Merge branch 'master' into careminster

Conflicts:
	OpenSim/Region/Application/OpenSimBase.cs
	OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
	OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
	OpenSim/Region/Framework/Scenes/Scene.cs
	OpenSim/Region/Framework/Scenes/ScenePresence.cs

16 files changed, 499 insertions, 210 deletions

diff --git a/OpenSim/Region/Application/Application.cs b/OpenSim/Region/Application/Application.cs
index 2e155ec..3a4e5df 100644
--- a/OpenSim/Region/Application/Application.cs
+++ b/OpenSim/Region/Application/Application.cs
@@ -142,19 +142,19 @@ namespace OpenSim
                         if (iocpThreads < iocpThreadsMin)
             {
                 iocpThreads = iocpThreadsMin;
-                m_log.InfoFormat("[OPENSIM MAIN]: Bumping up max IO completion threads to {0}",iocpThreads);
+                m_log.InfoFormat("[OPENSIM MAIN]: Bumping up max IOCP threads to {0}",iocpThreads);
             }
                         // Make sure we don't overallocate IOCP threads and thrash system resources
             if ( iocpThreads > iocpThreadsMax )
             {
                 iocpThreads = iocpThreadsMax;
-                m_log.InfoFormat("[OPENSIM MAIN]: Limiting max IO completion threads to {0}",iocpThreads);
+                m_log.InfoFormat("[OPENSIM MAIN]: Limiting max IOCP completion threads to {0}",iocpThreads);
             }
                         // set the resulting worker and IO completion thread counts back to ThreadPool
             if ( System.Threading.ThreadPool.SetMaxThreads(workerThreads, iocpThreads) )
                         {
                     m_log.InfoFormat(
-                    "[OPENSIM MAIN]: Threadpool set to {0} max worker threads and {1} max IO completion threads",
+                    "[OPENSIM MAIN]: Threadpool set to {0} max worker threads and {1} max IOCP threads",
                     workerThreads, iocpThreads);
                         }
                         else
diff --git a/OpenSim/Region/Application/OpenSim.cs b/OpenSim/Region/Application/OpenSim.cs
index 6dd1f5b..a18a6fe 100644
--- a/OpenSim/Region/Application/OpenSim.cs
+++ b/OpenSim/Region/Application/OpenSim.cs
@@ -172,6 +172,13 @@ namespace OpenSim
             if (userStatsURI != String.Empty)
                 MainServer.Instance.AddStreamHandler(new OpenSim.UXSimStatusHandler(this));
 
+            if (managedStatsURI != String.Empty)
+            {
+                string urlBase = String.Format("/{0}/", managedStatsURI);
+                MainServer.Instance.AddHTTPHandler(urlBase, StatsManager.HandleStatsRequest);
+                m_log.InfoFormat("[OPENSIM] Enabling remote managed stats fetch. URL = {0}", urlBase);
+            }
+
             if (m_console is RemoteConsole)
             {
                 if (m_consolePort == 0)
@@ -348,18 +355,6 @@ namespace OpenSim
             m_console.Commands.AddCommand("Regions", false, "delete-region",
                                           "delete-region <name>",
                                           "Delete a region from disk", RunCommand);
-
-            m_console.Commands.AddCommand("General", false, "modules list",
-                                          "modules list",
-                                          "List modules", HandleModules);
-
-            m_console.Commands.AddCommand("General", false, "modules load",
-                                          "modules load <name>",
-                                          "Load a module", HandleModules);
-
-            m_console.Commands.AddCommand("General", false, "modules unload",
-                                          "modules unload <name>",
-                                          "Unload a module", HandleModules);
         }
 
         protected override void ShutdownSpecific()
@@ -557,34 +552,6 @@ namespace OpenSim
         }
 
         /// <summary>
-        /// Load, Unload, and list Region modules in use
-        /// </summary>
-        /// <param name="module"></param>
-        /// <param name="cmd"></param>
-        private void HandleModules(string module, string[] cmd)
-        {
-            List<string> args = new List<string>(cmd);
-            args.RemoveAt(0);
-            string[] cmdparams = args.ToArray();
-
-            if (cmdparams.Length > 0)
-            {
-                switch (cmdparams[0].ToLower())
-                {
-                    case "list":
-                        //TODO: Convert to new region modules
-                        break;
-                    case "unload":
-                        //TODO: Convert to new region modules
-                        break;
-                    case "load":
-                        //TODO: Convert to new region modules
-                        break;
-                }
-            }
-        }
-
-        /// <summary>
         /// Runs commands issued by the server console from the operator
         /// </summary>
         /// <param name="command">The first argument of the parameter (the command)</param>
diff --git a/OpenSim/Region/Application/OpenSimBase.cs b/OpenSim/Region/Application/OpenSimBase.cs
index db76529..0f3bac4 100644
--- a/OpenSim/Region/Application/OpenSimBase.cs
+++ b/OpenSim/Region/Application/OpenSimBase.cs
@@ -75,6 +75,7 @@ namespace OpenSim
         protected int proxyOffset = 0;
         
         public string userStatsURI = String.Empty;
+        public string managedStatsURI = String.Empty;
 
         protected bool m_autoCreateClientStack = true;
 
@@ -197,6 +198,8 @@ namespace OpenSim
 
                 string permissionModules = startupConfig.GetString("permissionmodules", "DefaultPermissionsModule");
                 m_permsModules = new List<string>(permissionModules.Split(','));
+
+                managedStatsURI = startupConfig.GetString("ManagedStatsRemoteFetchURI", String.Empty);
             }
 
             // Load the simulation data service
diff --git a/OpenSim/Region/ClientStack/Linden/Caps/EventQueue/Tests/EventQueueTests.cs b/OpenSim/Region/ClientStack/Linden/Caps/EventQueue/Tests/EventQueueTests.cs
index 141af8a..626932f 100644
--- a/OpenSim/Region/ClientStack/Linden/Caps/EventQueue/Tests/EventQueueTests.cs
+++ b/OpenSim/Region/ClientStack/Linden/Caps/EventQueue/Tests/EventQueueTests.cs
@@ -91,7 +91,7 @@ namespace OpenSim.Region.ClientStack.Linden.Tests
         public void RemoveForClient()
         {
             TestHelpers.InMethod();
-//            log4net.Config.XmlConfigurator.Configure();
+//            TestHelpers.EnableLogging();
 
             UUID spId = TestHelpers.ParseTail(0x1);
 
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
index 0e20e38..8cbbfd9 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs
@@ -337,6 +337,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         private bool m_VelocityInterpolate = false;
         private const uint MaxTransferBytesPerPacket = 600;
 
+        private volatile bool m_justEditedTerrain = false;
 
         /// <value>
         /// List used in construction of data blocks for an object update packet.  This is to stop us having to
@@ -536,7 +537,13 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                 // We still perform a force close inside the sync lock since this is intended to attempt close where
                 // there is some unidentified connection problem, not where we have issues due to deadlock
                 if (!IsActive && !force)
+                {
+                    m_log.DebugFormat(
+                        "[CLIENT]: Not attempting to close inactive client {0} in {1} since force flag is not set", 
+                        Name, m_scene.Name);
+
                     return;
+                }
 
                 IsActive = false;
                 CloseWithoutChecks(sendStop);
@@ -1231,9 +1238,32 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                     LLHeightFieldMoronize(map);
 
                 LayerDataPacket layerpack = TerrainCompressor.CreateLandPacket(heightmap, patches);
-                layerpack.Header.Reliable = true;
+                
+                // When a user edits the terrain, so much data is sent, the data queues up fast and presents a sub optimal editing experience.  
+                // To alleviate this issue, when the user edits the terrain, we start skipping the queues until they're done editing the terrain.
+                // We also make them unreliable because it's extremely likely that multiple packets will be sent for a terrain patch area 
+                // invalidating previous packets for that area.
+
+                // It's possible for an editing user to flood themselves with edited packets but the majority of use cases are such that only a 
+                // tiny percentage of users will be editing the terrain.     Other, non-editing users will see the edits much slower.
+                
+                // One last note on this topic, by the time users are going to be editing the terrain, it's extremely likely that the sim will 
+                // have rezzed already and therefore this is not likely going to cause any additional issues with lost packets, objects or terrain 
+                // patches.
 
