From b8c27252c1c65cab64cff4e143c70be6441099c9 Mon Sep 17 00:00:00 2001
From: Melanie <melanie@t-data.com>
Date: Thu, 8 Mar 2012 18:31:58 +0100
Subject: [PATCH] Hold a ref to the prim we're sat on rather than querying
 scene each time the check for significant is carried out. Prevents a deadlock
 condition.

---
 .../Region/Framework/Scenes/ScenePresence.cs  | 59 ++++++++++---------
 1 file changed, 31 insertions(+), 28 deletions(-)

diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 26fa6c0bfa..8a7c06a1d3 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -527,15 +527,8 @@ namespace OpenSim.Region.Framework.Scenes
                     // without the parent rotation applied.
                     if (ParentID != 0)
                     {
-                        SceneObjectPart part = m_scene.GetSceneObjectPart(ParentID);
-                        if (part != null)
-                        {
+                        SceneObjectPart part = ParentPart;
                             return part.AbsolutePosition + (m_pos * part.GetWorldRotation());
-                        }
-                        else
-                        {
-                            return ParentPosition + m_pos;
-                        }
                     }
                 }
                 return m_pos;
@@ -653,6 +646,13 @@ namespace OpenSim.Region.Framework.Scenes
         }
         private UUID m_parentUUID = UUID.Zero;
 
+        public SceneObjectPart ParentPart
+        {
+            get { return m_parentPart; }
+            set { m_parentPart = value; }
+        }
+        private SceneObjectPart m_parentPart = null;
+
         public float Health
         {
             get { return m_health; }
@@ -891,6 +891,7 @@ namespace OpenSim.Region.Framework.Scenes
                         part.SitTargetAvatar = UUID;
                     ParentPosition = part.GetWorldPosition();
                     ParentID = part.LocalId;
+                    ParentPart = part;
                     m_pos = m_prevSitOffset;
                     pos = ParentPosition;
                 }
@@ -1865,37 +1866,35 @@ namespace OpenSim.Region.Framework.Scenes
 
             if (ParentID != 0)
             {
-                SceneObjectPart part = m_scene.GetSceneObjectPart(ParentID);
-                if (part != null)
+                SceneObjectPart part = ParentPart;
+                TaskInventoryDictionary taskIDict = part.TaskInventory;
+                if (taskIDict != null)
                 {
-                    TaskInventoryDictionary taskIDict = part.TaskInventory;
-                    if (taskIDict != null)
+                    lock (taskIDict)
                     {
-                        lock (taskIDict)
+                        foreach (UUID taskID in taskIDict.Keys)
                         {
-                            foreach (UUID taskID in taskIDict.Keys)
-                            {
-                                UnRegisterControlEventsToScript(LocalId, taskID);
-                                taskIDict[taskID].PermsMask &= ~(
-                                    2048 | //PERMISSION_CONTROL_CAMERA
-                                    4); // PERMISSION_TAKE_CONTROLS
-                            }
+                            UnRegisterControlEventsToScript(LocalId, taskID);
+                            taskIDict[taskID].PermsMask &= ~(
+                                2048 | //PERMISSION_CONTROL_CAMERA
+                                4); // PERMISSION_TAKE_CONTROLS
                         }
                     }
-
-                    // Reset sit target.
-                    if (part.SitTargetAvatar == UUID)
-                        part.SitTargetAvatar = UUID.Zero;
-
-                    part.ParentGroup.DeleteAvatar(UUID);
-                    ParentPosition = part.GetWorldPosition();
-                    ControllingClient.SendClearFollowCamProperties(part.ParentUUID);
                 }
 
+                // Reset sit target.
+                if (part.SitTargetAvatar == UUID)
+                    part.SitTargetAvatar = UUID.Zero;
+
+                part.ParentGroup.DeleteAvatar(UUID);
+                ParentPosition = part.GetWorldPosition();
+                ControllingClient.SendClearFollowCamProperties(part.ParentUUID);
+
                 m_pos += ParentPosition + new Vector3(0.0f, 0.0f, 2.0f * m_sitAvatarHeight);
                 ParentPosition = Vector3.Zero;
 
                 ParentID = 0;
+                ParentPart = null;
 
                 if (PhysicsActor == null)
                     AddToPhysicalScene(false);
@@ -2356,6 +2355,10 @@ namespace OpenSim.Region.Framework.Scenes
                 return;
             }
 
+            ParentPart = m_scene.GetSceneObjectPart(m_requestedSitTargetID);
+            if (ParentPart == null)
+                return;
+
             ParentID = m_requestedSitTargetID;
 
             Velocity = Vector3.Zero;