K2GO-384 feat(backup): real cancel + clean up the incomplete file

controller/app/src/main/java/org/appdevforall/k2go/backup/domain/BackupEngine.java

@@ -26,6 +26,7 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.zip.GZIPOutputStream;
 
 public final class BackupEngine {
@@ -63,10 +64,13 @@ public static String suggestedFileName(Context ctx) {
      * (over {@code dest}), so the bytes tar produces are observable and metered against the tree's total size
      * ({@code du -sb}). Byte progress tracks the gzip+write time far better than a member count, which
      * front-loads on the many small files and then stalls on the few large ones. When {@code listener} is
-     * null or the pre-count fails, it streams without progress (indeterminate). This Java loop is also the
-     * seam a later backup-cancel interrupts.
+     * null or the pre-count fails, it streams without progress (indeterminate).
+     *
+     * <p>K2GO-384: {@code cancelled} (may be null) aborts the stream — the read loop kills tar and stops. The
+     * caller distinguishes a cancel from a failure by that same flag and removes the incomplete SAF file.
      */
-    public static boolean streamBackup(Context ctx, OutputStream dest, ProgressListener listener) {
+    public static boolean streamBackup(Context ctx, OutputStream dest, ProgressListener listener,
+                                       AtomicBoolean cancelled) {
         File iiabRootDir = new File(ctx.getFilesDir(), "rootfs");
         File nativeDir = new File(ctx.getApplicationInfo().nativeLibraryDir);
         File staticTar = new File(nativeDir, "libtar.so");
@@ -126,6 +130,8 @@ public static boolean streamBackup(Context ctx, OutputStream dest, ProgressListe
                 final long startNs = System.nanoTime();
                 int n;
                 while ((n = in.read(buf)) > 0) {
+                    // K2GO-384: cancel stops tar mid-stream (backup is read-only, so this is always safe).
+                    if (cancelled != null && cancelled.get()) { p.destroy(); break; }
                     gz.write(buf, 0, n);
                     processed += n;
                     if (listener != null && totalBytes > 0L) {
@@ -143,9 +149,10 @@ public static boolean streamBackup(Context ctx, OutputStream dest, ProgressListe
             int exit = p.waitFor();
             if (errDrain != null) { try { errDrain.join(1500); } catch (InterruptedException ignored) { } }
             String tail; synchronized (errTail) { tail = errTail.toString().trim(); }
-            if (exit != 0) {
+            final boolean userCancelled = cancelled != null && cancelled.get();
+            if (exit != 0 && !userCancelled) {   // a cancel kills tar (non-zero) on purpose -- not a failure to log
                 Log.w(TAG, "backup tar exited " + exit + (tail.isEmpty() ? "" : "; stderr tail:\n" + tail));
-            } else if (!tail.isEmpty()) {
+            } else if (exit == 0 && !tail.isEmpty()) {
                 // K2GO-384: succeeded, but --ignore-failed-read let tar skip unreadable entries. Expected ones
                 // are proot mount stubs (iiab/sdcard, ...); RECORD them so a genuinely dropped file is never
                 // silent (the honesty this slice restored -- the old tar|gzip pipe masked all of this).

