Merge "Don't create a file with empty favorites" into rvc-qpr-dev

packages/SystemUI/src/com/android/systemui/controls/controller/ControlsFavoritePersistenceWrapper.kt

@@ -87,6 +87,10 @@ class ControlsFavoritePersistenceWrapper(
      * @param list a list of favorite controls. The list will be stored in the same order.
      */
     fun storeFavorites(structures: List<StructureInfo>) {
+        if (structures.isEmpty() && !file.exists()) {
+            // Do not create a new file to store nothing
+            return
+        }
         executor.execute {
             Log.d(TAG, "Saving data to file: $file")
             val atomicFile = AtomicFile(file)

packages/SystemUI/tests/src/com/android/systemui/controls/controller/ControlsFavoritePersistenceWrapperTest.kt

@@ -25,6 +25,7 @@ import com.android.systemui.util.concurrency.FakeExecutor
 import com.android.systemui.util.time.FakeSystemClock
 import org.junit.After
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -78,4 +79,15 @@ class ControlsFavoritePersistenceWrapperTest : SysuiTestCase() {
 
         assertEquals(list, wrapper.readFavorites())
     }
+
+    @Test
+    fun testSaveEmptyOnNonExistingFile() {
+        if (file.exists()) {
+            file.delete()
+        }
+
+        wrapper.storeFavorites(emptyList())
+
+        assertFalse(file.exists())
+    }
 }