Fix extraction failure on long paths (>260 chars) with \?\ prefix

Add longPathForWindows() helper that prefixes extract target directories
with \?\ on Windows, bypassing the 260-char MAX_PATH limit. Applied to
both WinRAR/UnRAR and 7z arguments. Fixes "Die Syntax für den
Dateinamen, Verzeichnisnamen" errors when archive internal directories
create deeply nested output paths.

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.5.15",
+  "version": "1.5.16",
   "description": "Real-Debrid Downloader Desktop (Electron + React + TypeScript)",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",

src/main/extractor.ts

@@ -8,6 +8,21 @@ import { logger } from "./logger";
 import { removeDownloadLinkArtifacts, removeSampleArtifacts } from "./cleanup";
 
 const DEFAULT_ARCHIVE_PASSWORDS = ["", "serienfans.org", "serienjunkies.org"];
+
+/**
+ * On Windows, prefix an absolute path with \\?\ to bypass the 260-char MAX_PATH limit.
+ * WinRAR 5.x+ and 7-Zip support this prefix for long output paths.
+ */
+function longPathForWindows(p: string): string {
+  if (process.platform !== "win32") return p;
+  const resolved = path.resolve(p);
+  if (resolved.startsWith("\\\\?\\")) return resolved;
+  if (resolved.startsWith("\\\\")) {
+    // UNC path \\server\share -> \\?\UNC\server\share
+    return "\\\\?\\UNC\\" + resolved.slice(2);
+  }
+  return "\\\\?\\" + resolved;
+}
 const NO_EXTRACTOR_MESSAGE = "WinRAR/UnRAR nicht gefunden. Bitte WinRAR installieren.";
 
 let resolvedExtractorCommand: string | null = null;
@@ -606,13 +621,14 @@ export function buildExternalExtractArgs(
     const perfArgs = usePerformanceFlags && shouldUseExtractorPerformanceFlags()
       ? ["-idc", extractorThreadSwitch()]
       : [];
-    return ["x", overwrite, pass, "-y", ...perfArgs, archivePath, `${targetDir}${path.sep}`];
+    const longTarget = longPathForWindows(targetDir);
+    return ["x", overwrite, pass, "-y", ...perfArgs, archivePath, `${longTarget}${path.sep}`];
   }
 
   const overwrite = mode === "overwrite" ? "-aoa" : mode === "rename" ? "-aou" : "-aos";
   // NOTE: Same password-in-args limitation as above applies to 7z as well.
   const pass = password ? `-p${password}` : "-p";
-  return ["x", "-y", overwrite, pass, archivePath, `-o${targetDir}`];
+  return ["x", "-y", overwrite, pass, archivePath, `-o${longPathForWindows(targetDir)}`];
 }
 
 async function resolveExtractorCommandInternal(): Promise<string> {

tests/extractor.test.ts

@@ -20,14 +20,15 @@ describe("extractor", () => {
     expect(overwriteArgs).toContain("-idc");
     expect(overwriteArgs.some((value) => /^-mt\d+$/i.test(value))).toBe(true);
     expect(overwriteArgs[overwriteArgs.length - 2]).toBe("archive.rar");
-    expect(overwriteArgs[overwriteArgs.length - 1]).toBe("C:\\target\\");
+    const winrarTarget = process.platform === "win32" ? "\\\\?\\C:\\target\\" : "C:\\target\\";
+    expect(overwriteArgs[overwriteArgs.length - 1]).toBe(winrarTarget);
 
     const askArgs = buildExternalExtractArgs("WinRAR.exe", "archive.rar", "C:\\target", "ask", "serienfans.org");
     expect(askArgs.slice(0, 4)).toEqual(["x", "-o-", "-pserienfans.org", "-y"]);
     expect(askArgs).toContain("-idc");
     expect(askArgs.some((value) => /^-mt\d+$/i.test(value))).toBe(true);
     expect(askArgs[askArgs.length - 2]).toBe("archive.rar");
-    expect(askArgs[askArgs.length - 1]).toBe("C:\\target\\");
+    expect(askArgs[askArgs.length - 1]).toBe(winrarTarget);
 
     const compatibilityArgs = buildExternalExtractArgs("WinRAR.exe", "archive.rar", "C:\\target", "overwrite", "", false);
     expect(compatibilityArgs).not.toContain("-idc");
@@ -455,7 +456,8 @@ describe("extractor", () => {
     expect(args7z).toContain("-aoa");
     expect(args7z).toContain("-p");
     expect(args7z).toContain("archive.7z");
-    expect(args7z).toContain("-oC:\\target");
+    const sevenZTarget = process.platform === "win32" ? "-o\\\\?\\C:\\target" : "-oC:\\target";
+    expect(args7z).toContain(sevenZTarget);
   });
 
   it("builds 7z args with skip conflict mode", () => {