controller/app/src/main/java/org/appdevforall/k2go/deepop/DeepOpService.java

@@ -106,6 +106,9 @@ public final class DeepOpService extends Service {
      *  pass outcome (complete / error / cancelled / held). Guards the re-callable attemptVerifyAndExtract so a
      *  "Keep restoring" cannot start a second pass over the same temp while one is running. */
     private volatile boolean passRunning = false;
+    /** K2GO-384: cancel for the (read-only, single-pass) BACKUP. streamBackup's read loop reads it and kills
+     *  tar. Always safe (nothing on the device is touched); the terminal removes the incomplete SAF file. */
+    private final java.util.concurrent.atomic.AtomicBoolean backupCancelled = new java.util.concurrent.atomic.AtomicBoolean(false);
     /** K2GO-384: true while the user is deciding on a paused COPY (Cancel pressed). The copy loop blocks on
      *  it; ACTION_RESUME clears it (continue), ACTION_CANCEL_CONFIRM sets cancelBeforeExtract and clears it
      *  (abort). Only the copy is pausable -- verify/extract are external tar processes. */
@@ -201,25 +204,44 @@ public int onStartCommand(Intent intent, int flags, int startId) {
     // ---- BACKUP (read-only) ----
     private void runBackup(final String uriStr) {
         if (done) return;
+        currentCancelKind = DeepOpState.CancelKind.CANCELLABLE;   // K2GO-384: backup is cancellable throughout (read-only)
         setStep(getString(R.string.k2go_br_status_backing), -1);
         AppExecutors.get().io().execute(() -> {
             boolean ok;
             try (OutputStream os = getContentResolver().openOutputStream(Uri.parse(uriStr))) {
                 // K2GO-384: byte-accurate progress + ETA; streamBackup reports from its tar-stdout read loop.
-                // post() is thread-safe and carries cancelKind=NONE (backup's Cancel stays on the notification,
-                // so no on-screen Cancel appears).
+                // post() is thread-safe. backupCancelled lets the on-screen (or notification) Cancel stop tar.
                 ok = os != null && BackupEngine.streamBackup(this, os,
-                        (percent, etaSeconds) -> post(getString(R.string.k2go_br_status_backing), percent, etaSeconds));
+                        (percent, etaSeconds) -> post(getString(R.string.k2go_br_status_backing), percent, etaSeconds),
+                        backupCancelled);
             } catch (Exception e) {
                 Log.e(TAG, "backup failed", e);
                 ok = false;
             }
             final boolean success = ok;
-            main.post(() -> finishJob(success,
-                    getString(R.string.k2go_br_backup_done), getString(R.string.k2go_br_backup_failed)));
+            main.post(() -> {
+                if (done) return;
+                if (!success) {
+                    // K2GO-384: an unfinished backup left an incomplete/damaged .tar.gz at the SAF destination.
+                    // Removing it is the default (no prompt) -- a partial gzip'd tar is useless and unresumable.
+                    deleteBackupDoc(uriStr);
+                    if (backupCancelled.get()) { finishCancelled(); return; }   // user cancel -> bifurcation
+                }
+                finishJob(success, getString(R.string.k2go_br_backup_done), getString(R.string.k2go_br_backup_failed));
+            });
         });
     }
 
+    /** K2GO-384: remove the incomplete/damaged backup file a cancelled or failed run left at the SAF
+     *  destination. Best-effort -- a document picked via CREATE_DOCUMENT supports delete; if not, leave it. */
+    private void deleteBackupDoc(String uriStr) {
+        try {
+            android.provider.DocumentsContract.deleteDocument(getContentResolver(), Uri.parse(uriStr));
+        } catch (Exception e) {
+            Log.w(TAG, "could not delete incomplete backup doc: " + e.getMessage());
+        }
+    }
+
     // ---- RESTORE (destructive) ----
 
     /**
@@ -550,13 +572,14 @@ private void finishCancelled() {
     }
 
     /**
-     * Notification "Cancel" — offered only for BACKUP (read-only, safe to abandon). Restore has no
-     * Cancel action (destructive, hard gate). The in-flight backup stream sees {@code done} and no-ops
-     * on completion. Runs the same cleanup as a failure so the lock is released and the op ends.
+     * Cancel (from the on-screen button's confirm, or the notification action — BACKUP only). Restore has no
+     * Cancel action here (it takes the CANCELLABLE hold / DESTRUCTIVE force-cancel paths below).
      */
     private void cancel() {
         if (owner == EnvironmentLock.Owner.BACKUP) {
-            finishJob(false, "", getString(R.string.k2go_br_backup_failed));
+            // K2GO-384: stop the backup for real -- the read loop sees this, kills tar, and the terminal
+            // removes the incomplete file (was: mark done + FAILED, which left tar running and the file behind).
+            backupCancelled.set(true);
             return;
         }
         // K2GO-384: a Cancel on any pre-destructive pass (CANCELLABLE) HOLDS the run and waits for the

controller/app/src/main/java/org/appdevforall/k2go/redesign/BackupJobFragment.java