-                OutPacket(layerpack, ThrottleOutPacketType.Task);
+                // m_justEditedTerrain is volatile, so test once and duplicate two affected statements so we only have one cache miss.
+                if (m_justEditedTerrain)
+                {
+                    layerpack.Header.Reliable = false;
+                    OutPacket(layerpack,
+                               ThrottleOutPacketType.Unknown );
+                }
+                else
+                {
+                    layerpack.Header.Reliable = true;
+                    OutPacket(layerpack,
+                               ThrottleOutPacketType.Task);
+                }
             }
             catch (Exception e)
             {
@@ -6367,6 +6397,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             //m_log.Info("[LAND]: LAND:" + modify.ToString());
             if (modify.ParcelData.Length > 0)
             {
+                // Note: the ModifyTerrain event handler sends out updated packets before the end of this event.  Therefore, 
+                // a simple boolean value should work and perhaps queue up just a few terrain patch packets at the end of the edit.
+                m_justEditedTerrain = true; // Prevent terrain packet (Land layer) from being queued, make it unreliable
                 if (OnModifyTerrain != null)
                 {
                     for (int i = 0; i < modify.ParcelData.Length; i++)
@@ -6382,6 +6415,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                         }
                     }
                 }
+                m_justEditedTerrain = false; // Queue terrain packet (Land layer) if necessary, make it reliable again
             }
 
             return true;
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
index 71b464b..0431b53 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs
@@ -1871,9 +1871,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
     
                 if (!client.SceneAgent.IsChildAgent)
                      client.Kick("Simulator logged you out due to connection timeout.");
-    
-                client.CloseWithoutChecks(true);
             }
+
+            m_scene.IncomingCloseAgent(client.AgentId, true);
         }
 
         private void IncomingPacketHandler()
@@ -2216,7 +2216,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             if (!client.IsLoggingOut)
             {
                 client.IsLoggingOut = true;
-                client.Close(false, false);
+                m_scene.IncomingCloseAgent(client.AgentId, false);
             }
         }
     }
diff --git a/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs b/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs
index b47ff54..9700224 100644
--- a/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs
+++ b/OpenSim/Region/ClientStack/Linden/UDP/Tests/BasicCircuitTests.cs
@@ -200,7 +200,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP.Tests
         public void TestLogoutClientDueToAck()
         {
             TestHelpers.InMethod();
-//            TestHelpers.EnableLogging();
+            TestHelpers.EnableLogging();
 
             IniConfigSource ics = new IniConfigSource();
             IConfig config = ics.AddConfig("ClientStack.LindenUDP");
diff --git a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
index 4286eef..711167f 100644
--- a/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
+++ b/OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs
@@ -1069,8 +1069,18 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             // Now let's make it officially a child agent
             sp.MakeChildAgent();
 
-            // Finally, let's close this previously-known-as-root agent, when the jump is outside the view zone
+            // May still need to signal neighbours whether child agents may need closing irrespective of whether this
+            // one needed closing.  Neighbour regions also contain logic to prevent a close if a subsequent move or
+            // teleport re-established the child connection.
+            // 
+            // It may be possible to also close child agents after a pause but one needs to be very careful about
+            // race conditions between different regions on rapid teleporting (e.g. from A1 to a non-neighbour B, back
+            // to a neighbour A2 then off to a non-neighbour C.  Also, closing child agents early may be more compatible
+            // with complicated scenarios where there a mixture of V1 and V2 teleports, though this is conjecture.  It's
+            // easier to close immediately and greatly reduce the scope of race conditions if possible.
+            sp.CloseChildAgents(newRegionX, newRegionY);
 
+            // Finally, let's close this previously-known-as-root agent, when the jump is outside the view zone
             if (NeedsClosing(sp.DrawDistance, oldRegionX, newRegionX, oldRegionY, newRegionY, reg))
             {
                 sp.DoNotCloseAfterTeleport = false;
@@ -1086,14 +1096,12 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 if (!sp.DoNotCloseAfterTeleport)
                 {
                     // OK, it got this agent. Let's close everything
-                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Closing in agent {0} in region {1}", sp.Name, Scene.Name);
-                    sp.CloseChildAgents(newRegionX, newRegionY);
+                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Closing agent {0} in {1}", sp.Name, Scene.Name);
                     sp.Scene.IncomingCloseAgent(sp.UUID, false);
-
                 }
                 else
                 {
-                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Not closing agent {0}, user is back in {0}", sp.Name, Scene.Name);
+                    m_log.DebugFormat("[ENTITY TRANSFER MODULE]: Not closing agent {0}, user is back in {1}", sp.Name, Scene.Name);
                     sp.DoNotCloseAfterTeleport = false;
                 }
             }
@@ -1836,10 +1844,10 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             List<ulong> newRegions = NewNeighbours(neighbourHandles, previousRegionNeighbourHandles);
             List<ulong> oldRegions = OldNeighbours(neighbourHandles, previousRegionNeighbourHandles);
 
-            //Dump("Current Neighbors", neighbourHandles);
-            //Dump("Previous Neighbours", previousRegionNeighbourHandles);
-            //Dump("New Neighbours", newRegions);
-            //Dump("Old Neighbours", oldRegions);
+//            Dump("Current Neighbors", neighbourHandles);
+//            Dump("Previous Neighbours", previousRegionNeighbourHandles);
+//            Dump("New Neighbours", newRegions);
+//            Dump("Old Neighbours", oldRegions);
 
             /// Update the scene presence's known regions here on this region
             sp.DropOldNeighbours(oldRegions);
@@ -1847,8 +1855,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             /// Collect as many seeds as possible
             Dictionary<ulong, string> seeds;
             if (sp.Scene.CapsModule != null)
-                seeds
-                    = new Dictionary<ulong, string>(sp.Scene.CapsModule.GetChildrenSeeds(sp.UUID));
+                seeds = new Dictionary<ulong, string>(sp.Scene.CapsModule.GetChildrenSeeds(sp.UUID));
             else
                 seeds = new Dictionary<ulong, string>();
 
