EffectTrack : fixed isssue where an IllegalArgumentExceptio was wrongly raised when removing the spatial from the kill particle control

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9842 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core/com/jme3/animation/EffectTrack.java

@@ -88,11 +88,14 @@ public class EffectTrack implements ClonableTrack {
         @Override
         public void setSpatial(Spatial spatial) {
            super.setSpatial(spatial);
+            if (spatial != null) {
                 if (spatial instanceof ParticleEmitter) {
                     emitter = (ParticleEmitter) spatial;
                 } else {
                     throw new IllegalArgumentException("KillParticleEmitter can only ba attached to ParticleEmitter");
                 }
+            }
+           
             
         }
         
@@ -371,7 +374,7 @@ public class EffectTrack implements ClonableTrack {
         emitter = (ParticleEmitter) in.readSavable("emitter", null);
         emitter.setParticlesPerSec(0);
         //if the emitter was saved with a KillParticleControl we remove it.
-        emitter.removeControl(KillParticleControl.class);
+//        emitter.removeControl(KillParticleControl.class);
         length = in.readFloat("length", length);
         startOffset = in.readFloat("startOffset", 0);
     }