BulletSim: Fix crash on the destruction of physical linksets.

While fixing the above, add methods to physical body and shape pointer
wrapper so routines won't have to know that IntPtr.Zero means no
physical instance.
Fix problem with physical linksets failing after a few sits and
unsits by properly restoring child prom positions for compound
linksets after multiple selection and deselections.

1 files changed, 2 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 21aa9be..88460cc 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -124,7 +124,9 @@ public sealed class BSCharacter : BSPhysObject
         PhysicsScene.TaintedObject("BSCharacter.destroy", delegate()
         {
             PhysicsScene.Shapes.DereferenceBody(PhysBody, true, null);
+            PhysBody.Clear();
             PhysicsScene.Shapes.DereferenceShape(PhysShape, true, null);
+            PhysShape.Clear();
         });
     }