@@ -1918,6 +1925,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                     newAgent = true;
                 else
                     newAgent = false;
+//                    continue;
 
                 if (neighbour.RegionHandle != sp.Scene.RegionInfo.RegionHandle)
                 {
diff --git a/OpenSim/Region/CoreModules/Scripting/ScriptModuleComms/ScriptModuleCommsModule.cs b/OpenSim/Region/CoreModules/Scripting/ScriptModuleComms/ScriptModuleCommsModule.cs
index bb304df..ad33f23 100644
--- a/OpenSim/Region/CoreModules/Scripting/ScriptModuleComms/ScriptModuleCommsModule.cs
+++ b/OpenSim/Region/CoreModules/Scripting/ScriptModuleComms/ScriptModuleCommsModule.cs
@@ -45,6 +45,7 @@ namespace OpenSim.Region.CoreModules.Scripting.ScriptModuleComms
     {
         private static readonly ILog m_log =
             LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        private static string LogHeader = "[MODULE COMMS]";
 
         private Dictionary<string,object> m_constants = new Dictionary<string,object>();
 
@@ -148,7 +149,7 @@ namespace OpenSim.Region.CoreModules.Scripting.ScriptModuleComms
             MethodInfo mi = GetMethodInfoFromType(target.GetType(), meth, true);
             if (mi == null)
             {
-                m_log.WarnFormat("[MODULE COMMANDS] Failed to register method {0}", meth);
+                m_log.WarnFormat("{0} Failed to register method {1}", LogHeader, meth);
                 return;
             }
 
@@ -165,7 +166,7 @@ namespace OpenSim.Region.CoreModules.Scripting.ScriptModuleComms
         {
 //            m_log.DebugFormat("[MODULE COMMANDS] Register method {0} from type {1}", mi.Name, (target is Type) ? ((Type)target).Name : target.GetType().Name);
 
-            Type delegateType;
+            Type delegateType = typeof(void);
             List<Type> typeArgs = mi.GetParameters()
                     .Select(p => p.ParameterType)
                     .ToList();
@@ -176,8 +177,16 @@ namespace OpenSim.Region.CoreModules.Scripting.ScriptModuleComms
             }
             else
             {
-                typeArgs.Add(mi.ReturnType);
-                delegateType = Expression.GetFuncType(typeArgs.ToArray());
+                try
+                {
+                    typeArgs.Add(mi.ReturnType);
+                    delegateType = Expression.GetFuncType(typeArgs.ToArray());
+                }
+                catch (Exception e)
+                {
+                    m_log.ErrorFormat("{0} Failed to create function signature. Most likely more than 5 parameters. Method={1}. Error={2}",
+                        LogHeader, mi.Name, e);
+                }
             }
 
             Delegate fcall;
diff --git a/OpenSim/Region/CoreModules/World/Estate/EstateManagementCommands.cs b/OpenSim/Region/CoreModules/World/Estate/EstateManagementCommands.cs
index 4d49794..173b603 100644
--- a/OpenSim/Region/CoreModules/World/Estate/EstateManagementCommands.cs
+++ b/OpenSim/Region/CoreModules/World/Estate/EstateManagementCommands.cs
@@ -76,6 +76,13 @@ namespace OpenSim.Region.CoreModules.World.Estate
                                " that coordinate. Corner # SW = 0, NW = 1, SE = 2, NE = 3, all corners = -1.",
                                consoleSetTerrainHeights);
 
+            m_module.Scene.AddCommand("Regions", m_module, "set water height",
+                               "set water height <height> [<x>] [<y>]",
+                               "Sets the water height in meters.  If <x> and <y> are specified, it will only set it on regions with a matching coordinate. " + 
+                               "Specify -1 in <x> or <y> to wildcard that coordinate.",
+                               consoleSetWaterHeight);
+
+
             m_module.Scene.AddCommand(
                 "Estates", m_module, "estate show", "estate show", "Shows all estates on the simulator.", ShowEstatesCommand);
         }       
@@ -121,7 +128,29 @@ namespace OpenSim.Region.CoreModules.World.Estate
                 }
             }
         }
- 
+        protected void consoleSetWaterHeight(string module, string[] args)
+        {
+            string heightstring = args[3];
+           
+            int x = (args.Length > 4 ? int.Parse(args[4]) : -1);
+            int y = (args.Length > 5 ? int.Parse(args[5]) : -1);
+
+            if (x == -1 || m_module.Scene.RegionInfo.RegionLocX == x)
+            {
+                if (y == -1 || m_module.Scene.RegionInfo.RegionLocY == y)
+                {
+                    double selectedheight = double.Parse(heightstring);
+
+                    m_log.Debug("[ESTATEMODULE]: Setting water height in " + m_module.Scene.RegionInfo.RegionName + " to " +
+                                string.Format(" {0}", selectedheight));
+                    m_module.Scene.RegionInfo.RegionSettings.WaterHeight = selectedheight;
+                    
+                    m_module.Scene.RegionInfo.RegionSettings.Save();
+                    m_module.TriggerRegionInfoChange();
+                    m_module.sendRegionHandshakeToAll();
+                }
+            }
+        }     
         protected void consoleSetTerrainHeights(string module, string[] args)
         {
             string num = args[3];
diff --git a/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs b/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs
index a5f5749..1808fdd 100644
--- a/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs
+++ b/OpenSim/Region/CoreModules/World/Estate/EstateManagementModule.cs
@@ -572,7 +572,7 @@ namespace OpenSim.Region.CoreModules.World.Estate
                                 if (!Scene.TeleportClientHome(user, s.ControllingClient))
                                 {
                                     s.ControllingClient.Kick("Your access to the region was revoked and TP home failed - you have been logged out.");
-                                    s.ControllingClient.Close();
+                                    Scene.IncomingCloseAgent(s.UUID, false);
                                 }
                             }
                         }
@@ -807,7 +807,7 @@ namespace OpenSim.Region.CoreModules.World.Estate
                     if (!Scene.TeleportClientHome(prey, s.ControllingClient))
                     {
                         s.ControllingClient.Kick("You were teleported home by the region owner, but the TP failed - you have been logged out.");
-                        s.ControllingClient.Close();
+                        Scene.IncomingCloseAgent(s.UUID, false);
                     }
                 }
             }
@@ -830,7 +830,7 @@ namespace OpenSim.Region.CoreModules.World.Estate
                         if (!Scene.TeleportClientHome(p.UUID, p.ControllingClient))
                         {
                             p.ControllingClient.Kick("You were teleported home by the region owner, but the TP failed - you have been logged out.");
-                            p.ControllingClient.Close();
+                            Scene.IncomingCloseAgent(p.UUID, false);
                         }
                     }
                 }
diff --git a/OpenSim/Region/Framework/Scenes/Scene.cs b/OpenSim/Region/Framework/Scenes/Scene.cs
index aa09092..6323a88 100644
--- a/OpenSim/Region/Framework/Scenes/Scene.cs
+++ b/OpenSim/Region/Framework/Scenes/Scene.cs
@@ -151,7 +151,7 @@ namespace OpenSim.Region.Framework.Scenes
         public SynchronizeSceneHandler SynchronizeScene;
 
         /// <summary>
-        /// Used to prevent simultaneous calls to RemoveClient() for the same agent from interfering with each other.
+        /// Used to prevent simultaneous calls to code that adds and removes agents.
         /// </summary>
         private object m_removeClientLock = new object();
 
@@ -1338,7 +1338,7 @@ namespace OpenSim.Region.Framework.Scenes
             Thread.Sleep(500);
 
