay = false;
+
+            // We don't want to throw an exception on cancel since this can come it at any time.
+            bool failIfNotOkay = true;
+
+            // Should be a failure message if failure is not okay.
+            string failureMessage = null;
+
+            AgentTransferState? oldState = null;
+
             lock (m_agentsInTransit)
             {
                 // Illegal to try and update an agent that's not actually in transit.
                 if (!m_agentsInTransit.ContainsKey(id))
-                    throw new Exception(
-                        string.Format(
-                            "Agent with ID {0} is not registered as in transit in {1}",
-                            id, m_mod.Scene.RegionInfo.RegionName));
-
-                AgentTransferState oldState = m_agentsInTransit[id];
+                {
+                    if (newState != AgentTransferState.Cancelling)
+                        failureMessage = string.Format(
+                                "Agent with ID {0} is not registered as in transit in {1}",
+                                id, m_mod.Scene.RegionInfo.RegionName);
+                    else
+                        failIfNotOkay = false;
+                }
+                else
+                {
+                    oldState = m_agentsInTransit[id];
 
-                bool transitionOkay = false;
+                    if (newState == AgentTransferState.CleaningUp && oldState != AgentTransferState.CleaningUp)
+                    {
+                        transitionOkay = true;
+                    }
+                    else if (newState == AgentTransferState.Transferring && oldState == AgentTransferState.Preparing)
+                    {
+                        transitionOkay = true;
+                    }
+                    else if (newState == AgentTransferState.ReceivedAtDestination && oldState == AgentTransferState.Transferring)
+                    {
+                        transitionOkay = true;
+                    }
+                    else
+                    {
+                        if (newState == AgentTransferState.Cancelling 
+                            && (oldState == AgentTransferState.Preparing || oldState == AgentTransferState.Transferring))
+                        {
+                            transitionOkay = true;
+                        }
+                        else
+                        {
+                            failIfNotOkay = false;
+                        }
+                    }
 
-                if (newState == AgentTransferState.CleaningUp && oldState != AgentTransferState.CleaningUp)
-                    transitionOkay = true;
-                else if (newState == AgentTransferState.Transferring && oldState == AgentTransferState.Preparing)
-                    transitionOkay = true;
-                else if (newState == AgentTransferState.ReceivedAtDestination && oldState == AgentTransferState.Transferring)
-                    transitionOkay = true;
+                    if (!transitionOkay)
+                        failureMessage 
+                            = string.Format(
+                                "Agent with ID {0} is not allowed to move from old transit state {1} to new state {2} in {3}",
+                                id, oldState, newState, m_mod.Scene.RegionInfo.RegionName);
+                }
 
                 if (transitionOkay)
+                {
                     m_agentsInTransit[id] = newState;
-                else
-                    throw new Exception(
-                        string.Format(
-                            "Agent with ID {0} is not allowed to move from old transit state {1} to new state {2} in {3}",
-                            id, oldState, newState, m_mod.Scene.RegionInfo.RegionName));
+
+//                    m_log.DebugFormat(
+//                        "[ENTITY TRANSFER STATE MACHINE]: Changed agent with id {0} from state {1} to {2} in {3}", 
+//                        id, oldState, newState, m_mod.Scene.Name);
+                }
+                else if (failIfNotOkay)
+                {
+                    throw new Exception(failureMessage);
+                }
+//                else
+//                {
+//                    if (oldState != null)
+//                        m_log.DebugFormat(
+//                            "[ENTITY TRANSFER STATE MACHINE]: Ignored change of agent with id {0} from state {1} to {2} in {3}", 
+//                            id, oldState, newState, m_mod.Scene.Name);
+//                    else
+//                        m_log.DebugFormat(
+//                            "[ENTITY TRANSFER STATE MACHINE]: Ignored change of agent with id {0} to state {1} in {2} since agent not in transit", 
+//                            id, newState, m_mod.Scene.Name);
+//                }
             }
+
+            return transitionOkay;
         }
 
-        internal bool IsInTransit(UUID id)
+        /// <summary>
+        /// Gets the current agent transfer state.
+        /// </summary>
+        /// <returns>Null if the agent is not in transit</returns>
+        /// <param name='id'>
+        /// Identifier.
+        /// </param>
+        internal AgentTransferState? GetAgentTransferState(UUID id)
         {
             lock (m_agentsInTransit)
-                return m_agentsInTransit.ContainsKey(id);
+            {
+                if (!m_agentsInTransit.ContainsKey(id))
+                    return null;
+                else
+                    return m_agentsInTransit[id];
+            }
         }
 
         /// <summary>
@@ -203,14 +273,14 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             
             lock (m_agentsInTransit)
             {
-                if (!IsInTransit(id))
+                AgentTransferState? currentState = GetAgentTransferState(id);
+
+                if (currentState == null)
                     throw new Exception(
                         string.Format(
                             "Asked to wait for destination callback for agent with ID {0} in {1} but agent is not in transit",
                             id, m_mod.Scene.RegionInfo.RegionName));
 
-                AgentTransferState currentState = m_agentsInTransit[id];
-
                 if (currentState != AgentTransferState.Transferring && currentState != AgentTransferState.ReceivedAtDestination)
                     throw new Exception(
                         string.Format(