Special-case backup/restore of replaced settings

Bug: 153940088
Test: atest SettingsProviderTest:SettingsHelperTest

Values for some settings might be changed temporarily. If a backup happens at that moment, we want to backup the real values instead of the temporary ones. If a restore happens at that moment, we don't want to restore values for modified settings. See https://b.corp.google.com/issues/153940088#comment2 for context.

Change-Id: I4866f56376ffa393220bbef828a4b876d586146b
diff --git a/packages/SettingsProvider/Android.bp b/packages/SettingsProvider/Android.bp
index d67bd8d..9d042a4 100644
--- a/packages/SettingsProvider/Android.bp
+++ b/packages/SettingsProvider/Android.bp
@@ -34,6 +34,7 @@
     ],
     static_libs: [
         "androidx.test.rules",
+        "mockito-target-minus-junit4",
         "SettingsLibDisplayDensityUtils",
         "platform-test-annotations",
         "truth-prebuilt",
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsHelper.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsHelper.java
index b6e31d2..d023d98 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsHelper.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsHelper.java
@@ -48,6 +48,8 @@
 public class SettingsHelper {
     private static final String TAG = "SettingsHelper";
     private static final String SILENT_RINGTONE = "_silent";
+    private static final String SETTINGS_REPLACED_KEY = "backup_skip_user_facing_data";
+    private static final String SETTING_ORIGINAL_KEY_SUFFIX = "_original";
     private static final float FLOAT_TOLERANCE = 0.01f;
 
     private Context mContext;
@@ -121,6 +123,10 @@
      */
     public void restoreValue(Context context, ContentResolver cr, ContentValues contentValues,
             Uri destination, String name, String value, int restoredFromSdkInt) {
+        if (isReplacedSystemSetting(name)) {
+            return;
+        }
+
         // Will we need a post-restore broadcast for this element?
         String oldValue = null;
         boolean sendBroadcast = false;
@@ -203,7 +209,32 @@
             }
         }
         // Return the original value
-        return value;
+        return isReplacedSystemSetting(name) ? getRealValueForSystemSetting(name) : value;
+    }
+
+    /**
+     * The setting value might have been replaced temporarily. If that's the case, return the real
+     * value instead of the temporary one.
+     */
+    @VisibleForTesting
+    public String getRealValueForSystemSetting(String setting) {
+        return Settings.System.getString(mContext.getContentResolver(),
+                setting + SETTING_ORIGINAL_KEY_SUFFIX);
+    }
+
+    @VisibleForTesting
+    public boolean isReplacedSystemSetting(String setting) {
+        // This list should not be modified.
+        if (!Settings.System.MASTER_MONO.equals(setting)
+                && !Settings.System.SCREEN_OFF_TIMEOUT.equals(setting)) {
+            return false;
+        }
+        // If this flag is set, values for the system settings from the list above have been
+        // temporarily replaced. We don't want to back up the temporary value or run restore for
+        // such settings.
+        // TODO(154822946): Remove this logic in the next release.
+        return Settings.Secure.getInt(mContext.getContentResolver(), SETTINGS_REPLACED_KEY,
+                /* def */ 0) != 0;
     }
 
     /**
diff --git a/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsHelperTest.java b/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsHelperTest.java
index d112fac..7baa226 100644
--- a/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsHelperTest.java
+++ b/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsHelperTest.java
@@ -18,18 +18,79 @@
 
 import static junit.framework.Assert.assertEquals;
 
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verifyZeroInteractions;
+import static org.mockito.Mockito.when;
+
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.media.AudioManager;
+import android.net.Uri;
 import android.os.LocaleList;
+import android.telephony.TelephonyManager;
 
 import androidx.test.runner.AndroidJUnit4;
 
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
 
 /**
  * Tests for the SettingsHelperTest
  */
 @RunWith(AndroidJUnit4.class)
 public class SettingsHelperTest {
+    private static final String SETTING_KEY = "setting_key";
+    private static final String SETTING_VALUE = "setting_value";
+    private static final String SETTING_REAL_VALUE = "setting_real_value";
+
+    private SettingsHelper mSettingsHelper;
+
+    @Mock private Context mContext;
+    @Mock private ContentResolver mContentResolver;
+    @Mock private AudioManager mAudioManager;
+    @Mock private TelephonyManager mTelephonyManager;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        when(mContext.getSystemService(eq(Context.AUDIO_SERVICE))).thenReturn(mAudioManager);
+        when(mContext.getSystemService(eq(Context.TELEPHONY_SERVICE))).thenReturn(
+                mTelephonyManager);
+
+        mSettingsHelper = spy(new SettingsHelper(mContext));
+    }
+
+    @Test
+    public void testOnBackupValue_settingReplaced_returnsRealValue() {
+        when(mSettingsHelper.isReplacedSystemSetting(eq(SETTING_KEY))).thenReturn(true);
+        doReturn(SETTING_REAL_VALUE).when(mSettingsHelper).getRealValueForSystemSetting(
+                eq(SETTING_KEY));
+
+        assertEquals(SETTING_REAL_VALUE, mSettingsHelper.onBackupValue(SETTING_KEY, SETTING_VALUE));
+    }
+
+    @Test
+    public void testGetRealValue_settingNotReplaced_returnsSameValue() {
+        when(mSettingsHelper.isReplacedSystemSetting(eq(SETTING_KEY))).thenReturn(false);
+
+        assertEquals(SETTING_VALUE, mSettingsHelper.onBackupValue(SETTING_KEY, SETTING_VALUE));
+    }
+
+    @Test
+    public void testRestoreValue_settingReplaced_doesNotRestore() {
+        when(mSettingsHelper.isReplacedSystemSetting(eq(SETTING_KEY))).thenReturn(true);
+        mSettingsHelper.restoreValue(mContext, mContentResolver, new ContentValues(), Uri.EMPTY,
+                SETTING_KEY, SETTING_VALUE, /* restoredFromSdkInt */ 0);
+
+        verifyZeroInteractions(mContentResolver);
+    }
+
     @Test
     public void testResolveLocales() throws Exception {
         // Empty string from backup server