Release v1.7.225

Ursache: Session-Writes (writeFile + atomic rename) liefen ohne fsync. Waehrend eines
Downloads feuert persistSoon alle 700ms-3s, die Session-Datei bleibt damit dauerhaft
dirty im OS-Cache. Bei hartem Stromausfall auf NTFS ist die rename-Metadatentransaktion
journaled (durable), aber die Datenbloecke der temp-Datei sind nicht geflusht -> primary
zeigt nach Reboot auf Null/Garbage. Die .bak-Kopie stammt per copyFileSync aus einer
ebenfalls ungeflushten primary -> ebenfalls korrupt. loadSession faellt durch
primary -> bak -> temp auf emptySession() durch, und der naechste persistSoon speichert
diese leere Session ueber die Platte -> dauerhaft leer. Tritt nur bei UNSAUBEREM Neustart
auf (sauberes Beenden flusht ohnehin).

Fix in drei Schichten:
- Durable atomic write: temp wird vor dem rename gefsynct. Reihenfolge zwingend
  write -> fsync -> close -> rename (NTFS kann eine Datei mit offenem Handle nicht renamen).
  Sync-Pfad via openSync/writeSync/fsyncSync/closeSync, Async-Pfad via FileHandle.sync()
  (laeuft auf dem libuv-Threadpool, blockiert den Hot-Path nicht). Kein Throttle: ein
  throttle-skip wuerde eine ungeflushte temp ueber die durable primary renamen und das
  Korruptionsfenster wieder oeffnen.
- Read-Retry: readSessionFile wiederholt bei transienten Sperren (EBUSY/EPERM/EAGAIN, z.B.
  Virenscanner/Disk-not-ready beim Boot) 5x mit Backoff. EACCES und JSON-Parse-Fehler
  werden nicht wiederholt.
- Empty-Clobber-Guard: loadSessionWithStatus meldet, ob alle Tiers unlesbar waren (Status
  empty-unreadable). In dem Fall blockiert der DownloadManager das Speichern einer leeren
  Session ueber vorhandene Daten, bis wieder echte Daten vorliegen; die erste nicht-leere
  Speicherung hebt den Schutz auf.

Tests: tests/session-restart-loss.test.ts um Status-Klassifizierung, fsync-Nachweis,
async-Roundtrip (close-before-rename), EBUSY-Retry und Guard-Clear-Pfad erweitert.
Suite 929 gruen, tsc unveraendert bei 6 Baseline-Fehlern.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.7.224",
+  "version": "1.7.225",
   "description": "Desktop downloader",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",

src/main/app-controller.ts

@@ -39,7 +39,7 @@ import { getItemLogPath, initItemLogs, shutdownItemLogs } from "./item-log";
 import { getPackageLogPath, initPackageLogs, shutdownPackageLogs } from "./package-log";
 import { initSessionLog, getSessionLogPath, shutdownSessionLog } from "./session-log";
 import { MegaWebFallback } from "./mega-web-fallback";
-import { addHistoryEntry, addHistoryEntryForRetention, cancelPendingAsyncSaves, clearHistory, createStoragePaths, loadHistory, loadHistoryForRetention, loadSession, loadSettings, normalizeHistoryEntry, normalizeLoadedSession, normalizeLoadedSessionTransientFields, normalizeSettings, removeHistoryEntry, resetHistoryForRetention, saveHistory, saveSession, saveSettings } from "./storage";
+import { addHistoryEntry, addHistoryEntryForRetention, cancelPendingAsyncSaves, clearHistory, createStoragePaths, loadHistory, loadHistoryForRetention, loadSessionWithStatus, loadSettings, normalizeHistoryEntry, normalizeLoadedSession, normalizeLoadedSessionTransientFields, normalizeSettings, removeHistoryEntry, resetHistoryForRetention, saveHistory, saveSession, saveSettings } from "./storage";
 import { abortActiveUpdateDownload, checkGitHubUpdate, installLatestUpdate } from "./update";
 import { runInstallWithResume } from "./update-install-flow";
 import { rotateDebugToken, startDebugServer, stopDebugServer, restartDebugServer, getDebugServerRuntimeStatus, getActiveDebugToken, getDebugAllowlist, writeDebugServerConfig, clearDebugToken } from "./debug-server";
@@ -112,7 +112,8 @@ export class AppController {
     initTraceLog(this.storagePaths.baseDir);
     this.settings = loadSettings(this.storagePaths);
     resetHistoryForRetention(this.storagePaths, this.settings.historyRetentionMode);
-    const session = loadSession(this.storagePaths);
+    const loadResult = loadSessionWithStatus(this.storagePaths);
+    const session = loadResult.session;
     this.megaWebFallback = new MegaWebFallback(() => ({
       login: this.settings.megaLogin,
       password: this.settings.megaPassword
@@ -126,6 +127,7 @@ export class AppController {
       realDebridWebUnrestrict: (link: string, signal?: AbortSignal) => this.realDebridWebFallback.unrestrict(link, signal),
       bestDebridWebUnrestrict: (link: string, signal?: AbortSignal) => this.bestDebridWebFallback.unrestrict(link, signal),
       invalidateMegaSession: () => this.megaWebFallback.invalidateSession(),
+      protectEmptyClobber: loadResult.status === "empty-unreadable",
       onHistoryEntry: (entry: HistoryEntry) => {
         addHistoryEntryForRetention(this.storagePaths, this.settings.historyRetentionMode, entry, this.historyLimits());
       }