@@ -299,6 +299,9 @@ private void setStatusAnimated(String text) {
      */
     private void onCancelTapped() {
         if (!isAdded()) return;
+        // K2GO-384: backup is read-only + single-pass, so its cancel is trivially safe -- a light guard dialog
+        // (against an accidental tap), then stop tar + remove the incomplete file. No hold/pause, no phases.
+        if (!isRestore()) { showBackupCancelDialog(); return; }
         if (lastCancelKind == DeepOpState.CancelKind.DESTRUCTIVE) { showDestructiveCancelDialog(); return; }
         if (lastCancelKind != DeepOpState.CancelKind.CANCELLABLE) return;
         sendToService(DeepOpService.ACTION_CANCEL);   // hold the run while the user decides (no race)
@@ -323,6 +326,23 @@ private void sendToService(String action) {
                 new android.content.Intent(requireContext(), DeepOpService.class).setAction(action));
     }
 
+    /**
+     * K2GO-384: backup is read-only, so cancelling is always safe -- this dialog only guards an accidental tap.
+     * Confirming stops the backup and removes the incomplete file (the default; a partial archive is useless).
+     * Cancelable: nothing is paused, so a scrim/Back dismiss simply keeps the backup running.
+     */
+    private void showBackupCancelDialog() {
+        new BrandDialog(requireContext())
+                .setTitle(getString(R.string.k2go_br_cancel_backup_title))
+                .setMessage(getString(R.string.k2go_br_cancel_backup_body))
+                .setPositive(R.string.k2go_br_cancel_backup_confirm, () -> {
+                    if (cancel != null) cancel.setEnabled(false);
+                    sendToService(DeepOpService.ACTION_CANCEL);   // stop tar -> incomplete file removed -> CANCELLED
+                })
+                .setNegative(R.string.k2go_br_cancel_backup_keep, null)   // dismiss = keep backing up
+                .show();
+    }
+
     /**
      * K2GO-384: cancelling DURING the extract is destructive -- the rootfs is being overwritten. A strong
      * M3 dialog: RED confirm (colorError) gated by an acknowledgement checkbox. Confirming force-cancels the

controller/app/src/main/res/values-ar/strings.xml

@@ -646,6 +646,10 @@
     <string name="k2go_br_cancel_extract_ack">أفهم أن الإلغاء الآن قد يترك نظامي تالفًا أو غير قابل للاستخدام.</string>
     <string name="k2go_br_restore_damaged">تم إلغاء الاستعادة. سيبدأ نظامك في وضع الاسترداد عند التشغيل التالي.</string>
     <string name="k2go_br_cancel_extract_need_ack">حدد المربع لتأكيد فهمك.</string>
+    <string name="k2go_br_cancel_backup_title">إلغاء النسخة الاحتياطية؟</string>
+    <string name="k2go_br_cancel_backup_body">لم تكتمل هذه النسخة الاحتياطية. يؤدي الإلغاء إلى إزالة الملف غير المكتمل — يمكنك بدء نسخة احتياطية جديدة في أي وقت.</string>
+    <string name="k2go_br_cancel_backup_confirm">إلغاء النسخة الاحتياطية</string>
+    <string name="k2go_br_cancel_backup_keep">متابعة النسخ الاحتياطي</string>
     <string name="k2go_br_restore_unreadable">تعذّرت قراءة الملف المحدد، لذا لم يتغيّر أي شيء.</string>
     <string name="deepop_channel_name">النسخ الاحتياطي والاستعادة</string>
     <string name="deepop_channel_desc">يُبقي عملية نسخ احتياطي أو استعادة قيد التشغيل بأمان في الخلفية</string>