             // Stop all client threads.
-            ForEachScenePresence(delegate(ScenePresence avatar) { avatar.ControllingClient.Close(); });
+            ForEachScenePresence(delegate(ScenePresence avatar) { IncomingCloseAgent(avatar.UUID, false); });
 
             m_log.Debug("[SCENE]: TriggerSceneShuttingDown");
             EventManager.TriggerSceneShuttingDown(this);
@@ -3127,7 +3127,8 @@ namespace OpenSim.Region.Framework.Scenes
                         if (sp != null)
                         {
                             PresenceService.LogoutAgent(sp.ControllingClient.SessionId);
-                            sp.ControllingClient.Close();
+
+                            IncomingCloseAgent(sp.UUID, false);
                         }
 
                         // BANG! SLASH!
@@ -3541,47 +3542,48 @@ namespace OpenSim.Region.Framework.Scenes
 
         public override void RemoveClient(UUID agentID, bool closeChildAgents)
         {
-//            CheckHeartbeat();
-            bool isChildAgent = false;
-            AgentCircuitData acd;
+            AgentCircuitData acd = m_authenticateHandler.GetAgentCircuitData(agentID);
 
-            lock (m_removeClientLock)
+            // Shouldn't be necessary since RemoveClient() is currently only called by IClientAPI.Close() which 
+            // in turn is only called by Scene.IncomingCloseAgent() which checks whether the presence exists or not
+            // However, will keep for now just in case.
+            if (acd == null)
             {
-                acd = m_authenticateHandler.GetAgentCircuitData(agentID);
+                m_log.ErrorFormat(
+                    "[SCENE]: No agent circuit found for {0} in {1}, aborting Scene.RemoveClient", agentID, Name);
 
-                if (acd == null)
-                {
-                    m_log.ErrorFormat("[SCENE]: No agent circuit found for {0}, aborting Scene.RemoveClient", agentID);
-                    return;
-                }
-                else
-                {
-                    // We remove the acd up here to avoid later race conditions if two RemoveClient() calls occurred
-                    // simultaneously.
-                    // We also need to remove by agent ID since NPCs will have no circuit code.
-                    m_authenticateHandler.RemoveCircuit(agentID);
-                }
+                return;
+            }
+            else
+            {
+                m_authenticateHandler.RemoveCircuit(agentID);
             }
 
+            // TODO: Can we now remove this lock?
             lock (acd)
-            {
+            {    
+                bool isChildAgent = false;
+
                 ScenePresence avatar = GetScenePresence(agentID);
-    
+ 
+                // Shouldn't be necessary since RemoveClient() is currently only called by IClientAPI.Close() which 
+                // in turn is only called by Scene.IncomingCloseAgent() which checks whether the presence exists or not
+                // However, will keep for now just in case.
                 if (avatar == null)
                 {
-                    m_log.WarnFormat(
+                    m_log.ErrorFormat(
                         "[SCENE]: Called RemoveClient() with agent ID {0} but no such presence is in the scene.", agentID);
     
                     return;
                 }
-    
+
                 try
                 {
                     isChildAgent = avatar.IsChildAgent;
 
                     m_log.DebugFormat(
                         "[SCENE]: Removing {0} agent {1} {2} from {3}",
-                        (isChildAgent ? "child" : "root"), avatar.Name, agentID, RegionInfo.RegionName);
+                        isChildAgent ? "child" : "root", avatar.Name, agentID, Name);
     
                     // Don't do this to root agents, it's not nice for the viewer
                     if (closeChildAgents && isChildAgent)
@@ -3745,13 +3747,13 @@ namespace OpenSim.Region.Framework.Scenes
         /// is activated later when the viewer sends the initial UseCircuitCodePacket UDP packet (in the case of
         /// the LLUDP stack).
         /// </remarks>
-        /// <param name="agent">CircuitData of the agent who is connecting</param>
+        /// <param name="acd">CircuitData of the agent who is connecting</param>
         /// <param name="reason">Outputs the reason for the false response on this string</param>
         /// <param name="requirePresenceLookup">True for normal presence. False for NPC
         /// or other applications where a full grid/Hypergrid presence may not be required.</param>
         /// <returns>True if the region accepts this agent.  False if it does not.  False will 
         /// also return a reason.</returns>
-        public bool NewUserConnection(AgentCircuitData agent, uint teleportFlags, out string reason, bool requirePresenceLookup)
+        public bool NewUserConnection(AgentCircuitData acd, uint teleportFlags, out string reason, bool requirePresenceLookup)
         {
             bool vialogin = ((teleportFlags & (uint)TPFlags.ViaLogin) != 0 ||
                 (teleportFlags & (uint)TPFlags.ViaHGLogin) != 0);
@@ -3771,15 +3773,15 @@ namespace OpenSim.Region.Framework.Scenes
             m_log.DebugFormat(
                 "[SCENE]: Region {0} told of incoming {1} agent {2} {3} {4} (circuit code {5}, IP {6}, viewer {7}, teleportflags ({8}), position {9})",
                 RegionInfo.RegionName,
-                (agent.child ? "child" : "root"),
-                agent.firstname,
-                agent.lastname,
-                agent.AgentID,
-                agent.circuitcode,
-                agent.IPAddress,
-                agent.Viewer,
+                (acd.child ? "child" : "root"),
+                acd.firstname,
+                acd.lastname,
+                acd.AgentID,
+                acd.circuitcode,
+                acd.IPAddress,
+                acd.Viewer,
                 ((TPFlags)teleportFlags).ToString(),
-                agent.startpos
+                acd.startpos
             );
 
             if (!LoginsEnabled)
@@ -3797,7 +3799,7 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 foreach (string viewer in m_AllowedViewers)
                 {
-                    if (viewer == agent.Viewer.Substring(0, viewer.Length).Trim().ToLower())
+                    if (viewer == acd.Viewer.Substring(0, viewer.Length).Trim().ToLower())
                     {
                         ViewerDenied = false;
                         break;
@@ -3814,7 +3816,7 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 foreach (string viewer in m_BannedViewers)
                 {
-                    if (viewer == agent.Viewer.Substring(0, viewer.Length).Trim().ToLower())
+                    if (viewer == acd.Viewer.Substring(0, viewer.Length).Trim().ToLower())
                     {
                         ViewerDenied = true;
                         break;
@@ -3826,61 +3828,115 @@ namespace OpenSim.Region.Framework.Scenes
             {
                 m_log.DebugFormat(
                     "[SCENE]: Access denied for {0} {1} using {2}",
-                    agent.firstname, agent.lastname, agent.Viewer);
+                    acd.firstname, acd.lastname, acd.Viewer);
                 reason = "Access denied, your viewer is banned by the region owner";
                 return false;
-            }           
+            }
+
+            ILandObject land;
+            ScenePresence sp;
 
