Properly restore position on crossing failure for mega-regions.

Fix odd "cannot cross into banned parcel" viewer error message when crossing
into non-existant region. Proper permission failure messages are now returned.

OpenSim/Region/CoreModules/Framework/EntityTransfer/EntityTransferModule.cs

@@ -1443,10 +1443,12 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
         //    see that it is actually outside the current region), find the new region that the
         //    point is actually in.
         // Returns the coordinates and information of the new region or 'null' of it doesn't exist.
-        public GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos, out string version, out Vector3 newpos)
+        public GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos,
+                                            out string version, out Vector3 newpos, out string failureReason)
         {
             version = String.Empty;
             newpos = pos;
+            failureReason = string.Empty;
 
 //            m_log.DebugFormat(
 //                "[ENTITY TRANSFER MODULE]: Crossing agent {0} at pos {1} in {2}", agent.Name, pos, scene.Name);
@@ -1469,6 +1471,7 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
 
                 if (m_bannedRegionCache.IfBanned(neighbourRegion.RegionHandle, agentID))
                 {
+                    failureReason = "Cannot region cross into banned parcel";
                     neighbourRegion = null;
                 }
                 else
@@ -1478,15 +1481,19 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
                 }
 
                 // Check to see if we have access to the target region.
-                string reason;
                 if (neighbourRegion != null
-                    && !scene.SimulationService.QueryAccess(neighbourRegion, agentID, newpos, out version, out reason))
+                    && !scene.SimulationService.QueryAccess(neighbourRegion, agentID, newpos, out version, out failureReason))
                 {
                     // remember banned
                     m_bannedRegionCache.Add(neighbourRegion.RegionHandle, agentID);
                     neighbourRegion = null;
                 }
             }
+            else
+            {
+                // The destination region just doesn't exist
+                failureReason = "Cannot cross into non-existant region";
+            }
 
             if (neighbourRegion == null)
                 m_log.DebugFormat("{0} GetDestination: region not found. Old region name={1} at <{2},{3}> of size <{4},{5}>. Old pos={6}",
@@ -1509,11 +1516,13 @@ namespace OpenSim.Region.CoreModules.Framework.EntityTransfer
             uint y;
             Vector3 newpos;
             string version;
+            string failureReason;
 
-            GridRegion neighbourRegion = GetDestination(agent.Scene, agent.UUID, agent.AbsolutePosition, out version, out newpos);
+            GridRegion neighbourRegion = GetDestination(agent.Scene, agent.UUID, agent.AbsolutePosition,
+                                                            out version, out newpos, out failureReason);
             if (neighbourRegion == null)
             {
-                agent.ControllingClient.SendAlertMessage("Cannot region cross into banned parcel");
+                agent.ControllingClient.SendAlertMessage(failureReason);
                 return false;
             }
 

OpenSim/Region/Framework/Interfaces/IEntityTransferModule.cs

@@ -92,7 +92,8 @@ namespace OpenSim.Region.Framework.Interfaces
 
         void EnableChildAgent(ScenePresence agent, GridRegion region);
 
-        GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos, out string version, out Vector3 newpos);
+        GridRegion GetDestination(Scene scene, UUID agentID, Vector3 pos, out string version,
+                                        out Vector3 newpos, out string reason);
 
         void Cross(SceneObjectGroup sog, Vector3 position, bool silent);
 

OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs

@@ -459,6 +459,7 @@ namespace OpenSim.Region.Framework.Scenes
                         IEntityTransferModule entityTransfer = m_scene.RequestModuleInterface<IEntityTransferModule>();
                         string version = String.Empty;
                         Vector3 newpos = Vector3.Zero;
+                        string failureReason = String.Empty;
                         OpenSim.Services.Interfaces.GridRegion destination = null;
 
                         if (m_rootPart.KeyframeMotion != null)
@@ -476,7 +477,7 @@ namespace OpenSim.Region.Framework.Scenes
 
                             // We set the avatar position as being the object
                             // position to get the region to send to
-                            if ((destination = entityTransfer.GetDestination(m_scene, av.UUID, val, out version, out newpos)) == null)
+                            if ((destination = entityTransfer.GetDestination(m_scene, av.UUID, val, out version, out newpos, out failureReason)) == null)
                             {
                                 canCross = false;
                                 break;

OpenSim/Region/Framework/Scenes/ScenePresence.cs

@@ -3473,8 +3473,6 @@ namespace OpenSim.Region.Framework.Scenes
                 Vector3 pos2 = AbsolutePosition;
                 Vector3 origPosition = pos2;
                 Vector3 vel = Velocity;
-                int neighbor = 0;
-                int[] fix = new int[2];
 
                 // Compute the avatar position in the next physics tick.
                 // If the avatar will be crossing, we force the crossing to happen now
@@ -3507,23 +3505,13 @@ namespace OpenSim.Region.Framework.Scenes
                             if (m_requestedSitTargetUUID == UUID.Zero)
                             {
                                 m_log.DebugFormat("{0} CheckForBorderCrossing: Crossing failed. Restoring old position.", LogHeader);
-                                const float borderFudge = 0.1f;
 
-                                if (origPosition.X < 0)
-                                    origPosition.X = borderFudge;
-                                else if (origPosition.X > (float)m_scene.RegionInfo.RegionSizeX)
-                                    origPosition.X = (float)m_scene.RegionInfo.RegionSizeX - borderFudge;
-                                if (origPosition.Y < 0)
-                                    origPosition.Y = borderFudge;
-                                else if (origPosition.Y > (float)m_scene.RegionInfo.RegionSizeY)
-                                    origPosition.Y = (float)m_scene.RegionInfo.RegionSizeY - borderFudge;
                                 Velocity = Vector3.Zero;
-                                AbsolutePosition = origPosition;
+                                AbsolutePosition = EnforceSanityOnPosition(origPosition);
 
                                 AddToPhysicalScene(isFlying);
                             }
                         }
-                             
                     }
                 }
                 else
@@ -3541,6 +3529,36 @@ namespace OpenSim.Region.Framework.Scenes
             }   
         }
 
+        // Given a position, make sure it is within the current region.
+        // If just outside some border, the returned position will be just inside the border on that side.
+        private Vector3 EnforceSanityOnPosition(Vector3 origPosition)
+        {
+            const float borderFudge = 0.1f;
+            Vector3 ret = origPosition;
+
+            // Sanity checking on the position to make sure it is in the region we couldn't cross from
+            float extentX = (float)m_scene.RegionInfo.RegionSizeX;
+            float extentY = (float)m_scene.RegionInfo.RegionSizeY;
+            IRegionCombinerModule combiner = m_scene.RequestModuleInterface<IRegionCombinerModule>();
+            if (combiner != null)
+            {
+                // If a mega-region, the size could be much bigger
+                Vector2 megaExtent = combiner.GetSizeOfMegaregion(m_scene.RegionInfo.RegionID);
+                extentX = megaExtent.X;
+                extentY = megaExtent.Y;
+            }
+            if (ret.X < 0)
+                ret.X = borderFudge;
+            else if (ret.X >= extentX)
+                ret.X = extentX - borderFudge;
+            if (ret.Y < 0)
+                ret.Y = borderFudge;
+            else if (ret.Y >= extentY)
+                ret.Y = extentY - borderFudge;
+
+            return ret;
+        }
+
         /// <summary>
         /// Moves the agent outside the region bounds
         /// Tells neighbor region that we're crossing to it