controller/app/src/main/res/values-az/strings.xml

@@ -666,6 +666,10 @@
     <string name="k2go_br_cancel_extract_ack">İndi ləğv etməyin sistemimi zədələnmiş və ya yararsız qoya biləcəyini başa düşürəm.</string>
     <string name="k2go_br_restore_damaged">Bərpa ləğv edildi. Sisteminiz növbəti işə salınmada bərpa rejimində başlayacaq.</string>
     <string name="k2go_br_cancel_extract_need_ack">Başa düşdüyünüzü təsdiqləmək üçün qutunu işarələyin.</string>
+    <string name="k2go_br_cancel_backup_title">Ehtiyat nüsxə ləğv edilsin?</string>
+    <string name="k2go_br_cancel_backup_body">Bu ehtiyat nüsxə tamamlanmayıb. Ləğv etmək yarımçıq faylı silir — istənilən vaxt yeni ehtiyat nüsxə başlada bilərsiniz.</string>
+    <string name="k2go_br_cancel_backup_confirm">Ehtiyat nüsxəni ləğv et</string>
+    <string name="k2go_br_cancel_backup_keep">Ehtiyatlamağa davam et</string>
     <string name="k2go_br_restore_unreadable">Seçilmiş fayl oxuna bilmədi, ona görə heç nə dəyişdirilmədi.</string>
     <string name="deepop_channel_name">Ehtiyat nüsxə &amp; bərpa</string>
     <string name="deepop_channel_desc">Ehtiyat nüsxə və ya bərpanı arxa planda təhlükəsiz işlədir</string>

controller/app/src/main/res/values-bg/strings.xml

@@ -653,6 +653,10 @@
     <string name="k2go_br_cancel_extract_ack">Разбирам, че отказът сега може да остави системата ми повредена или неизползваема.</string>
     <string name="k2go_br_restore_damaged">Възстановяването е отказано. Системата ви ще стартира в режим на възстановяване при следващото стартиране.</string>
     <string name="k2go_br_cancel_extract_need_ack">Отметнете полето, за да потвърдите, че разбирате.</string>
+    <string name="k2go_br_cancel_backup_title">Отказ от резервното копие?</string>
+    <string name="k2go_br_cancel_backup_body">Това резервно копие не е завършено. Отказът премахва незавършения файл — можете да започнете ново резервно копие по всяко време.</string>
+    <string name="k2go_br_cancel_backup_confirm">Отказ от резервното копие</string>
+    <string name="k2go_br_cancel_backup_keep">Продължи архивирането</string>
     <string name="k2go_br_restore_unreadable">Избраният файл не можа да бъде прочетен, затова нищо не беше променено.</string>
     <string name="deepop_channel_name">Резервно копие и възстановяване</string>
     <string name="deepop_channel_desc">Поддържа безопасното изпълнение на резервно копие или възстановяване във фонов режим</string>

