Fix 16 bugs found by code review across all download modules

Critical fixes:
- Post-processor: remove double attempts increment (onProgress + onArchiveFailure both counted)
- Post-processor: fix slot leak when signal aborted after acquireSlot
- Scheduler: reset global watchdog high-water mark after stall event (prevents permanent misfires)
- Pipeline/DM: fix isPathInsideDir path traversal (add trailing separator check)
- Retry-manager: check per-kind exhaustion before shelve threshold (prevents bypass)
- Retry-manager: add MAX_SHELVE_COUNT=5 cap to prevent infinite shelve cycling

Important fixes:
- Scheduler: clear retryDelays and providerCooldowns on start()
- Scheduler: skip already-aborting slots in stall detection
- Download-manager: fix cleanupAfterExtraction using extractDir instead of outputDir for link removal
- Download-manager: add "extracting" to package normalizeSessionStatuses
- Download-manager: clear activeTasks map on stop()
- Download-manager: remove useless cachedDirectUrls re-insertion after success
- Stream-writer: remove duplicate truncation code in error path
- Stream-writer: skip alignedFlush in finally when bodyError already set (avoids 5min drain wait)
- Stream-writer: re-read elapsed after speed limiter sleep for accurate window reset
- Error-classifier: add HTTP 401 (Forbidden) and 410 (NotFound) classification

Tests updated to match new shelve/kind-exhaustion priority and 401 classification.
All 216 tests pass, build verified.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main/download/download-manager.ts

@@ -88,7 +88,10 @@ function pathKey(p: string): string {
 }
 
 function isPathInsideDir(filePath: string, dirPath: string): boolean {
-  return path.resolve(filePath).toLowerCase().startsWith(path.resolve(dirPath).toLowerCase());
+  const normalizedFile = path.resolve(filePath).toLowerCase();
+  let normalizedDir = path.resolve(dirPath).toLowerCase();
+  if (!normalizedDir.endsWith(path.sep)) normalizedDir += path.sep;
+  return normalizedFile.startsWith(normalizedDir) || normalizedFile === normalizedDir.slice(0, -1);
 }
 
 function providerLabel(p: string | null): string {
@@ -752,6 +755,7 @@ export class DownloadManager extends EventEmitter {
       slot.abortReason = "stop";
       slot.abortController.abort("stop");
     }
+    this.activeTasks.clear();
 
     // Reset non-finished items
     for (const item of Object.values(this.session.items)) {
@@ -1069,16 +1073,6 @@ export class DownloadManager extends EventEmitter {
       this.cachedDirectUrls.delete(slot.itemId);
       this.retryManager.removeItem(slot.itemId);
 
-      // Cache the direct URL in case another item from same package needs it
-      if (result.directUrl) {
-        this.cachedDirectUrls.set(slot.itemId, {
-          url: result.directUrl,
-          provider: result.provider,
-          label: result.providerLabel || "",
-          skipTls: result.skipTlsVerify || false,
-        });
-      }
-
       logger.info(`Download complete: ${item.fileName} (${humanSize(item.downloadedBytes)})`);
 
       // Check if package is done → trigger post-processing
@@ -1331,7 +1325,8 @@ export class DownloadManager extends EventEmitter {
 
   private async cleanupAfterExtraction(pkg: PackageEntry): Promise<void> {
     if (this.settings.removeLinkFilesAfterExtract) {
-      await removeDownloadLinkArtifacts(pkg.extractDir);
+      // Link artifacts (.lnk files) are in the download directory, not extract dir
+      await removeDownloadLinkArtifacts(pkg.outputDir);
     }
     if (this.settings.removeSamplesAfterExtract) {
       await removeSampleArtifacts(pkg.extractDir);
@@ -1594,7 +1589,7 @@ export class DownloadManager extends EventEmitter {
       }
     }
     for (const pkg of Object.values(this.session.packages)) {
-      if (pkg.status === "downloading" || pkg.status === "validating") {
+      if (pkg.status === "downloading" || pkg.status === "validating" || pkg.status === "extracting") {
         pkg.status = "queued";
         pkg.updatedAt = nowMs();
       }

src/main/download/error-classifier.ts

@@ -241,6 +241,11 @@ export function classifyHttpStatus(ctx: HttpClassifyContext): DownloadError {
         httpStatus: status,
       });
 
