am 7071786e: Clear child FragmentManagers when destroying Fragments.

* commit '7071786e0074bea42b01236f817383cab69c1b63':
  Clear child FragmentManagers when destroying Fragments.

core/java/android/app/Fragment.java

@@ -1402,6 +1402,7 @@ public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListene
         mRestored = false;
         mBackStackNesting = 0;
         mFragmentManager = null;
+        mChildFragmentManager = null;
         mActivity = null;
         mFragmentId = 0;
         mContainerId = 0;

core/java/android/app/FragmentManager.java

@@ -1026,6 +1026,7 @@ final class FragmentManagerImpl extends FragmentManager {
                                     f.mActivity = null;
                                     f.mParentFragment = null;
                                     f.mFragmentManager = null;
+                                    f.mChildFragmentManager = null;
                                 }
                             }
                         }