controller/app/src/main/res/values-bn/strings.xml

@@ -659,6 +659,10 @@
     <string name="k2go_br_cancel_extract_ack">আমি বুঝি যে এখন বাতিল করলে আমার সিস্টেম ক্ষতিগ্রস্ত বা ব্যবহারের অযোগ্য হয়ে যেতে পারে।</string>
     <string name="k2go_br_restore_damaged">পুনরুদ্ধার বাতিল করা হয়েছে। পরবর্তী চালুতে আপনার সিস্টেম রিকভারি মোডে শুরু হবে।</string>
     <string name="k2go_br_cancel_extract_need_ack">আপনি বুঝেছেন তা নিশ্চিত করতে বাক্সটি চেক করুন।</string>
+    <string name="k2go_br_cancel_backup_title">ব্যাকআপ বাতিল করবেন?</string>
+    <string name="k2go_br_cancel_backup_body">এই ব্যাকআপ শেষ হয়নি। বাতিল করলে অসম্পূর্ণ ফাইলটি সরানো হবে — আপনি যেকোনো সময় নতুন ব্যাকআপ শুরু করতে পারেন।</string>
+    <string name="k2go_br_cancel_backup_confirm">ব্যাকআপ বাতিল করুন</string>
+    <string name="k2go_br_cancel_backup_keep">ব্যাকআপ চালিয়ে যান</string>
     <string name="k2go_br_restore_unreadable">নির্বাচিত ফাইলটি পড়া যায়নি, তাই কিছুই পরিবর্তন করা হয়নি।</string>
     <string name="deepop_channel_name">ব্যাকআপ ও পুনরুদ্ধার</string>
     <string name="deepop_channel_desc">ব্যাকআপ বা পুনরুদ্ধার ব্যাকগ্রাউন্ডে নিরাপদে চালু রাখে</string>

controller/app/src/main/res/values-cs/strings.xml

@@ -653,6 +653,10 @@
     <string name="k2go_br_cancel_extract_ack">Rozumím, že zrušení nyní může můj systém poškodit nebo učinit nepoužitelným.</string>
     <string name="k2go_br_restore_damaged">Obnovení zrušeno. Váš systém se při příštím spuštění spustí v režimu obnovy.</string>
     <string name="k2go_br_cancel_extract_need_ack">Zaškrtnutím políčka potvrďte, že rozumíte.</string>
+    <string name="k2go_br_cancel_backup_title">Zrušit zálohu?</string>
+    <string name="k2go_br_cancel_backup_body">Tato záloha není dokončena. Zrušením se odstraní neúplný soubor — novou zálohu můžete kdykoli spustit.</string>
+    <string name="k2go_br_cancel_backup_confirm">Zrušit zálohu</string>
+    <string name="k2go_br_cancel_backup_keep">Pokračovat v zálohování</string>
     <string name="k2go_br_restore_unreadable">Vybraný soubor se nepodařilo přečíst, takže se nic nezměnilo.</string>
     <string name="deepop_channel_name">Záloha &amp; obnova</string>
     <string name="deepop_channel_desc">Udržuje zálohu nebo obnovu bezpečně spuštěnou na pozadí</string>

controller/app/src/main/res/values-de/strings.xml

@@ -646,6 +646,10 @@
     <string name="k2go_br_cancel_extract_ack">Ich verstehe, dass ein Abbruch jetzt mein System beschädigen oder unbrauchbar machen kann.</string>
     <string name="k2go_br_restore_damaged">Wiederherstellung abgebrochen. Ihr System startet beim nächsten Start im Wiederherstellungsmodus.</string>
     <string name="k2go_br_cancel_extract_need_ack">Aktivieren Sie das Kontrollkästchen, um zu bestätigen, dass Sie es verstanden haben.</string>
+    <string name="k2go_br_cancel_backup_title">Sicherung abbrechen?</string>
+    <string name="k2go_br_cancel_backup_body">Diese Sicherung ist nicht abgeschlossen. Beim Abbrechen wird die unvollständige Datei entfernt — Sie können jederzeit eine neue Sicherung starten.</string>
+    <string name="k2go_br_cancel_backup_confirm">Sicherung abbrechen</string>
+    <string name="k2go_br_cancel_backup_keep">Sicherung fortsetzen</string>
     <string name="k2go_br_restore_unreadable">Die ausgewählte Datei konnte nicht gelesen werden, daher wurde nichts geändert.</string>
     <string name="deepop_channel_name">Sichern &amp; wiederherstellen</string>
     <string name="deepop_channel_desc">Hält ein Backup oder eine Wiederherstellung sicher im Hintergrund am Laufen</string>