Do not allow a script to attach a prim if its being sat upon.

This prevents a stack overflow where a get position on the avatar will refer to the attachment which will in turn refer back to the avatar.
This required recording of all sitting avatars on a prim which is done separately from recording the sit target avatar.
Recording HashSet is null if there are no sitting avatars in order to save memory.

1 files changed, 17 insertions, 1 deletions

diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index c7a670f..c6a2a03 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -578,6 +578,12 @@ namespace OpenSim.Region.Framework.Scenes
         public uint ParentID { get; set; }
 
         /// <summary>
+        /// Are we sitting on an object?
+        /// </summary>
+        /// <remarks>A more readable way of testing presence sit status than ParentID == 0</remarks>
+        public bool IsSatOnObject { get { return ParentID != 0; } }
+
+        /// <summary>
         /// If the avatar is sitting, the prim that it's sitting on.  If not sitting then null.
         /// </summary>
         /// <remarks>
@@ -1808,6 +1814,8 @@ namespace OpenSim.Region.Framework.Scenes
                 SendAvatarDataToAllAgents();
                 m_requestedSitTargetID = 0;
 
+                part.RemoveSittingAvatar(UUID);
+
                 if (part != null)
                     part.ParentGroup.TriggerScriptChangedEvent(Changed.LINK);
             }
@@ -1887,7 +1895,7 @@ namespace OpenSim.Region.Framework.Scenes
                    )
                    ));
 
-//                m_log.DebugFormat("[SCENE PRESENCE]: {0} {1}", SitTargetisSet, SitTargetUnOccupied);
+            m_log.DebugFormat("[SCENE PRESENCE]: {0} {1}", SitTargetisSet, SitTargetUnOccupied);
 
             if (PhysicsActor != null)
                 m_sitAvatarHeight = PhysicsActor.Size.Z;
@@ -1920,6 +1928,12 @@ namespace OpenSim.Region.Framework.Scenes
                     AbsolutePosition = pos + new Vector3(0.0f, 0.0f, m_sitAvatarHeight);
                     canSit = true;
                 }
+//                else
+//                {
+//                    m_log.DebugFormat(
+//                        "[SCENE PRESENCE]: Ignoring sit request of {0} on {1} {2} because sit target is unset and outside 10m",
+//                        Name, part.Name, part.LocalId);
+//                }
             }
 
             if (canSit)
@@ -1930,6 +1944,8 @@ namespace OpenSim.Region.Framework.Scenes
                     RemoveFromPhysicalScene();
                 }
 
+                part.AddSittingAvatar(UUID);
+
                 cameraAtOffset = part.GetCameraAtOffset();
                 cameraEyeOffset = part.GetCameraEyeOffset();
                 forceMouselook = part.GetForceMouselook();