title: Crash with setnextanim?
body: <p>I keep getting the setnextanim crash without a trace to the exact location in my code. Here's the only place I use nextanim :</p>
  
  <pre><code>@Override
      public Animation onCreateAnimation(int transit, boolean enter, int nextAnim) {
          Animation defaultAnimation = super.onCreateAnimation(transit, enter, nextAnim);
  
          if (defaultAnimation == null &amp;&amp; nextAnim != 0) {
              defaultAnimation = AnimationUtils.loadAnimation(getActivity(), nextAnim);
          }
  
          if (defaultAnimation != null) {
              if (getView() != null) {
                  getView().setLayerType(View.LAYER_TYPE_HARDWARE, null);
              }
  
              defaultAnimation.setAnimationListener(new Animation.AnimationListener() {
                  @Override
                  public void onAnimationStart(Animation animation) {
                  }
  
                  public void onAnimationEnd(Animation animation) {
                      if (getView() != null) {
                          getView().setLayerType(View.LAYER_TYPE_NONE, null);
                      }
                  }
  
                  @Override
                  public void onAnimationRepeat(Animation animation) {
                  }
              });
          }
  
          return defaultAnimation;
      }
  </code></pre>
  
  <p>and here's the trace I could find:</p>
  
  <pre><code>FATAL EXCEPTION: main
  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.app.Fragment.setNextAnim(int)' on a null object reference
      at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:765)
      at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580)
      at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367)
      at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322)
      at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2229)
      at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:700)
      at android.os.Handler.handleCallback(Handler.java:751)
      at android.os.Handler.dispatchMessage(Handler.java:95)
      at android.os.Looper.loop(Looper.java:154)
      at android.app.ActivityThread.main(ActivityThread.java:6119)
      at java.lang.reflect.Method.invoke(Native Method)
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
  </code></pre>
  
  <p>Any idea what I am doing wrong that might invoke this crash ? </p>