3 files changed, 80 insertions, 37 deletions

diff --git a/OpenSim/Region/Environment/Scenes/Scene.cs b/OpenSim/Region/Environment/Scenes/Scene.cs
index d8ce3f0..9c2dd06 100644
--- a/OpenSim/Region/Environment/Scenes/Scene.cs
+++ b/OpenSim/Region/Environment/Scenes/Scene.cs
@@ -1871,13 +1871,14 @@ namespace OpenSim.Region.Environment.Scenes
         }
 
         /// <summary>
-        /// Locate New region Handle and offset the prim position for the new region
-        ///
+        /// Move the given scene object into a new region depending on which region its absolute position has moved 
+        /// into. 
+        /// 
+        /// This method locates the new region handle and offsets the prim position for the new region
         /// </summary>
-        /// <param name="position">current position of Group</param>
-        /// <param name="grp">Scene Object Group that we're crossing</param>
-
-        public void CrossPrimGroupIntoNewRegion(Vector3 position, SceneObjectGroup grp)
+        /// <param name="attemptedPosition">the attempted out of region position of the scene object</param>
+        /// <param name="grp">the scene object that we're crossing</param>
+        public void CrossPrimGroupIntoNewRegion(Vector3 attemptedPosition, SceneObjectGroup grp)
         {
             if (grp == null)
                 return;
@@ -1897,53 +1898,70 @@ namespace OpenSim.Region.Environment.Scenes
                 }
                 return;
             }
-
-            m_log.Warn("Prim crossing: " + grp.ToString());
+            
             int thisx = (int)RegionInfo.RegionLocX;
             int thisy = (int)RegionInfo.RegionLocY;
 
             ulong newRegionHandle = 0;
-            Vector3 pos = position;
+            Vector3 pos = attemptedPosition;
 
-            if (position.X > Constants.RegionSize + 0.1f)
+            if (attemptedPosition.X > Constants.RegionSize + 0.1f)
             {
                 pos.X = ((pos.X - Constants.RegionSize));
-                newRegionHandle = Util.UIntsToLong((uint)((thisx + 1) * Constants.RegionSize), (uint)(thisy * Constants.RegionSize));
+                newRegionHandle 
+                    = Util.UIntsToLong((uint)((thisx + 1) * Constants.RegionSize), (uint)(thisy * Constants.RegionSize));
                 // x + 1
             }
-            else if (position.X < -0.1f)
+            else if (attemptedPosition.X < -0.1f)
             {
                 pos.X = ((pos.X + Constants.RegionSize));
-                newRegionHandle = Util.UIntsToLong((uint)((thisx - 1) * Constants.RegionSize), (uint)(thisy * Constants.RegionSize));
+                newRegionHandle 
+                    = Util.UIntsToLong((uint)((thisx - 1) * Constants.RegionSize), (uint)(thisy * Constants.RegionSize));
                 // x - 1
             }
 
-            if (position.Y > Constants.RegionSize + 0.1f)
+            if (attemptedPosition.Y > Constants.RegionSize + 0.1f)
             {
                 pos.Y = ((pos.Y - Constants.RegionSize));
-                newRegionHandle = Util.UIntsToLong((uint)(thisx * Constants.RegionSize), (uint)((thisy + 1) * Constants.RegionSize));
+                newRegionHandle 
+                    = Util.UIntsToLong((uint)(thisx * Constants.RegionSize), (uint)((thisy + 1) * Constants.RegionSize));
                 // y + 1
             }
-            else if (position.Y < -1f)
+            else if (attemptedPosition.Y < -1f)
             {
                 pos.Y = ((pos.Y + Constants.RegionSize));
-                newRegionHandle = Util.UIntsToLong((uint)(thisx * Constants.RegionSize), (uint)((thisy - 1) * Constants.RegionSize));
+                newRegionHandle 
+                    = Util.UIntsToLong((uint)(thisx * Constants.RegionSize), (uint)((thisy - 1) * Constants.RegionSize));
                 // y - 1
             }
 
             // Offset the positions for the new region across the border
+            Vector3 oldGroupPosition = grp.RootPart.GroupPosition;
             grp.OffsetForNewRegion(pos);
 
-            CrossPrimGroupIntoNewRegion(newRegionHandle, grp);
+            // If we fail to cross the border, then reset the position of the scene object on that border.
+            if (!CrossPrimGroupIntoNewRegion(newRegionHandle, grp))
+            {   
+                grp.OffsetForNewRegion(oldGroupPosition);                
+            }
         }
 
-        public void CrossPrimGroupIntoNewRegion(ulong newRegionHandle, SceneObjectGroup grp)
+        /// <summary>
+        /// Move the given scene object into a new region
+        /// </summary>
+        /// <param name="newRegionHandle"></param>
+        /// <param name="grp">Scene Object Group that we're crossing</param> 
+        /// <returns>
+        /// true if the crossing itself was successful, false on failure
+        /// FIMXE: we still return true if the crossing object was not successfully deleted from the originating region
+        /// </returns>
+        public bool CrossPrimGroupIntoNewRegion(ulong newRegionHandle, SceneObjectGroup grp)
         {
+            bool successYN = false;            
             int primcrossingXMLmethod = 0;
+            
             if (newRegionHandle != 0)
             {
-                bool successYN = false;
-
                 successYN
                     = m_sceneGridService.PrimCrossToNeighboringRegion(
                         newRegionHandle, grp.UUID, m_serialiser.SaveGroupToXml2(grp), primcrossingXMLmethod);
@@ -1955,14 +1973,15 @@ namespace OpenSim.Region.Environment.Scenes
                     {
                         DeleteSceneObject(grp);
                     }
-                    catch (Exception)
+                    catch (Exception e)
                     {
-                        m_log.Warn("[DATABASE]: exception when trying to remove the prim that crossed the border.");
+                        m_log.ErrorFormat(
+                            "[INTERREGION]: Exception deleting the old object left behind on a border crossing for {0}, {1}", 
+                            grp, e);
                     }
                 }
                 else
                 {
-                    m_log.Warn("[INTERREGION]: Prim Crossing Failed!");
                     if (grp.RootPart != null)
                     {
                         if (grp.RootPart.PhysActor != null)
@@ -1970,10 +1989,26 @@ namespace OpenSim.Region.Environment.Scenes
                             grp.RootPart.PhysActor.CrossingFailure();
                         }
                     }
+                    
+                    m_log.ErrorFormat("[INTERREGION]: Prim crossing failed for {0}", grp);
                 }
             }
+            else
+            {
+                m_log.Error("[INTERREGION]: region handle was unexpectedly 0 in Scene.CrossPrimGroupIntoNewRegion()");
+            }
+            
+            return successYN;
         }
 