-            lock (agent)
+            lock (m_removeClientLock)
             {
-                ScenePresence sp = GetScenePresence(agent.AgentID);
-    
-                if (sp != null)
+                sp = GetScenePresence(acd.AgentID);
+
+                // We need to ensure that we are not already removing the scene presence before we ask it not to be 
+                // closed.
+                if (sp != null && sp.IsChildAgent && sp.LifecycleState == ScenePresenceState.Running)
                 {
-                    if (!sp.IsChildAgent)
-                    {
-                        // We have a root agent. Is it in transit?
-                        if (!EntityTransferModule.IsInTransit(sp.UUID))
-                        {
-                            // We have a zombie from a crashed session. 
-                            // Or the same user is trying to be root twice here, won't work.
-                            // Kill it.
-                            m_log.WarnFormat(
-                                "[SCENE]: Existing root scene presence detected for {0} {1} in {2} when connecting.  Removing existing presence.",
-                                sp.Name, sp.UUID, RegionInfo.RegionName);
+                    m_log.DebugFormat(
+                        "[SCENE]: Reusing existing child scene presence for {0} in {1}", sp.Name, Name);
 
-                            if (sp.ControllingClient != null)
-                                sp.ControllingClient.Close(true, true);
+                    // In the case where, for example, an A B C D region layout, an avatar may
+                    // teleport from A -> D, but then -> C before A has asked B to close its old child agent.  When C
+                    // renews the lease on the child agent at B, we must make sure that the close from A does not succeed.
+                    if (!acd.ChildrenCapSeeds.ContainsKey(RegionInfo.RegionHandle))
+                    {
+                        m_log.DebugFormat(
+                            "[SCENE]: Setting DoNotCloseAfterTeleport for child scene presence {0} in {1} because source will attempt close.", 
+                            sp.Name, Name);
 
-                            sp = null;
-                        }
-                        //else
-                        //    m_log.WarnFormat("[SCENE]: Existing root scene presence for {0} {1} in {2}, but agent is in trasit", sp.Name, sp.UUID, RegionInfo.RegionName);
+                        sp.DoNotCloseAfterTeleport = true;
                     }
-                    else
+                    else if (EntityTransferModule.IsInTransit(sp.UUID))
                     {
-                        // We have a child agent here
+                        m_log.DebugFormat(
+                            "[SCENE]: Setting DoNotCloseAfterTeleport for child scene presence {0} in {1} because this region will attempt previous end-of-teleport close.", 
+                            sp.Name, Name);
+
                         sp.DoNotCloseAfterTeleport = true;
-                        //m_log.WarnFormat("[SCENE]: Existing child scene presence for {0} {1} in {2}", sp.Name, sp.UUID, RegionInfo.RegionName);
                     }
                 }
+            }
+
+            // Need to poll here in case we are currently deleting an sp.  Letting threads run over each other will
+            // allow unpredictable things to happen.
+            if (sp != null)
+            {
+                const int polls = 10;
+                const int pollInterval = 1000;
+                int pollsLeft = polls;
+
+                while (sp.LifecycleState == ScenePresenceState.Removing && pollsLeft-- > 0)
+                    Thread.Sleep(pollInterval);
+
+                if (sp.LifecycleState == ScenePresenceState.Removing)
+                {
+                    m_log.WarnFormat(
+                        "[SCENE]: Agent {0} in {1} was still being removed after {2}s.  Aborting NewUserConnection.", 
+                        sp.Name, Name, polls * pollInterval / 1000);
+
+                    return false;
+                }
+                else if (polls != pollsLeft)
+                {
+                    m_log.DebugFormat(
+                        "[SCENE]: NewUserConnection for agent {0} in {1} had to wait {2}s for in-progress removal to complete on an old presence.",
+                        sp.Name, Name, polls * pollInterval / 1000);
+                }
+            }
+
+            // TODO: can we remove this lock?
+            lock (acd)
+            {
+                if (sp != null && !sp.IsChildAgent)
+                {
+                    // We have a root agent. Is it in transit?
+                    if (!EntityTransferModule.IsInTransit(sp.UUID))
+                    {
+                        // We have a zombie from a crashed session. 
+                        // Or the same user is trying to be root twice here, won't work.
+                        // Kill it.
+                        m_log.WarnFormat(
+                            "[SCENE]: Existing root scene presence detected for {0} {1} in {2} when connecting.  Removing existing presence.",
+                            sp.Name, sp.UUID, RegionInfo.RegionName);
+
+                        if (sp.ControllingClient != null)
+                            IncomingCloseAgent(sp.UUID, true);
+
+                        sp = null;
+                    }
+                    //else
+                    //    m_log.WarnFormat("[SCENE]: Existing root scene presence for {0} {1} in {2}, but agent is in trasit", sp.Name, sp.UUID, RegionInfo.RegionName);
+                }
 
                 // Optimistic: add or update the circuit data with the new agent circuit data and teleport flags.
                 // We need the circuit data here for some of the subsequent checks. (groups, for example)
                 // If the checks fail, we remove the circuit.
-                agent.teleportFlags = teleportFlags;
-                m_authenticateHandler.AddNewCircuit(agent.circuitcode, agent);
+                acd.teleportFlags = teleportFlags;
+                m_authenticateHandler.AddNewCircuit(acd.circuitcode, acd);
 
+                land = LandChannel.GetLandObject(acd.startpos.X, acd.startpos.Y);
+    
                 // On login test land permisions
                 if (vialogin)
                 {
                     IUserAccountCacheModule cache = RequestModuleInterface<IUserAccountCacheModule>();
                     if (cache != null)
-                        cache.Remove(agent.firstname + " " + agent.lastname);
-                    if (!TestLandRestrictions(agent.AgentID, out reason, ref agent.startpos.X, ref agent.startpos.Y))
+                        cache.Remove(acd.firstname + " " + acd.lastname);
+                    if (land != null && !TestLandRestrictions(acd.AgentID, out reason, ref acd.startpos.X, ref acd.startpos.Y))
                     {
-                        m_log.DebugFormat("[CONNECTION BEGIN]: Denying access to {0} due to no land access", agent.AgentID.ToString());
-                        m_authenticateHandler.RemoveCircuit(agent.circuitcode);
+                        m_authenticateHandler.RemoveCircuit(acd.circuitcode);
                         return false;
                     }
                 }
@@ -3891,9 +3947,9 @@ namespace OpenSim.Region.Framework.Scenes
                     {
                         try
                         {
-                            if (!VerifyUserPresence(agent, out reason))
+                            if (!VerifyUserPresence(acd, out reason))
                             {
-                                m_authenticateHandler.RemoveCircuit(agent.circuitcode);
+                                m_authenticateHandler.RemoveCircuit(acd.circuitcode);
                                 return false;
                             }
                         }
@@ -3902,16 +3958,16 @@ namespace OpenSim.Region.Framework.Scenes
                             m_log.ErrorFormat(
                                 "[SCENE]: Exception verifying presence {0}{1}", e.Message, e.StackTrace);
 
-                            m_authenticateHandler.RemoveCircuit(agent.circuitcode);
+                            m_authenticateHandler.RemoveCircuit(acd.circuitcode);
                             return false;
                         }
                     }
 
                     try
                     {
-                        if (!AuthorizeUser(agent, SeeIntoRegion, out reason))
+                        if (!AuthorizeUser(acd, SeeIntoRegion, out reason))
                         {
-                            m_authenticateHandler.RemoveCircuit(agent.circuitcode);
+                            m_authenticateHandler.RemoveCircuit(acd.circuitcode);
                             return false;
                         }
                     }
@@ -3920,15 +3976,20 @@ namespace OpenSim.Region.Framework.Scenes
                         m_log.ErrorFormat(
                             "[SCENE]: Exception authorizing user {0}{1}", e.Message, e.StackTrace);
 
