From 4034eaecff7e71f3de95a192c144e9c21e6f5a29 Mon Sep 17 00:00:00 2001
From: George Mount <mount@google.com>
Date: Tue, 16 May 2017 13:07:51 -0700
Subject: [PATCH] Fix broken LoaderLifecycleTest#loaderIdentityTest

Bug 37994415

We have a preemptive check for getLoaderManager() to ensure that
the host is set before returning a value. In this test, the host
was not set because the fragment was restored and on the back stack.

The solution is to pop the back stack to ensure that it is added
so that it comes up to the proper state before getting the loader
manager.

Test: ran the broken test
Change-Id: Ic91cc5ca9468da22bdfef28cda1d4488b2f737f0
---
 .../src/android/app/LoaderLifecycleTest.java  | 22 +++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/core/tests/coretests/src/android/app/LoaderLifecycleTest.java b/core/tests/coretests/src/android/app/LoaderLifecycleTest.java
index 1850d575dfa58..c83e7988dcc64 100644
--- a/core/tests/coretests/src/android/app/LoaderLifecycleTest.java
+++ b/core/tests/coretests/src/android/app/LoaderLifecycleTest.java
@@ -17,6 +17,13 @@
 
 package android.app;
 
+import static junit.framework.TestCase.assertNotNull;
+import static junit.framework.TestCase.assertNotSame;
+import static junit.framework.TestCase.assertSame;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 import android.content.Context;
 import android.os.Handler;
 import android.os.Parcelable;
@@ -24,14 +31,11 @@ import android.support.test.filters.MediumTest;
 import android.support.test.rule.ActivityTestRule;
 import android.support.test.runner.AndroidJUnit4;
 import android.util.ArrayMap;
+
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
-import static junit.framework.TestCase.assertNotNull;
-import static junit.framework.TestCase.assertNotSame;
-import static junit.framework.TestCase.assertSame;
-
 @RunWith(AndroidJUnit4.class)
 public class LoaderLifecycleTest {
     @Rule
@@ -203,6 +207,16 @@ public class LoaderLifecycleTest {
 
             // Test that the fragments are in the configuration we expect
             final Fragment restoredOne = fm2.findFragmentByTag("one");
+            try {
+                restoredOne.getLoaderManager();
+                fail("A restored fragment on the back stack doesn't have a host, so it should "
+                        + "throw an exception");
+            } catch (IllegalStateException e) {
+                // expected
+            }
+            fm2.popBackStackImmediate();
+            // Now restoredOne should be added and should be in a good state.
+            assertTrue(restoredOne.isAdded());
             final LoaderManager lm2 = restoredOne.getLoaderManager();
 
             assertSame("didn't get same LoaderManager instance back", lm2, lm1);