Try to resolve some problems with viewers crashing after hitting parcel banlines or freezing on the banline.

This involves
1) On forcible teleport, call m_scene.RequestTeleportLocation() rather than ScenePresence.Teleport() - only EntityTransferModule now should call SP.Teleport()
2) When avatar is being forcibly moved due to banlines, use a 'stop movement' tolerance of 0.2 to requested position rather than 1
This prevents the avatar sometimes being stuck to banlines until they teleport somewhere else.
This aims to fix some problems in http://opensimulator.org/mantis/view.php?id=5822

OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs

@@ -94,8 +94,11 @@ namespace OpenSim.Region.CoreModules.World.Land
 
         // caches ExtendedLandData
         private Cache parcelInfoCache;
-        private Dictionary<UUID, Vector3> forcedPosition =
+
-                new Dictionary<UUID, Vector3>();
+        /// <summary>
+        /// Record positions that avatar's are currently being forced to move to due to parcel entry restrictions.
+        /// </summary>
+        private Dictionary<UUID, Vector3> forcedPosition = new Dictionary<UUID, Vector3>();
 
         #region INonSharedRegionModule Members
 
@@ -224,22 +227,34 @@ namespace OpenSim.Region.CoreModules.World.Land
                 //When the avatar walks into a ban line on the ground, it prevents getting stuck
                 agentData.ControlFlags = (uint)AgentManager.ControlFlags.AGENT_CONTROL_FLY;
 
-
                 //Make sure we stop if they get about to the right place to prevent yoyo and prevents getting stuck on banlines
                 if (Vector3.Distance(clientAvatar.AbsolutePosition, forcedPosition[remoteClient.AgentId]) < .2)
                 {
-                    Debug.WriteLine(string.Format("Stopping force position because {0} is close enough to position {1}", forcedPosition[remoteClient.AgentId], clientAvatar.AbsolutePosition));
+//                    m_log.DebugFormat(
+//                        "[LAND MANAGEMENT MODULE]: Stopping force position of {0} because {1} is close enough to {2}",
+//                        clientAvatar.Name, clientAvatar.AbsolutePosition, forcedPosition[remoteClient.AgentId]);
+
                     forcedPosition.Remove(remoteClient.AgentId);
                 }
                 //if we are far away, teleport
                 else if (Vector3.Distance(clientAvatar.AbsolutePosition, forcedPosition[remoteClient.AgentId]) > 3)
                 {
-                    Debug.WriteLine(string.Format("Teleporting out because {0} is too far from avatar position {1}", forcedPosition[remoteClient.AgentId], clientAvatar.AbsolutePosition));
+                    Vector3 forcePosition = forcedPosition[remoteClient.AgentId];
-                    clientAvatar.Teleport(forcedPosition[remoteClient.AgentId]);
+//                    m_log.DebugFormat(
+//                        "[LAND MANAGEMENT MODULE]: Teleporting out {0} because {1} is too far from avatar position {2}",
+//                        clientAvatar.Name, clientAvatar.AbsolutePosition, forcePosition);
+
+                    m_scene.RequestTeleportLocation(remoteClient, m_scene.RegionInfo.RegionHandle,
+                        forcePosition, clientAvatar.Lookat, (uint)Constants.TeleportFlags.ForceRedirect);
+
                     forcedPosition.Remove(remoteClient.AgentId);
                 }
                 else
                 {
+//                    m_log.DebugFormat(
+//                        "[LAND MANAGEMENT MODULE]: Forcing {0} from {1} to {2}",
+//                        clientAvatar.Name, clientAvatar.AbsolutePosition, forcedPosition[remoteClient.AgentId]);
+
                     //Forces them toward the forced position we want if they aren't there yet
                     agentData.UseClientAgentPosition = true;
                     agentData.ClientAgentPosition = forcedPosition[remoteClient.AgentId];

OpenSim/Region/Framework/Scenes/Scene.cs

@@ -4699,7 +4699,10 @@ namespace OpenSim.Region.Framework.Scenes
                 Vector3? nearestPoint = GetNearestPointInParcelAlongDirectionFromPoint(avatar.AbsolutePosition, dir, nearestParcel);
                 if (nearestPoint != null)
                 {
-                    Debug.WriteLine("Found a sane previous position based on velocity, sending them to: " + nearestPoint.ToString());
+//                    m_log.DebugFormat(
+//                        "[SCENE]: Found a sane previous position based on velocity for {0}, sending them to {1} in {2}",
+//                        avatar.Name, nearestPoint, nearestParcel.LandData.Name);
+
                     return nearestPoint.Value;
                 }
 