src/main/download-manager.ts

@@ -363,6 +363,7 @@ type DownloadManagerOptions = {
   bestDebridWebUnrestrict?: BestDebridWebUnrestrictor;
   invalidateMegaSession?: () => void;
   onHistoryEntry?: HistoryEntryCallback;
+  protectEmptyClobber?: boolean;
 };
 
 function generateHistoryId(): string {
@@ -1688,6 +1689,10 @@ export class DownloadManager extends EventEmitter {
 
   public blockAllPersistence = false;
 
+  private protectAgainstEmptyClobber = false;
+
+  private emptyClobberProtectionLogged = false;
+
   private debridService: DebridService;
 
   private invalidateMegaSessionFn?: () => void;
@@ -1831,6 +1836,10 @@ export class DownloadManager extends EventEmitter {
     this.session = session;
     this.itemCount = Object.keys(this.session.items).length;
     this.storagePaths = storagePaths;
+    this.protectAgainstEmptyClobber = Boolean(options.protectEmptyClobber);
+    if (this.protectAgainstEmptyClobber) {
+      logger.warn("Session-Schutz aktiv: Start mit unlesbarer Session — leere Speicherungen blockiert, bis echte Daten vorliegen");
+    }
     this.debridService = new DebridService(settings, {
       megaWebUnrestrict: options.megaWebUnrestrict,
       allDebridWebUnrestrict: options.allDebridWebUnrestrict,
@@ -5821,7 +5830,9 @@ export class DownloadManager extends EventEmitter {
       const itemCount = Object.keys(this.session.items).length;
       logger.info(`Shutdown-Save: ${pkgCount} Pakete, ${itemCount} Items`);
       this.foldRuntimeIntoSettings(nowMs());
+      if (!this.guardBlocksSessionSave()) {
         saveSession(this.storagePaths, this.session);
+      }
       saveSettings(this.storagePaths, this.settings);
     } else {
       logger.info(`Shutdown-Save übersprungen: skipShutdownPersist=${this.skipShutdownPersist}, blockAllPersistence=${this.blockAllPersistence}`);
@@ -6124,10 +6135,29 @@ export class DownloadManager extends EventEmitter {
     }, delay);
   }
 
+  private guardBlocksSessionSave(): boolean {
+    if (!this.protectAgainstEmptyClobber) {
+      return false;
+    }
+    const isEmpty = Object.keys(this.session.packages).length === 0 && Object.keys(this.session.items).length === 0;
+    if (isEmpty) {
+      if (!this.emptyClobberProtectionLogged) {
+        logger.warn("Leere Session-Speicherung uebersprungen (Schutz nach unlesbarem Start) — vorhandene Datei bleibt unangetastet");
+        this.emptyClobberProtectionLogged = true;
+      }
+      return true;
+    }
+    this.protectAgainstEmptyClobber = false;
+    logger.info("Session-Schutz aufgehoben: nicht-leere Session wird wieder normal gespeichert");
+    return false;
+  }
+
   private persistNow(): void {
     const now = nowMs();
     this.lastPersistAt = now;
+    if (!this.guardBlocksSessionSave()) {
       void saveSessionAsync(this.storagePaths, this.session).catch((err) => logger.warn(`saveSessionAsync Fehler: ${compactErrorText(err)}`));
+    }
     if (now - this.lastSettingsPersistAt >= 30000) {
       this.foldRuntimeIntoSettings(now);
       this.lastSettingsPersistAt = now;
@@ -6141,7 +6171,9 @@ export class DownloadManager extends EventEmitter {
     const itemCount = Object.keys(this.session.items).length;
     logger.info(`Pre-Update Sync-Save: ${pkgCount} Pakete, ${itemCount} Items`);
     this.foldRuntimeIntoSettings(nowMs());
+    if (!this.guardBlocksSessionSave()) {
       saveSession(this.storagePaths, this.session);
+    }
     saveSettings(this.storagePaths, this.settings);
   }
 

src/main/storage.ts

@@ -890,21 +890,50 @@ export function normalizeLoadedSessionTransientFields(session: SessionState): Se
   return session;
 }
 