-                        m_authenticateHandler.RemoveCircuit(agent.circuitcode);
+                        m_authenticateHandler.RemoveCircuit(acd.circuitcode);
                         return false;
                     }
 
                     m_log.InfoFormat(
                         "[SCENE]: Region {0} authenticated and authorized incoming {1} agent {2} {3} {4} (circuit code {5})",
-                        RegionInfo.RegionName, (agent.child ? "child" : "root"), agent.firstname, agent.lastname,
-                        agent.AgentID, agent.circuitcode);
-
+                        Name, (acd.child ? "child" : "root"), acd.firstname, acd.lastname,
+                        acd.AgentID, acd.circuitcode);
+    
+                    if (CapsModule != null)
+                    {
+                        CapsModule.SetAgentCapsSeeds(acd);
+                        CapsModule.CreateCaps(acd.AgentID, acd.circuitcode);
+                    }
                 }
                 else
                 {
@@ -3940,14 +4001,14 @@ namespace OpenSim.Region.Framework.Scenes
                     {
                         m_log.DebugFormat(
                             "[SCENE]: Adjusting known seeds for existing agent {0} in {1}",
-                            agent.AgentID, RegionInfo.RegionName);
-
+                            acd.AgentID, RegionInfo.RegionName);
+    
                         sp.AdjustKnownSeeds();
 
                         if (CapsModule != null)
                         {
-                            CapsModule.SetAgentCapsSeeds(agent);
-                            CapsModule.CreateCaps(agent.AgentID, agent.circuitcode);
+                            CapsModule.SetAgentCapsSeeds(acd);
+                            CapsModule.CreateCaps(acd.AgentID, acd.circuitcode);
                         }
                     }
                 }
@@ -3955,28 +4016,28 @@ namespace OpenSim.Region.Framework.Scenes
                 // Try caching an incoming user name much earlier on to see if this helps with an issue
                 // where HG users are occasionally seen by others as "Unknown User" because their UUIDName
                 // request for the HG avatar appears to trigger before the user name is cached.
-                CacheUserName(null, agent);
+                CacheUserName(null, acd);
             }
 
             if (CapsModule != null)
             {
-                CapsModule.ActivateCaps(agent.circuitcode);
+                CapsModule.ActivateCaps(acd.circuitcode);
             }
 
             if (vialogin)
             {
 //                CleanDroppedAttachments();
 
-                if (TestBorderCross(agent.startpos, Cardinals.E))
+                if (TestBorderCross(acd.startpos, Cardinals.E))
                 {
-                    Border crossedBorder = GetCrossedBorder(agent.startpos, Cardinals.E);
-                    agent.startpos.X = crossedBorder.BorderLine.Z - 1;
+                    Border crossedBorder = GetCrossedBorder(acd.startpos, Cardinals.E);
+                    acd.startpos.X = crossedBorder.BorderLine.Z - 1;
                 }
 
-                if (TestBorderCross(agent.startpos, Cardinals.N))
+                if (TestBorderCross(acd.startpos, Cardinals.N))
                 {
-                    Border crossedBorder = GetCrossedBorder(agent.startpos, Cardinals.N);
-                    agent.startpos.Y = crossedBorder.BorderLine.Z - 1;
+                    Border crossedBorder = GetCrossedBorder(acd.startpos, Cardinals.N);
+                    acd.startpos.Y = crossedBorder.BorderLine.Z - 1;
                 }
 
                 //Mitigate http://opensimulator.org/mantis/view.php?id=3522
@@ -3986,39 +4047,39 @@ namespace OpenSim.Region.Framework.Scenes
                 {
                     lock (EastBorders)
                     {
-                        if (agent.startpos.X > EastBorders[0].BorderLine.Z)
+                        if (acd.startpos.X > EastBorders[0].BorderLine.Z)
                         {
                             m_log.Warn("FIX AGENT POSITION");
-                            agent.startpos.X = EastBorders[0].BorderLine.Z * 0.5f;
-                            if (agent.startpos.Z > 720)
-                                agent.startpos.Z = 720;
+                            acd.startpos.X = EastBorders[0].BorderLine.Z * 0.5f;
+                            if (acd.startpos.Z > 720)
+                                acd.startpos.Z = 720;
                         }
                     }
                     lock (NorthBorders)
                     {
-                        if (agent.startpos.Y > NorthBorders[0].BorderLine.Z)
+                        if (acd.startpos.Y > NorthBorders[0].BorderLine.Z)
                         {
                             m_log.Warn("FIX Agent POSITION");
-                            agent.startpos.Y = NorthBorders[0].BorderLine.Z * 0.5f;
-                            if (agent.startpos.Z > 720)
-                                agent.startpos.Z = 720;
+                            acd.startpos.Y = NorthBorders[0].BorderLine.Z * 0.5f;
+                            if (acd.startpos.Z > 720)
+                                acd.startpos.Z = 720;
                         }
                     }
                 } else
                 {
-                    if (agent.startpos.X > EastBorders[0].BorderLine.Z)
+                    if (acd.startpos.X > EastBorders[0].BorderLine.Z)
                     {
                         m_log.Warn("FIX AGENT POSITION");
-                        agent.startpos.X = EastBorders[0].BorderLine.Z * 0.5f;
-                        if (agent.startpos.Z > 720)
-                            agent.startpos.Z = 720;
+                        acd.startpos.X = EastBorders[0].BorderLine.Z * 0.5f;
+                        if (acd.startpos.Z > 720)
+                            acd.startpos.Z = 720;
                     }
-                    if (agent.startpos.Y > NorthBorders[0].BorderLine.Z)
+                    if (acd.startpos.Y > NorthBorders[0].BorderLine.Z)
                     {
                         m_log.Warn("FIX Agent POSITION");
-                        agent.startpos.Y = NorthBorders[0].BorderLine.Z * 0.5f;
-                        if (agent.startpos.Z > 720)
-                            agent.startpos.Z = 720;
+                        acd.startpos.Y = NorthBorders[0].BorderLine.Z * 0.5f;
+                        if (acd.startpos.Z > 720)
+                            acd.startpos.Z = 720;
                     }
                 }
 
