Merge "Check for nullness in WallpaperService onDestroy" into udc-dev

core/java/android/service/wallpaper/WallpaperService.java

@@ -2738,7 +2738,12 @@ public abstract class WallpaperService extends Service {
             engineWrapper.destroy();
         }
         mActiveEngines.clear();
-        mBackgroundThread.quitSafely();
+        if (mBackgroundThread != null) {
+            // onDestroy might be called without a previous onCreate if WallpaperService was
+            // instantiated manually. While this is a misuse of the API, some things break
+            // if here we don't take into consideration this scenario.
+            mBackgroundThread.quitSafely();
+        }
         Trace.endSection();
     }