+const TRANSIENT_READ_CODES = new Set(["EBUSY", "EPERM", "EAGAIN"]);
+
+function sleepSyncMs(ms: number): void {
+  if (ms <= 0) {
+    return;
+  }
+  Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0, ms);
+}
+
 function readSessionFile(filePath: string): SessionState | null {
+  let raw: string | null = null;
+  const maxAttempts = 5;
+  for (let attempt = 1; attempt <= maxAttempts; attempt += 1) {
     try {
-    const parsed = JSON.parse(fs.readFileSync(filePath, "utf8")) as unknown;
+      raw = fs.readFileSync(filePath, "utf8");
+      break;
+    } catch (error) {
+      const code = (error as NodeJS.ErrnoException)?.code || "";
+      if (TRANSIENT_READ_CODES.has(code) && attempt < maxAttempts) {
+        const backoffMs = 100 * 2 ** (attempt - 1);
+        logger.warn(`Session-Datei vorübergehend gesperrt (${code}), Versuch ${attempt}/${maxAttempts}, warte ${backoffMs}ms: ${filePath}`);
+        sleepSyncMs(backoffMs);
+        continue;
+      }
+      if (code === "EACCES" || code === "EPERM") {
+        logger.error(`Session-Datei nicht zugreifbar (${code}): ${filePath} - pruefe Datei-/Ordner-Berechtigungen fuer Benutzer ${process.env.USERNAME || process.env.USER || "?"}`);
+      } else {
+        logger.error(`Session-Datei nicht lesbar (${code || "?"}): ${filePath}: ${String(error)}`);
+      }
+      return null;
+    }
+  }
+  if (raw === null) {
+    return null;
+  }
+  try {
+    const parsed = JSON.parse(raw) as unknown;
     const session = normalizeLoadedSessionTransientFields(normalizeLoadedSession(parsed));
     const pkgCount = Object.keys(session.packages).length;
     const itemCount = Object.keys(session.items).length;
     logger.info(`Session geladen: ${filePath} (${pkgCount} Pakete, ${itemCount} Items)`);
     return session;
   } catch (error) {
-    const code = (error as NodeJS.ErrnoException)?.code || "";
+    logger.error(`Session-Datei beschädigt (JSON ungültig): ${filePath}: ${String(error)}`);
-    if (code === "EACCES" || code === "EPERM") {
-      logger.error(`Session-Datei nicht zugreifbar (${code}): ${filePath} - pruefe Datei-/Ordner-Berechtigungen fuer Benutzer ${process.env.USERNAME || process.env.USER || "?"}`);
-    } else {
-      logger.error(`Session-Datei nicht lesbar: ${filePath}: ${String(error)}`);
-    }
     return null;
   }
 }
@@ -1004,17 +1033,31 @@ export function emptySession(): SessionState {
   };
 }
 
-export function loadSession(paths: StoragePaths): SessionState {
+export type SessionLoadStatus =
+  | "ok"
+  | "recovered-backup"
+  | "recovered-temp"
+  | "empty-fresh"
+  | "empty-unreadable";
+
+export interface SessionLoadResult {
+  session: SessionState;
+  status: SessionLoadStatus;
+}
+
+export function loadSessionWithStatus(paths: StoragePaths): SessionLoadResult {
   ensureBaseDir(paths.baseDir);
   const backupFile = sessionBackupPath(paths.sessionFile);
+  const syncTempFile = sessionTempPath(paths.sessionFile, "sync");
+  const asyncTempFile = sessionTempPath(paths.sessionFile, "async");
   const primaryExists = fs.existsSync(paths.sessionFile);
+  const backupExists = fs.existsSync(backupFile);
+  const anyTempExists = fs.existsSync(syncTempFile) || fs.existsSync(asyncTempFile);
+
   if (!primaryExists) {
-    const hasRecoverable = fs.existsSync(backupFile)
+    if (!backupExists && !anyTempExists) {
-      || fs.existsSync(sessionTempPath(paths.sessionFile, "sync"))
-      || fs.existsSync(sessionTempPath(paths.sessionFile, "async"));
-    if (!hasRecoverable) {
       logger.info("Keine Session-Datei vorhanden, starte mit leerer Session");
-      return emptySession();
+      return { session: emptySession(), status: "empty-fresh" };
     }
     logger.warn("Session-Primaerdatei fehlt, aber Backup/Temp vorhanden — Wiederherstellung wird versucht");
   }
@@ -1023,7 +1066,7 @@ export function loadSession(paths: StoragePaths): SessionState {
 