@@ -4034,12 +4095,12 @@ namespace OpenSim.Region.Framework.Scenes
                     {
                         // We have multiple SpawnPoints, Route the agent to a random or sequential one
                         if (SpawnPointRouting == "random")
-                            agent.startpos = spawnpoints[Util.RandomClass.Next(spawnpoints.Count) - 1].GetLocation(
+                            acd.startpos = spawnpoints[Util.RandomClass.Next(spawnpoints.Count) - 1].GetLocation(
                                 telehub.AbsolutePosition,
                                 telehub.GroupRotation
                             );
                         else
-                            agent.startpos = spawnpoints[SpawnPoint()].GetLocation(
+                            acd.startpos = spawnpoints[SpawnPoint()].GetLocation(
                                 telehub.AbsolutePosition,
                                 telehub.GroupRotation
                             );
@@ -4047,7 +4108,7 @@ namespace OpenSim.Region.Framework.Scenes
                     else
                     {
                         // We have a single SpawnPoint and will route the agent to it
-                        agent.startpos = spawnpoints[0].GetLocation(telehub.AbsolutePosition, telehub.GroupRotation);
+                        acd.startpos = spawnpoints[0].GetLocation(telehub.AbsolutePosition, telehub.GroupRotation);
                     }
 
                     return true;
@@ -4060,7 +4121,7 @@ namespace OpenSim.Region.Framework.Scenes
                 {
                     if (land.LandData.LandingType == (byte)1 && land.LandData.UserLocation != Vector3.Zero)
                     {
-                        agent.startpos = land.LandData.UserLocation;
+                        acd.startpos = land.LandData.UserLocation;
                     }
                 }
                 */// This is now handled properly in ScenePresence.MakeRootAgent
@@ -4444,24 +4505,25 @@ namespace OpenSim.Region.Framework.Scenes
             ScenePresence childAgentUpdate = GetScenePresence(cAgentData.AgentID);
             if (childAgentUpdate != null)
             {
-                if (childAgentUpdate.ControllingClient.SessionId == cAgentData.SessionID)
+                if (childAgentUpdate.ControllingClient.SessionId != cAgentData.SessionID)
+                    // Only warn for now
+                    m_log.WarnFormat("[SCENE]: Attempt at updating position of agent {0} with invalid session id {1}. Neighbor running older version?", 
+                        childAgentUpdate.UUID, cAgentData.SessionID);
+
+                // I can't imagine *yet* why we would get an update if the agent is a root agent..
+                // however to avoid a race condition crossing borders..
+                if (childAgentUpdate.IsChildAgent)
                 {
-                    // I can't imagine *yet* why we would get an update if the agent is a root agent..
-                    // however to avoid a race condition crossing borders..
-                    if (childAgentUpdate.IsChildAgent)
-                    {
-                        uint rRegionX = (uint)(cAgentData.RegionHandle >> 40);
-                        uint rRegionY = (((uint)(cAgentData.RegionHandle)) >> 8);
-                        uint tRegionX = RegionInfo.RegionLocX;
-                        uint tRegionY = RegionInfo.RegionLocY;
-                        //Send Data to ScenePresence
-                        childAgentUpdate.ChildAgentDataUpdate(cAgentData, tRegionX, tRegionY, rRegionX, rRegionY);
-                        // Not Implemented:
-                        //TODO: Do we need to pass the message on to one of our neighbors?
-                    }
+                    uint rRegionX = (uint)(cAgentData.RegionHandle >> 40);
+                    uint rRegionY = (((uint)(cAgentData.RegionHandle)) >> 8);
+                    uint tRegionX = RegionInfo.RegionLocX;
+                    uint tRegionY = RegionInfo.RegionLocY;
+                    //Send Data to ScenePresence
+                    childAgentUpdate.ChildAgentDataUpdate(cAgentData, tRegionX, tRegionY, rRegionX, rRegionY);
+                    // Not Implemented:
+                    //TODO: Do we need to pass the message on to one of our neighbors?
                 }
-                else
-                    m_log.WarnFormat("[SCENE]: Attempt at updating position of agent {0} with invalid session id {1}", childAgentUpdate.UUID, cAgentData.SessionID);
+
                 return true;
             }
 
@@ -4540,11 +4602,51 @@ namespace OpenSim.Region.Framework.Scenes
         /// </param>
         public bool IncomingCloseAgent(UUID agentID, bool force)
         {
-            //m_log.DebugFormat("[SCENE]: Processing incoming close agent for {0}", agentID);
-            ScenePresence presence = m_sceneGraph.GetScenePresence(agentID);
-            if (presence != null)
+            ScenePresence sp;
+
+            lock (m_removeClientLock)
+            {
+                sp = GetScenePresence(agentID);
+    
+                if (sp == null)
+                {
+                    m_log.DebugFormat(
+                        "[SCENE]: Called RemoveClient() with agent ID {0} but no such presence is in {1}", 
+                        agentID, Name);
+    
+                    return false;
+                }
+
+                if (sp.LifecycleState != ScenePresenceState.Running)
+                {
+                    m_log.DebugFormat(
+                        "[SCENE]: Called RemoveClient() for {0} in {1} but presence is already in state {2}",
+                        sp.Name, Name, sp.LifecycleState);
+
+                    return false;
+                }
+
+                // We need to avoid a race condition where in, for example, an A B C D region layout, an avatar may
+                // teleport from A -> D, but then -> C before A has asked B to close its old child agent.  We do not
+                // want to obey this close since C may have renewed the child agent lease on B.
+                if (sp.DoNotCloseAfterTeleport)
+                {
+                    m_log.DebugFormat(
+                        "[SCENE]: Not closing {0} agent {1} in {2} since another simulator has re-established the child connection",
+                        sp.IsChildAgent ? "child" : "root", sp.Name, Name);
+
+                    // Need to reset the flag so that a subsequent close after another teleport can succeed.
+                    sp.DoNotCloseAfterTeleport = false;
+
+                    return false;
+                }
+
+                sp.LifecycleState = ScenePresenceState.Removing;
+            }
+
+            if (sp != null)
             {
-                presence.ControllingClient.Close(force, force);
+                sp.ControllingClient.Close(force, force);
                 return true;
             }
 
diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 48bf6f3..5301a82 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -75,6 +75,8 @@ namespace OpenSim.Region.Framework.Scenes
 
     public class ScenePresence : EntityBase, IScenePresence
     {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
 //        ~ScenePresence()
 //        {
 //            m_log.DebugFormat("[SCENE PRESENCE]: Destructor called on {0}", Name);
@@ -86,10 +88,27 @@ namespace OpenSim.Region.Framework.Scenes
                 m_scene.EventManager.TriggerScenePresenceUpdated(this);
         }
 
-        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
-
         public PresenceType PresenceType { get; private set; }
 
+        private ScenePresenceStateMachine m_stateMachine;
+
+        /// <summary>
+        /// The current state of this presence.  Governs only the existence lifecycle.  See ScenePresenceStateMachine
+        /// for more details.
+        /// </summary>
+        public ScenePresenceState LifecycleState 
+        { 
+            get
+            {
+                return m_stateMachine.GetState();
+            }
+
+            set
+            {
+                m_stateMachine.SetState(value);
+            }
+        }
+
 //        private static readonly byte[] DEFAULT_TEXTURE = AvatarAppearance.GetDefaultTexture().GetBytes();
         private static readonly Array DIR_CONTROL_FLAGS = Enum.GetValues(typeof(Dir_ControlFlags));
         private static readonly Vector3 HEAD_ADJUSTMENT = new Vector3(0f, 0f, 0.3f);
@@ -299,9 +318,9 @@ namespace OpenSim.Region.Framework.Scenes
         /// <summary>
         /// In the V1 teleport protocol, the destination simulator sends ReleaseAgent to this address.
         /// </summary>
-        string m_callbackURI;
+        private string m_callbackURI;
 
-        UUID m_originRegionID;
+        public UUID m_originRegionID;
 
         /// <summary>
         /// Used by the entity transfer module to signal when the presence should not be closed because a subsequent
@@ -813,7 +832,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         public ScenePresence(
             IClientAPI client, Scene world, AvatarAppearance appearance, PresenceType type)
-        {
+        {            
             AttachmentsSyncLock = new Object();
             AllowMovement = true;
             IsChildAgent = true;
@@ -859,6 +878,8 @@ namespace OpenSim.Region.Framework.Scenes
             SetDirectionVectors();
 