+    case status === 401:
+      return new DownloadError(DownloadErrorKind.Forbidden, msg, {
+        httpStatus: status,
+      });
+
     case status === 403:
       return new DownloadError(DownloadErrorKind.Forbidden, msg, {
         httpStatus: status,
@@ -251,6 +256,11 @@ export function classifyHttpStatus(ctx: HttpClassifyContext): DownloadError {
         httpStatus: status,
       });
 
+    case status === 410:
+      return new DownloadError(DownloadErrorKind.NotFound, msg, {
+        httpStatus: status,
+      });
+
     case status >= 500:
       return new DownloadError(DownloadErrorKind.ServerError, msg, {
         httpStatus: status,

src/main/download/pipeline.ts

@@ -292,8 +292,10 @@ function filenameFromUrl(url: string): string {
 
 function isPathInsideDir(filePath: string, dirPath: string): boolean {
   const normalizedFile = path.resolve(filePath).toLowerCase();
-  const normalizedDir = path.resolve(dirPath).toLowerCase();
-  return normalizedFile.startsWith(normalizedDir);
+  let normalizedDir = path.resolve(dirPath).toLowerCase();
+  // Ensure trailing separator to prevent "C:\downloads\pack-evil" matching "C:\downloads\pack"
+  if (!normalizedDir.endsWith(path.sep)) normalizedDir += path.sep;
+  return normalizedFile.startsWith(normalizedDir) || normalizedFile === normalizedDir.slice(0, -1);
 }
 
 function providerDisplayName(provider: DebridProvider | null): string {

src/main/download/post-processor.ts

@@ -207,7 +207,10 @@ export class PostProcessor extends EventEmitter {
   private async runPostProcessing(packageId: string, options: PostProcessOptions): Promise<void> {
     // Acquire slot
     await this.acquireSlot(options.signal);
-    if (options.signal.aborted) return;
+    if (options.signal.aborted) {
+      this.releaseSlot();
+      return;
+    }
 
     const state: PackagePostProcessState = this.states.get(packageId) || {
       packageId,
@@ -335,13 +338,11 @@ export class PostProcessor extends EventEmitter {
         // Track individual archive completion
         if (update.archiveDone) {
           const archiveState = state.archives.get(update.archiveName);
-          if (archiveState) {
+          if (archiveState && update.archiveSuccess) {
             archiveState.attempts++;
-            if (update.archiveSuccess) {
-              archiveState.status = "done";
-            }
-            // If not success, onArchiveFailure will handle it
+            archiveState.status = "done";
           }
+          // If not success, onArchiveFailure will handle it (and increment attempts)
         }
       },
       onArchiveFailure: (failure: ExtractArchiveFailure) => {

src/main/download/retry-manager.ts

@@ -199,6 +199,7 @@ export interface RetryDecision {
 
 const SHELVE_THRESHOLD = 15;
 const SHELVE_DELAY_MS = 90_000;
+const MAX_SHELVE_COUNT = 5;
 
 // ---------------------------------------------------------------------------
 // RetryManager
@@ -248,12 +249,8 @@ export class RetryManager {
       ? Math.min(policy.maxRetries, this.userRetryLimit)
       : policy.maxRetries;
 
-    // Check shelving threshold BEFORE individual kind limits
-    if (state.totalFailures >= SHELVE_THRESHOLD) {
-      return this.shelve(state, kind);
-    }
-
-    // Check if this specific kind exhausted its retries
+    // Check if this specific kind exhausted its retries FIRST
+    // (shelving must not bypass per-kind limits)
     if (kindCount > effectiveMax) {
       return {
         shouldRetry: false,
@@ -263,6 +260,19 @@ export class RetryManager {
       };
     }
 