   if (primary) {
     const primaryPkgCount = Object.keys(primary.packages).length;
-    if (primaryPkgCount === 0 && fs.existsSync(backupFile)) {
+    if (primaryPkgCount === 0 && backupExists) {
       const backup = readSessionFile(backupFile);
       if (backup) {
         const backupPkgCount = Object.keys(backup.packages).length;
@@ -1031,29 +1074,27 @@ export function loadSession(paths: StoragePaths): SessionState {
           logger.warn(`Session-Datei ist leer (0 Pakete), aber Backup hat ${backupPkgCount} Pakete — verwende Backup`);
           try {
             const payload = JSON.stringify({ ...backup, updatedAt: Date.now() }, safeJsonReplacer);
-            const tempPath = sessionTempPath(paths.sessionFile, "sync");
+            fs.writeFileSync(syncTempFile, payload, "utf8");
-            fs.writeFileSync(tempPath, payload, "utf8");
+            syncRenameWithExdevFallback(syncTempFile, paths.sessionFile);
-            syncRenameWithExdevFallback(tempPath, paths.sessionFile);
           } catch {
           }
-          return backup;
+          return { session: backup, status: "recovered-backup" };
         }
       }
     }
-    return primary;
+    return { session: primary, status: "ok" };
   }
 
-  const backup = fs.existsSync(backupFile) ? readSessionFile(backupFile) : null;
+  const backup = backupExists ? readSessionFile(backupFile) : null;
   if (backup) {
     logger.warn("Session defekt, Backup-Datei wird verwendet");
     try {
       const payload = JSON.stringify({ ...backup, updatedAt: Date.now() }, safeJsonReplacer);
-      const tempPath = sessionTempPath(paths.sessionFile, "sync");
+      fs.writeFileSync(syncTempFile, payload, "utf8");
-      fs.writeFileSync(tempPath, payload, "utf8");
+      syncRenameWithExdevFallback(syncTempFile, paths.sessionFile);
-      syncRenameWithExdevFallback(tempPath, paths.sessionFile);
     } catch {
     }
-    return backup;
+    return { session: backup, status: "recovered-backup" };
   }
 
   for (const kind of ["sync", "async"] as const) {
@@ -1067,13 +1108,21 @@ export function loadSession(paths: StoragePaths): SessionState {
           fs.writeFileSync(paths.sessionFile, payload, "utf8");
         } catch {
         }
-        return tmpSession;
+        return { session: tmpSession, status: "recovered-temp" };
       }
     }
   }
 
-  logger.error("Session konnte nicht geladen werden (Primary, Backup und Temp-Dateien fehlgeschlagen)");
+  if (primaryExists || backupExists || anyTempExists) {
-  return emptySession();
+    logger.error("Session konnte nicht geladen werden (Primary, Backup und Temp-Dateien fehlgeschlagen) — Schutz gegen leeres Ueberschreiben aktiv");
+    return { session: emptySession(), status: "empty-unreadable" };
+  }
+
+  return { session: emptySession(), status: "empty-fresh" };
+}
+
+export function loadSession(paths: StoragePaths): SessionState {
+  return loadSessionWithStatus(paths).session;
 }
 
 export function saveSession(paths: StoragePaths, session: SessionState): void {
@@ -1088,7 +1137,13 @@ export function saveSession(paths: StoragePaths, session: SessionState): void {
   const payload = JSON.stringify({ ...session, updatedAt: Date.now() }, safeJsonReplacer);
   const tempPath = sessionTempPath(paths.sessionFile, "sync");
   try {
-    fs.writeFileSync(tempPath, payload, "utf8");
+    const fd = fs.openSync(tempPath, "w");
+    try {
+      fs.writeSync(fd, payload);
+      fs.fsyncSync(fd);
+    } finally {
+      fs.closeSync(fd);
+    }
     syncRenameWithExdevFallback(tempPath, paths.sessionFile);
   } catch (error) {
     try { fs.rmSync(tempPath, { force: true }); } catch {  }
@@ -1104,7 +1159,13 @@ async function writeSessionPayload(paths: StoragePaths, payload: string, generat
   await fs.promises.mkdir(paths.baseDir, { recursive: true });
   await fsp.copyFile(paths.sessionFile, sessionBackupPath(paths.sessionFile)).catch(() => {});
   const tempPath = sessionTempPath(paths.sessionFile, "async");
-  await fsp.writeFile(tempPath, payload, "utf8");
+  const handle = await fsp.open(tempPath, "w");
+  try {
+    await handle.writeFile(payload, "utf8");
+    await handle.sync();
+  } finally {
+    await handle.close();
+  }
   if (generation < syncSaveGeneration) {
     await fsp.rm(tempPath, { force: true }).catch(() => {});
     return;