             Appearance = appearance;
+
+            m_stateMachine = new ScenePresenceStateMachine(this);
         }
 
         private void RegionHeartbeatEnd(Scene scene)
@@ -956,7 +977,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// </summary>
         public void MakeRootAgent(Vector3 pos, bool isFlying)
         {
-            m_log.DebugFormat(
+            m_log.InfoFormat(
                 "[SCENE]: Upgrading child to root agent for {0} in {1}",
                 Name, m_scene.RegionInfo.RegionName);
 
@@ -996,6 +1017,11 @@ namespace OpenSim.Region.Framework.Scenes
 
             IsChildAgent = false;
 
+            // Must reset this here so that a teleport to a region next to an existing region does not keep the flag
+            // set and prevent the close of the connection on a subsequent re-teleport.
+            // Should not be needed if we are not trying to tell this region to close
+//            DoNotCloseAfterTeleport = false;
+
             IGroupsModule gm = m_scene.RequestModuleInterface<IGroupsModule>();
             if (gm != null)
                 Grouptitle = gm.GetGroupTitle(m_uuid);
@@ -1520,7 +1546,7 @@ namespace OpenSim.Region.Framework.Scenes
         private bool WaitForUpdateAgent(IClientAPI client)
         {
             // Before UpdateAgent, m_originRegionID is UUID.Zero; after, it's non-Zero
-            int count = 20;
+            int count = 50;
             while (m_originRegionID.Equals(UUID.Zero) && count-- > 0)
             {
                 m_log.DebugFormat("[SCENE PRESENCE]: Agent {0} waiting for update in {1}", client.Name, Scene.Name);
@@ -3994,6 +4020,7 @@ namespace OpenSim.Region.Framework.Scenes
 //                Animator.Close();
             Animator = null;
 
+            LifecycleState = ScenePresenceState.Removed;
         }
 
         public void AddAttachment(SceneObjectGroup gobj)
diff --git a/OpenSim/Region/Framework/Scenes/ScenePresenceStateMachine.cs b/OpenSim/Region/Framework/Scenes/ScenePresenceStateMachine.cs
new file mode 100644
index 0000000..dc3a212
--- /dev/null
+++ b/OpenSim/Region/Framework/Scenes/ScenePresenceStateMachine.cs
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+
+namespace OpenSim.Region.Framework.Scenes
+{
+    /// <summary>
+    /// The possible states that a scene presence can be in.  This is currently orthagonal to whether a scene presence
+    /// is root or child.
+    /// </summary>
+    /// <remarks>
+    /// This is a state machine.
+    ///
+    /// [Entry]               => Running
+    /// Running               => Removing
+    /// Removing              => Removed
+    /// 
+    /// All other methods should only see the scene presence in running state - this is the normal operational state
+    /// Removed state occurs when the presence has been removed.  This is the end state with no exit.
+    /// </remarks>
+    public enum ScenePresenceState
+    {
+        Running,                // Normal operation state.  The scene presence is available.
+        Removing,               // The presence is in the process of being removed from the scene via Scene.RemoveClient.
+        Removed,                // The presence has been removed from the scene and is effectively dead.
+                                // There is no exit from this state.
+    }
+
+    internal class ScenePresenceStateMachine
+    {
+        private ScenePresence m_sp;
+        private ScenePresenceState m_state;
+
+        internal ScenePresenceStateMachine(ScenePresence sp)
+        {
+            m_sp = sp;
+            m_state = ScenePresenceState.Running;
+        }
+
+        internal ScenePresenceState GetState()
+        {
+            return m_state;
+        }
+
+        /// <summary>
+        /// Updates the state of an agent that is already in transit.
+        /// </summary>
+        /// <param name='id'></param>
+        /// <param name='newState'></param>
+        /// <returns></returns>
+        /// <exception cref='Exception'>Illegal transitions will throw an Exception</exception>
+        internal void SetState(ScenePresenceState newState)
+        {
+            bool transitionOkay = false;
+
+            lock (this)
+            {
+                if (newState == ScenePresenceState.Removing && m_state == ScenePresenceState.Running)
+                    transitionOkay = true;
+                else if (newState == ScenePresenceState.Removed && m_state == ScenePresenceState.Removing)
+                    transitionOkay = true;
+            }           
+
+            if (!transitionOkay)
+            {
+                throw new Exception(
+                    string.Format(
+                        "Scene presence {0} is not allowed to move from state {1} to new state {2} in {3}",
+                        m_sp.Name, m_state, newState, m_sp.Scene.Name));
+            }
+            else
+            {
+                m_state = newState;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 58a417e..9af3dce 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -96,8 +96,8 @@ public sealed class BSCharacter : BSPhysObject
         m_moveActor = new BSActorAvatarMove(PhysScene, this, AvatarMoveActorName);
         PhysicalActors.Add(AvatarMoveActorName, m_moveActor);
 
-        DetailLog("{0},BSCharacter.create,call,size={1},scale={2},density={3},volume={4},mass={5}",
-                            LocalID, _size, Scale, Density, _avatarVolume, RawMass);
+        DetailLog("{0},BSCharacter.create,call,size={1},scale={2},density={3},volume={4},mass={5},pos={6}",
+                            LocalID, _size, Scale, Density, _avatarVolume, RawMass, pos);
 
         // do actual creation in taint time
         PhysScene.TaintedObject("BSCharacter.create", delegate()
@@ -190,6 +190,10 @@ public sealed class BSCharacter : BSPhysObject
         }
 
         set {
+            // This is how much the avatar size is changing. Positive means getting bigger.
+            // The avatar altitude must be adjusted for this change.
+            float heightChange = value.Z - _size.Z;
+
             _size = value;
             // Old versions of ScenePresence passed only the height. If width and/or depth are zero,
             //     replace with the default values.
@@ -207,6 +211,10 @@ public sealed class BSCharacter : BSPhysObject
                 {
                     PhysScene.PE.SetLocalScaling(PhysShape.physShapeInfo, Scale);
                     UpdatePhysicalMassProperties(RawMass, true);
+
+                    // Adjust the avatar's position to account for the increase/decrease in size
+                    ForcePosition = new OMV.Vector3(RawPosition.X, RawPosition.Y, RawPosition.Z + heightChange / 2f);
+
                     // Make sure this change appears as a property update event
                     PhysScene.PE.PushUpdate(PhysBody);
                 }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
index 4520171..fcb892a 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
@@ -570,9 +570,9 @@ public static class BSParam
         new ParameterDefn<float>("AvatarHeightLowFudge", "A fudge factor to make small avatars stand on the ground",
             -0.2f ),
         new ParameterDefn<float>("AvatarHeightMidFudge", "A fudge distance to adjust average sized avatars to be standing on ground",
-            0.1f ),
+            0.2f ),
         new ParameterDefn<float>("AvatarHeightHighFudge", "A fudge factor to make tall avatars stand on the ground",
-            0.1f ),
+            0.2f ),
             new ParameterDefn<float>("AvatarContactProcessingThreshold", "Distance from capsule to check for collisions",
             0.1f ),
             new ParameterDefn<float>("AvatarBelowGroundUpCorrectionMeters", "Meters to move avatar up if it seems to be below ground",