From eacacb5989a9ad178694dce8f59767fc9b71ea89 Mon Sep 17 00:00:00 2001
From: Adam Powell <adamp@google.com>
Date: Wed, 23 Mar 2016 13:07:27 -0700
Subject: Fix bugs around restoring nested retained instance fragments

Framework edition

In a few configurations the child fragment state of a
retained-instance fragment would not be preserved correctly, leading
to child fragments not being restored. Clean this up along with live
state management issues that were leading to logged warnings during
normal fragment operation.

Bug 27371492
Bug 27477824

Change-Id: I847ac05b1757392580e008dc20c50c3ef365ca68
---
 core/java/android/app/Fragment.java        | 45 +++++++++++++++++-------------
 core/java/android/app/FragmentManager.java |  9 ++++--
 2 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/core/java/android/app/Fragment.java b/core/java/android/app/Fragment.java
index 6870bbff48c7..f7a4557f8760 100644
--- a/core/java/android/app/Fragment.java
+++ b/core/java/android/app/Fragment.java
@@ -1429,16 +1429,20 @@ public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListene
         final Context context = getContext();
         final int version = context != null ? context.getApplicationInfo().targetSdkVersion : 0;
         if (version >= Build.VERSION_CODES.N) {
-            if (savedInstanceState != null) {
-                Parcelable p = savedInstanceState.getParcelable(Activity.FRAGMENTS_TAG);
-                if (p != null) {
-                    if (mChildFragmentManager == null) {
-                        instantiateChildFragmentManager();
-                    }
-                    mChildFragmentManager.restoreAllState(p, mChildNonConfig);
-                    mChildNonConfig = null;
-                    mChildFragmentManager.dispatchCreate();
+            restoreChildFragmentState(savedInstanceState, true);
+        }
+    }
+
+    void restoreChildFragmentState(@Nullable Bundle savedInstanceState, boolean provideNonConfig) {
+        if (savedInstanceState != null) {
+            Parcelable p = savedInstanceState.getParcelable(Activity.FRAGMENTS_TAG);
+            if (p != null) {
+                if (mChildFragmentManager == null) {
+                    instantiateChildFragmentManager();
                 }
+                mChildFragmentManager.restoreAllState(p, provideNonConfig ? mChildNonConfig : null);
+                mChildNonConfig = null;
+                mChildFragmentManager.dispatchCreate();
             }
         }
     }
@@ -1692,6 +1696,18 @@ public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListene
      */
     public void onDetach() {
         mCalled = true;
+
+        // Destroy the child FragmentManager if we still have it here.
+        // We won't unless we're retaining our instance and if we do,
+        // our child FragmentManager instance state will have already been saved.
+        if (mChildFragmentManager != null) {
+            if (!mRetaining) {
+                throw new IllegalStateException("Child FragmentManager of " + this + " was not "
+                        + " destroyed and this fragment is not retaining instance");
+            }
+            mChildFragmentManager.dispatchDestroy();
+            mChildFragmentManager = null;
+        }
     }
 
     /**
@@ -2252,16 +2268,7 @@ public class Fragment implements ComponentCallbacks2, OnCreateContextMenuListene
         final Context context = getContext();
         final int version = context != null ? context.getApplicationInfo().targetSdkVersion : 0;
         if (version < Build.VERSION_CODES.N) {
-            if (savedInstanceState != null) {
-                Parcelable p = savedInstanceState.getParcelable(Activity.FRAGMENTS_TAG);
-                if (p != null) {
-                    if (mChildFragmentManager == null) {
-                        instantiateChildFragmentManager();
-                    }
-                    mChildFragmentManager.restoreAllState(p, null);
-                    mChildFragmentManager.dispatchCreate();
-                }
-            }
+            restoreChildFragmentState(savedInstanceState, false);
         }
     }
 
diff --git a/core/java/android/app/FragmentManager.java b/core/java/android/app/FragmentManager.java
index 063194310e77..2852baf9c21b 100644
--- a/core/java/android/app/FragmentManager.java
+++ b/core/java/android/app/FragmentManager.java
@@ -941,6 +941,9 @@ final class FragmentManagerImpl extends FragmentManager implements LayoutInflate
 
                     if (!f.mRetaining) {
                         f.performCreate(f.mSavedFragmentState);
+                    } else {
+                        f.restoreChildFragmentState(f.mSavedFragmentState, true);
+                        f.mState = Fragment.CREATED;
                     }
                     f.mRetaining = false;
                     if (f.mFromLayout) {
@@ -1009,6 +1012,9 @@ final class FragmentManagerImpl extends FragmentManager implements LayoutInflate
                         f.mSavedFragmentState = null;
                     }
                 case Fragment.ACTIVITY_CREATED:
+                    if (newState > Fragment.ACTIVITY_CREATED) {
+                        f.mState = Fragment.STOPPED;
+                    }
                 case Fragment.STOPPED:
                     if (newState > Fragment.STOPPED) {
                         if (DEBUG) Log.v(TAG, "moveto STARTED: " + f);
@@ -1108,7 +1114,7 @@ final class FragmentManagerImpl extends FragmentManager implements LayoutInflate
                             if (!f.mRetaining) {
                                 f.performDestroy();
                             } else {
-                                f.mState = Fragment.INITIALIZING;
+                                f.mState = Fragment.CREATED;
                             }
 
                             f.mCalled = false;
@@ -1124,7 +1130,6 @@ final class FragmentManagerImpl extends FragmentManager implements LayoutInflate
                                     f.mHost = null;
                                     f.mParentFragment = null;
                                     f.mFragmentManager = null;
-                                    f.mChildFragmentManager = null;
                                 }
                             }
                         }
-- 
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