Fix error on setting anim.name to null.

Assets/Cryville/Crtr/Components/SkinAnimation.cs

@@ -11,9 +11,15 @@ namespace Cryville.Crtr.Components {
 		SkinContext _skinContext;
 
 		AnimationSpan _anim;
+		int _name;
 		public int Name {
 			set {
-				if (value == 0) return;
+				if (_name == value) return;
+				_name = value;
+				if (value == 0) {
+					_anim = null;
+				}
+				else {
 					var id = new Identifier(value);
 					AnimationSpan anim;
 					if (!ChartPlayer.pskin.animations.TryGetValue(id, out anim)) {
@@ -24,6 +30,7 @@ namespace Cryville.Crtr.Components {
 					_anim = anim;
 				}
 			}
+		}
 		public float Duration { get; private set; }
 
 		double _startTime;