Merge "Don't let old Launcher activity interfere with new one" into ub-now-porkchop

src/com/android/launcher3/Launcher.java

@@ -1134,7 +1134,9 @@ public class Launcher extends Activity
     @Override
     public Object onRetainNonConfigurationInstance() {
         // Flag the loader to stop early before switching
-        mModel.stopLoader();
+        if (mModel.isCurrentCallbacks(this)) {
+            mModel.stopLoader();
+        }
         if (mAppsCustomizeContent != null) {
             mAppsCustomizeContent.surrender();
         }
@@ -1997,8 +1999,13 @@ public class Launcher extends Activity
 
         // Stop callbacks from LauncherModel
         LauncherAppState app = (LauncherAppState.getInstance());
-        mModel.stopLoader();
-        app.setLauncher(null);
+
+        // It's possible to receive onDestroy after a new Launcher activity has
+        // been created. In this case, don't interfere with the new Launcher.
+        if (mModel.isCurrentCallbacks(this)) {
+            mModel.stopLoader();
+            app.setLauncher(null);
+        }
 
         try {
             mAppWidgetHost.stopListening();

src/com/android/launcher3/LauncherModel.java

@@ -1385,6 +1385,10 @@ public class LauncherModel extends BroadcastReceiver
         return isLaunching;
     }
 
+    public boolean isCurrentCallbacks(Callbacks callbacks) {
+        return (mCallbacks != null && mCallbacks.get() == callbacks);
+    }
+
     public void startLoader(boolean isLaunching, int synchronousBindPage) {
         startLoader(isLaunching, synchronousBindPage, LOADER_FLAG_NONE);
     }