Restore previous client AO behaviour by not allowing them to remove the default animation but continue to allow scripts to do so.

This keeps the fix from http://opensimulator.org/mantis/view.php?id=6327
and fixes the behaviour regression in http://opensimulator.org/mantis/view.php?id=6483
Animations may still exhibit different behaviour if both scripts and clients are adjusting animations.
A change in the behaviour of client AO to not remove all animations may be a better long term approach.

OpenSim/Region/Framework/Scenes/Animation/AnimationSet.cs

@@ -87,13 +87,24 @@ namespace OpenSim.Region.Framework.Scenes.Animation
             return false;
         }
 
-        public bool Remove(UUID animID)
+        /// <summary>
+        /// Remove the specified animation
+        /// </summary>
+        /// <param name='animID'></param>
+        /// <param name='allowNoDefault'>
+        /// If true, then the default animation can be entirely removed. 
+        /// If false, then removing the default animation will reset it to the simulator default (currently STAND).
+        /// </param>
+        public bool Remove(UUID animID, bool allowNoDefault)
         {
             lock (m_animations)
             {
                 if (m_defaultAnimation.AnimID == animID)
                 {
+                    if (allowNoDefault)
                         m_defaultAnimation = new OpenSim.Framework.Animation(UUID.Zero, 1, UUID.Zero);
+                    else
+                        ResetDefaultAnimation();
                 }
                 else if (HasAnimation(animID))
                 {

OpenSim/Region/Framework/Scenes/Animation/ScenePresenceAnimator.cs

@@ -109,14 +109,22 @@ namespace OpenSim.Region.Framework.Scenes.Animation
             AddAnimation(animID, objectID);
         }
 
-        public void RemoveAnimation(UUID animID)
+        /// <summary>
+        /// Remove the specified animation
+        /// </summary>
+        /// <param name='animID'></param>
+        /// <param name='allowNoDefault'>
+        /// If true, then the default animation can be entirely removed. 
+        /// If false, then removing the default animation will reset it to the simulator default (currently STAND).
+        /// </param>
+        public void RemoveAnimation(UUID animID, bool allowNoDefault)
         {
             if (m_scenePresence.IsChildAgent)
                 return;
 
 //            m_log.DebugFormat("[SCENE PRESENCE ANIMATOR]: Removing animation {0} for {1}", animID, m_scenePresence.Name);
 
-            if (m_animations.Remove(animID))
+            if (m_animations.Remove(animID, allowNoDefault))
                 SendAnimPack();
         }
 
@@ -132,7 +140,7 @@ namespace OpenSim.Region.Framework.Scenes.Animation
             if (animID == UUID.Zero)
                 return;
 
-            RemoveAnimation(animID);
+            RemoveAnimation(animID, true);
         }
 
         public void ResetAnimations()

OpenSim/Region/Framework/Scenes/ScenePresence.cs

@@ -2260,7 +2260,7 @@ namespace OpenSim.Region.Framework.Scenes
 
         public void HandleStopAnim(IClientAPI remoteClient, UUID animID)
         {
-            Animator.RemoveAnimation(animID);
+            Animator.RemoveAnimation(animID, false);
         }
 
         /// <summary>

OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs

@@ -3364,7 +3364,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                     if (animID == UUID.Zero)
                         presence.Animator.RemoveAnimation(anim);
                     else
-                        presence.Animator.RemoveAnimation(animID);
+                        presence.Animator.RemoveAnimation(animID, true);
                 }
             }
         }

OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs

@@ -986,7 +986,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
                     if (animID == UUID.Zero)
                         target.Animator.RemoveAnimation(animation);
                     else
-                        target.Animator.RemoveAnimation(animID);
+                        target.Animator.RemoveAnimation(animID, true);
                 }
             }
         }