Always allow D2D transfers in backup agent

app/src/main/java/com/beemdevelopment/aegis/AegisBackupAgent.java

@@ -18,7 +18,7 @@ import java.io.IOException;
 import java.io.InputStream;
 
 public class AegisBackupAgent extends BackupAgent {
-    private static final String TAG = BackupAgent.class.getSimpleName();
+    private static final String TAG = AegisBackupAgent.class.getSimpleName();
 
     private Preferences _prefs;
 
@@ -34,7 +34,12 @@ public class AegisBackupAgent extends BackupAgent {
                 Build.VERSION.SDK_INT >= Build.VERSION_CODES.P ? data.getTransportFlags() : -1,
                 Build.VERSION.SDK_INT >= Build.VERSION_CODES.O ? data.getQuota() : -1));
 
-        if (!_prefs.isAndroidBackupsEnabled()) {
+        boolean isD2D = Build.VERSION.SDK_INT >= Build.VERSION_CODES.P
+            && (data.getTransportFlags() & FLAG_DEVICE_TO_DEVICE_TRANSFER) == FLAG_DEVICE_TO_DEVICE_TRANSFER;
+
+        if (isD2D) {
+            Log.i(TAG, "onFullBackup(): allowing D2D transfer");
+        } else if (!_prefs.isAndroidBackupsEnabled()) {
             Log.i(TAG, "onFullBackup() skipped: Android backups disabled in preferences");
             return;
         }

app/src/main/res/values/strings.xml

@@ -33,7 +33,7 @@
     <string name="pref_section_import_export_title">Import &amp; Export</string>
     <string name="pref_section_import_export_summary">Import backups of Aegis or other authenticator apps. Create manual exports of your Aegis vault.</string>
     <string name="pref_section_backups_title">Backups</string>
-    <string name="pref_section_backups_summary">Set up automatic backups to a location of your choosing or enable participation in Android\'s backup system.</string>
+    <string name="pref_section_backups_summary">Set up automatic backups to a location of your choosing or enable participation in Android\'s cloud backup system.</string>
     <string name="pref_section_icon_packs">Icon packs</string>
     <string name="pref_section_icon_packs_summary">Manage and import icon packs</string>
     <string name="pref_select_theme_title">Theme</string>
@@ -49,8 +49,9 @@
     <string name="pref_slots_summary">Manage the list of keys that can decrypt the vault</string>
     <string name="pref_import_file_title">Import from file</string>
     <string name="pref_import_file_summary">Import tokens from a file</string>
-    <string name="pref_android_backups_title">Participate in Android\'s backup system</string>
-    <string name="pref_android_backups_summary">Allow Android\'s backup system to include Aegis\' vault in its backups. This is only supported for encrypted vaults.</string>
+    <string name="pref_android_backups_title">Android cloud backups</string>
+    <string name="pref_android_backups_summary">Allow Android\'s cloud backup system to include Aegis\' vault in its backups. This is only supported for encrypted vaults.</string>
+    <string name="pref_android_backups_hint"><i>Device-to-device (D2D) backups are always allowed, regardless of the setting above</i></string>
     <string name="pref_backups_title">Automatically back up the vault</string>
     <string name="pref_backups_summary">Automatically create backups of the vault on external storage when changes are made. This is only supported for encrypted vaults.</string>
     <string name="pref_backups_location_title">Directory for backup files</string>

app/src/main/res/xml/preferences_backups.xml

@@ -35,5 +35,9 @@
             android:title="@string/pref_android_backups_title"
             android:summary="@string/pref_android_backups_summary"
             app:iconSpaceReserved="false"/>
+        <Preference
+            android:selectable="false"
+            android:summary="@string/pref_android_backups_hint"
+            app:iconSpaceReserved="false"/>
     </PreferenceCategory>
 </PreferenceScreen>