@@ -4709,12 +4712,16 @@ namespace OpenSim.Region.Framework.Scenes
                 nearestPoint = GetNearestPointInParcelAlongDirectionFromPoint(avatar.AbsolutePosition, dir, nearestParcel);
                 if (nearestPoint != null)
                 {
-                    Debug.WriteLine("They had a zero velocity, sending them to: " + nearestPoint.ToString());
+//                    m_log.DebugFormat(
+//                        "[SCENE]: {0} had a zero velocity, sending them to {1}", avatar.Name, nearestPoint);
+
                     return nearestPoint.Value;
                 }
 
                 //Ultimate backup if we have no idea where they are
-                Debug.WriteLine("Have no idea where they are, sending them to: " + avatar.lastKnownAllowedPosition.ToString());
+//                m_log.DebugFormat(
+//                    "[SCENE]: No idea where {0} is, sending them to {1}", avatar.Name, avatar.lastKnownAllowedPosition);
+
                 return avatar.lastKnownAllowedPosition;
             }
 
@@ -5120,7 +5127,7 @@ namespace OpenSim.Region.Framework.Scenes
 //                            presence.Name, presence.AbsolutePosition, presence.MoveToPositionTarget);
 
                     Vector3 agent_control_v3 = new Vector3();
-                    presence.HandleMoveToTargetUpdate(ref agent_control_v3);
+                    presence.HandleMoveToTargetUpdate(1, ref agent_control_v3);
                     presence.AddNewMovement(agent_control_v3);
                 }
             }

OpenSim/Region/Framework/Scenes/ScenePresence.cs

@@ -1048,7 +1048,7 @@ namespace OpenSim.Region.Framework.Scenes
         }
 
         /// <summary>
-        ///
+        /// Do not call this directly.  Call Scene.RequestTeleportLocation() instead.
         /// </summary>
         /// <param name="pos"></param>
         public void Teleport(Vector3 pos)
@@ -1522,7 +1522,10 @@ namespace OpenSim.Region.Framework.Scenes
                         }
                         else if (bAllowUpdateMoveToPosition)
                         {
-                            if (HandleMoveToTargetUpdate(ref agent_control_v3))
+                            // The UseClientAgentPosition is set if parcel ban is forcing the avatar to move to a
+                            // certain position.  It's only check for tolerance on returning to that position is 0.2
+                            // rather than 1, at which point it removes its force target.
+                            if (HandleMoveToTargetUpdate(agentData.UseClientAgentPosition ? 0.2 : 1, ref agent_control_v3))
                                 update_movementflag = true;
                         }
                     }
@@ -1584,7 +1587,7 @@ namespace OpenSim.Region.Framework.Scenes
         /// </remarks>
         /// <param value="agent_control_v3">Cumulative agent movement that this method will update.</param>
         /// <returns>True if movement has been updated in some way.  False otherwise.</returns>
-        public bool HandleMoveToTargetUpdate(ref Vector3 agent_control_v3)
+        public bool HandleMoveToTargetUpdate(double tolerance, ref Vector3 agent_control_v3)
         {
 //            m_log.DebugFormat("[SCENE PRESENCE]: Called HandleMoveToTargetUpdate() for {0}", Name);
 
@@ -1601,7 +1604,7 @@ namespace OpenSim.Region.Framework.Scenes
 //                            Name, AbsolutePosition, MoveToPositionTarget, distanceToTarget);
 
             // Check the error term of the current position in relation to the target position
-            if (distanceToTarget <= 1)
+            if (distanceToTarget <= tolerance)
             {
                 // We are close enough to the target
                 AbsolutePosition = MoveToPositionTarget;
@@ -1777,7 +1780,7 @@ namespace OpenSim.Region.Framework.Scenes
 //            m_log.DebugFormat("[SCENE PRESENCE]: Body rot for {0} set to {1}", Name, Rotation);
             
             Vector3 agent_control_v3 = new Vector3();
-            HandleMoveToTargetUpdate(ref agent_control_v3);
+            HandleMoveToTargetUpdate(1, ref agent_control_v3);
             AddNewMovement(agent_control_v3);
         }