1 files changed, 25 insertions, 7 deletions

diff --git a/OpenSim/Region/Framework/Scenes/Prioritizer.cs b/OpenSim/Region/Framework/Scenes/Prioritizer.cs
index de3c360..145f9ed 100644
--- a/OpenSim/Region/Framework/Scenes/Prioritizer.cs
+++ b/OpenSim/Region/Framework/Scenes/Prioritizer.cs
@@ -134,6 +134,7 @@ 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)
             {
@@ -144,7 +145,17 @@ namespace OpenSim.Region.Framework.Scenes
                 // Use group position for child prims
                 Vector3 entityPos = entity.AbsolutePosition;
                 if (entity is SceneObjectPart)
-                    entityPos = m_scene.GetGroupByPrim(entity.LocalId).AbsolutePosition;
+                {
+                    SceneObjectGroup group = m_scene.GetGroupByPrim(entity.LocalId);
+                    if (group == null)
+                    {
+                        entityPos = entity.AbsolutePosition;
+                    }
+                    else
+                    {
+                        entityPos = group.AbsolutePosition;
+                    }
+                }
                 else
                     entityPos = entity.AbsolutePosition;
 
@@ -186,9 +197,9 @@ 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;
 
@@ -211,12 +222,19 @@ 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;
                 }