Make sure the avatar position gets moved along with a prim it is sitting on. This fixes mantis #208 and (maybe) issues with chat and sound coming from the wrong place when sat on a vehicle.

OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs

@@ -469,13 +469,22 @@ namespace OpenSim.Region.Framework.Scenes
                         return;
                     }
                 }
-                foreach (SceneObjectPart part in m_parts.Values)
+                List<SceneObjectPart> parts = new List<SceneObjectPart>(m_parts.Values);
+                lockPartsForRead(false);
+                foreach (SceneObjectPart part in parts)
                 {
                     part.IgnoreUndoUpdate = false;
                     part.StoreUndoState(UndoType.STATE_GROUP_POSITION);
                     part.GroupPosition = val;
                 }
-                lockPartsForRead(false);
+
+                foreach (ScenePresence av in m_linkedAvatars)
+                {
+                    Vector3 offset = m_parts[av.LinkedPrim].GetWorldPosition() - av.ParentPosition;
+                    av.AbsolutePosition += offset;
+                    av.ParentPosition = m_parts[av.LinkedPrim].GetWorldPosition(); //ParentPosition gets cleared by AbsolutePosition
+                    av.SendFullUpdateToAllClients();
+                }
 
                 //if (m_rootPart.PhysActor != null)
                 //{

OpenSim/Region/Framework/Scenes/SceneObjectPart.cs

@@ -682,25 +682,13 @@ namespace OpenSim.Region.Framework.Scenes
 
                         // Tell the physics engines that this prim changed.
                         m_parentGroup.Scene.PhysicsScene.AddPhysicsActorTaint(actor);
+
                     }
                     catch (Exception e)
                     {
                         m_log.Error("[SCENEOBJECTPART]: GROUP POSITION. " + e.Message);
                     }
                 }
-                
-                // TODO if we decide to do sitting in a more SL compatible way (multiple avatars per prim), this has to be fixed, too
-                if (m_sitTargetAvatar != UUID.Zero)
-                {
-                    if (m_parentGroup != null) // TODO can there be a SOP without a SOG?
-                    {
-                        ScenePresence avatar;
-                        if (m_parentGroup.Scene.TryGetScenePresence(m_sitTargetAvatar, out avatar))
-                        {
-                            avatar.ParentPosition = GetWorldPosition();
-                        }
-                    }
-                }
             }
         }
 
@@ -709,6 +697,7 @@ namespace OpenSim.Region.Framework.Scenes
             get { return m_offsetPosition; }
             set
             {
+                Vector3 oldpos = m_offsetPosition;
                 StoreUndoState(UndoType.STATE_PRIM_POSITION);
                 m_offsetPosition = value;
 
@@ -727,11 +716,16 @@ namespace OpenSim.Region.Framework.Scenes
                     List<ScenePresence> avs = ParentGroup.GetLinkedAvatars();
                     foreach (ScenePresence av in avs)
                     {
+                        if (av.LinkedPrim == m_uuid)
+                        {
+                            Vector3 offset = (m_offsetPosition - oldpos);
+                            av.OffsetPosition += offset;
                             av.SendFullUpdateToAllClients();
                         }
                     }
                 }
             }
+        }
 
         public Vector3 RelativePosition
         {

OpenSim/Region/Framework/Scenes/ScenePresence.cs

@@ -595,11 +595,21 @@ namespace OpenSim.Region.Framework.Scenes
 
         private uint m_parentID;
 
+
+        private UUID m_linkedPrim;
+
         public uint ParentID
         {
             get { return m_parentID; }
             set { m_parentID = value; }
         }
+
+        public UUID LinkedPrim
+        {
+            get { return m_linkedPrim; }
+            set { m_linkedPrim = value; }
+        }
+
         public float Health
         {
             get { return m_health; }
@@ -1835,6 +1845,7 @@ namespace OpenSim.Region.Framework.Scenes
                 
 		        m_parentPosition = Vector3.Zero;
 				m_parentID = 0;
+                m_linkedPrim = UUID.Zero;
                 m_offsetRotation = new Quaternion(0.0f, 0.0f, 0.0f, 1.0f);
                 SendFullUpdateToAllClients();
                 m_requestedSitTargetID = 0;
@@ -2422,6 +2433,8 @@ Console.WriteLine("Scripted Sit ofset {0}", m_pos);
                 m_parentID = m_requestedSitTargetID;
             }
 
+            m_linkedPrim = part.UUID;
+
             Velocity = Vector3.Zero;
             RemoveFromPhysicalScene();