+        /// <summary>
+        /// Handle a scene object that is crossing into this region from another.
+        /// </summary>
+        /// <param name="regionHandle"></param>
+        /// <param name="primID"></param>
+        /// <param name="objXMLData"></param>
+        /// <param name="XMLMethod"></param>
+        /// <returns></returns>
         public bool IncomingInterRegionPrimGroup(ulong regionHandle, UUID primID, string objXMLData, int XMLMethod)
         {
             m_log.Warn("{[INTERREGION]: A new prim arrived from a neighbor");
diff --git a/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs
index 1b2ea8e..f52e764 100644
--- a/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Environment/Scenes/SceneObjectGroup.cs
@@ -180,6 +180,9 @@ namespace OpenSim.Region.Environment.Scenes
             }
         }
 
+        /// <summary>
+        /// The absolute position of this scene object in the scene
+        /// </summary>
         public override Vector3 AbsolutePosition
         {
             get
@@ -195,8 +198,9 @@ namespace OpenSim.Region.Environment.Scenes
             set
             {
                 Vector3 val = value;
+                
                 if ((val.X > 257f || val.X < -1f || val.Y > 257f || val.Y < -1f) && !m_rootPart.IsAttachment)
-                {
+                {                                       
                     m_scene.CrossPrimGroupIntoNewRegion(val, this);
                 }
 
@@ -899,7 +903,6 @@ namespace OpenSim.Region.Environment.Scenes
         public void ResetChildPrimPhysicsPositions()
         {
             AbsolutePosition = AbsolutePosition; // could someone in the know please explain how this works?
-            //HasGroupChanged = false;
         }
 
         public UUID GetPartsFullID(uint localID)
@@ -1090,10 +1093,10 @@ namespace OpenSim.Region.Environment.Scenes
                         {
                             part.ApplyPhysics(m_rootPart.GetEffectiveObjectFlags(), m_physicalPrim);
                         }
-
+                        
                         // Hack to get the physics scene geometries in the right spot
-                        ResetChildPrimPhysicsPositions();
-                    }
+                        ResetChildPrimPhysicsPositions();                           
+                    }                                         
                 }
                 else
                 {
@@ -2706,5 +2709,10 @@ namespace OpenSim.Region.Environment.Scenes
                 part.TriggerScriptChangedEvent(val);
             }
         }
+        
+        public override string ToString()
+        {
+            return String.Format("{0} {1} ({2})", Name, UUID, AbsolutePosition);
+        }
     }
 }
diff --git a/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs b/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs
index eaabdd5..2b0ad12 100644
--- a/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Environment/Scenes/SceneObjectPart.cs
@@ -108,8 +108,6 @@ namespace OpenSim.Region.Environment.Scenes
         [XmlIgnore]
         public PhysicsActor PhysActor = null;
 
-
-
         //Xantor 20080528 Sound stuff:
         //  Note: This isn't persisted in the database right now, as the fields for that aren't just there yet.
         //        Not a big problem as long as the script that sets it remains in the prim on startup.
@@ -443,6 +441,9 @@ namespace OpenSim.Region.Environment.Scenes
             set { m_particleSystem = value; }
         }
 
+        /// <summary>
+        /// The position of the entire group that this prim belongs to.
+        /// </summary>
         public Vector3 GroupPosition
         {
             get
@@ -475,18 +476,14 @@ namespace OpenSim.Region.Environment.Scenes
                 {
                     try
                     {
-
                         // Root prim actually goes at Position
                         if (_parentID == 0)
                         {
                             PhysActor.Position = new PhysicsVector(value.X, value.Y, value.Z);
-
                         }
                         else
                         {
-
                             // To move the child prim in respect to the group position and rotation we have to calculate
-
                             Vector3 resultingposition = GetWorldPosition();
                             PhysActor.Position = new PhysicsVector(resultingposition.X, resultingposition.Y, resultingposition.Z);
                             Quaternion resultingrot = GetWorldRotation();
@@ -783,8 +780,6 @@ namespace OpenSim.Region.Environment.Scenes
             get { return m_parentGroup; }
         }
 
-
-
         public scriptEvents ScriptEvents
         {
             get { return AggregateScriptEvents; }
@@ -3321,6 +3316,11 @@ namespace OpenSim.Region.Environment.Scenes
         public bool GetForceMouselook() {
             return m_forceMouselook;
         }
+        
+        public override string ToString()
+        {
+            return String.Format("{0} {1} (parent {2}))", Name, UUID, ParentGroup);
+        }        
 
         #endregion Public Methods
     }