1 files changed, 24 insertions, 11 deletions

diff --git a/OpenSim/Region/Framework/Scenes/Prioritizer.cs b/OpenSim/Region/Framework/Scenes/Prioritizer.cs
index 272f718..3a3ec2b 100644
--- a/OpenSim/Region/Framework/Scenes/Prioritizer.cs
+++ b/OpenSim/Region/Framework/Scenes/Prioritizer.cs
@@ -140,6 +140,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         private double GetPriorityByFrontBack(IClientAPI client, ISceneEntity entity)
         {
+            if (entity == null) return double.NaN;
             ScenePresence presence = m_scene.GetScenePresence(client.AgentId);
             if (presence != null)
             {
@@ -150,11 +151,16 @@ namespace OpenSim.Region.Framework.Scenes
                 // Use group position for child prims
                 Vector3 entityPos = entity.AbsolutePosition;
                 if (entity is SceneObjectPart)
-                {                                                           
-                    // Can't use Scene.GetGroupByPrim() here, since the entity may have been delete from the scene
-                    // before its scheduled update was triggered
-                    //entityPos = m_scene.GetGroupByPrim(entity.LocalId).AbsolutePosition;
-                    entityPos = ((SceneObjectPart)entity).ParentGroup.AbsolutePosition;                    
+                {
+                    SceneObjectGroup group = m_scene.GetGroupByPrim(entity.LocalId);
+                    if (group == null)
+                    {
+                        entityPos = entity.AbsolutePosition;
+                    }
+                    else
+                    {
+                        entityPos = group.AbsolutePosition;
+                    }
                 }
                 else
                 {
@@ -199,9 +205,9 @@ namespace OpenSim.Region.Framework.Scenes
                     return 0.0;
 
                 // Use group position for child prims
-                Vector3 entityPos = entity.AbsolutePosition;
+                Vector3 entityPos;
                 if (entity is SceneObjectPart)
-                    entityPos = m_scene.GetGroupByPrim(entity.LocalId).AbsolutePosition;
+                    entityPos = ((SceneObjectPart)entity).ParentGroup.AbsolutePosition;
                 else
                     entityPos = entity.AbsolutePosition;
 
@@ -224,12 +230,19 @@ namespace OpenSim.Region.Framework.Scenes
 
                     if (entity is SceneObjectPart)
                     {
-                        PhysicsActor physActor = ((SceneObjectPart)entity).ParentGroup.RootPart.PhysActor;
-                        if (physActor == null || !physActor.IsPhysical)
-                            priority += 100;
-
                         if (((SceneObjectPart)entity).ParentGroup.RootPart.IsAttachment)
+                        {
                             priority = 1.0;
+                        }
+                        else
+                        {
+                            PhysicsActor physActor = ((SceneObjectPart)entity).ParentGroup.RootPart.PhysActor;
+                            if (physActor == null || !physActor.IsPhysical)
+                                priority += 100;
+                        }
+
+                        if (((SceneObjectPart)entity).ParentGroup.RootPart != (SceneObjectPart)entity)
+                            priority +=1;
                     }
                     return priority;
                 }