+    // Shelving threshold: too many total failures across all kinds
+    if (state.totalFailures >= SHELVE_THRESHOLD) {
+      if (state.shelveCount >= MAX_SHELVE_COUNT) {
+        return {
+          shouldRetry: false,
+          delayMs: 0,
+          actions: [],
+          reason: `Maximale Shelve-Zyklen erreicht (${MAX_SHELVE_COUNT})`,
+        };
+      }
+      return this.shelve(state, kind);
+    }
+
     // Retry — compute delay and actions
     const delayMs = this.computeDelay(policy, kindCount);
     const actions = this.computeActions(policy);

src/main/download/scheduler.ts

@@ -96,6 +96,8 @@ export class Scheduler extends EventEmitter {
     this.scopedPackageIds = new Set(scopedIds || []);
     this.lastGlobalProgressBytes = 0;
     this.lastGlobalProgressAt = Date.now();
+    this.retryDelays.clear();
+    this.providerCooldowns.clear();
 
     const myGeneration = this.generation;
     const loopIntervalMs = 120;
@@ -430,6 +432,7 @@ export class Scheduler extends EventEmitter {
 
     for (const slot of this.slots.values()) {
       if (slot.blockedOnDiskWrite) continue; // Don't count disk waits
+      if (slot.abortReason !== "none") continue; // Already aborting
       const idleMs = now - slot.lastHeartbeatAt;
       if (idleMs > this.config.stallTimeoutMs) {
         this.emit("stall-detected", { itemId: slot.itemId, idleMs });
@@ -460,7 +463,10 @@ export class Scheduler extends EventEmitter {
         .filter(s => !s.blockedOnDiskWrite)
         .map(s => s.itemId);
       this.emit("global-stall", { itemIds: stalledIds });
-      this.lastGlobalProgressAt = now; // Reset to avoid rapid-fire events
+      // Reset both timestamp and high-water mark so after retry
+      // (where bytesAtHeartbeat resets to 0) the watchdog doesn't misfire
+      this.lastGlobalProgressAt = now;
+      this.lastGlobalProgressBytes = totalBytes;
     }
   }
 

src/main/download/stream-writer.ts

@@ -424,12 +424,14 @@ export async function streamToFile(opts: StreamOptions): Promise<StreamResult> {
           // Speed limiting
           if (speedLimitBps > 0) {
             speedLimitWindowBytes += buffer.length;
-            const elapsed = (nowMs() - speedLimitWindowStart) / 1000;
+            let elapsed = (nowMs() - speedLimitWindowStart) / 1000;
             if (elapsed > 0.1) {
               const currentRate = speedLimitWindowBytes / elapsed;
               if (currentRate > speedLimitBps) {
                 const sleepMs = Math.floor(((speedLimitWindowBytes / speedLimitBps) - elapsed) * 1000);
                 if (sleepMs > 10) await sleep(Math.min(sleepMs, 1000));
+                // Re-read elapsed after sleep so window reset check is accurate
+                elapsed = (nowMs() - speedLimitWindowStart) / 1000;
               }
               if (elapsed >= 1) {
                 speedLimitWindowStart = nowMs();
@@ -508,8 +510,10 @@ export async function streamToFile(opts: StreamOptions): Promise<StreamResult> {
       bodyError = error;
       log("WARN", "Download body error", { attempt, error: errorMessage(error) });
     } finally {
-      // Flush remaining buffered data
-      try { await alignedFlush(true); } catch (e) { if (!bodyError) bodyError = e; }
+      // Flush remaining buffered data (skip if error already — avoid 5min drain wait)
+      if (!bodyError) {
+        try { await alignedFlush(true); } catch (e) { bodyError = e; }
+      }
 
       // Close stream
       try {
@@ -538,13 +542,8 @@ export async function streamToFile(opts: StreamOptions): Promise<StreamResult> {
         } catch { /* best-effort */ }
       }
 
-      // Truncate pre-allocated file to actual written bytes on error
-      if (bodyError && preAllocated && totalBytes && written < totalBytes) {
-        try { await fs.promises.truncate(effectiveTargetPath, written); } catch {}
-      }
-
       if (bodyError) {
-        // On error: truncate pre-allocated sparse file
+        // On error: truncate pre-allocated sparse file to actual written bytes
         if (preAllocated && totalBytes && written < totalBytes) {
           try { await fs.promises.truncate(effectiveTargetPath, written); } catch {}
         }