Fix bulk download edge cases and improve robustness

- FolderPickerWriter: throw AbortError on cancel instead of returning null
- FolderPickerWriter: add try/catch with abort() to release file locks on failure
- ZipNeutralinoWriter: move writeBinaryFile after response.body validation
- bulkDownloadSettings: migrate legacy key and validate stored values
- download-utils: catch ffmpeg cancellation via signal.aborted
- downloads.js: use consistent Neutralino detection with bridge module
- download-utils: use strict equality for flac extension check

js/bulk-download-writer.ts

@@ -98,11 +98,11 @@ export class ZipNeutralinoWriter implements IBulkDownloadWriter {
         }
 
         const { downloadZip } = await loadClientZip();
-        await bridge.filesystem.writeBinaryFile(savePath, new ArrayBuffer(0));
-
         const response = downloadZip(files);
         if (!response.body) throw new Error('ZIP response body is null');
 
+        await bridge.filesystem.writeBinaryFile(savePath, new ArrayBuffer(0));
+
         const reader = response.body.getReader();
         let receivedLength = 0;
 
@@ -138,10 +138,17 @@ export class FolderPickerWriter implements IBulkDownloadWriter {
     static async create(): Promise<FolderPickerWriter> {
         // showDirectoryPicker is part of the File System Access API (not yet in all TS DOM libs)
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        const dirHandle: FileSystemDirectoryHandle = await (window as any).showDirectoryPicker({
-            mode: 'readwrite',
-        });
-        return new FolderPickerWriter(dirHandle);
+        try {
+            const dirHandle: FileSystemDirectoryHandle = await (window as any).showDirectoryPicker({
+                mode: 'readwrite',
+            });
+            return new FolderPickerWriter(dirHandle);
+        } catch (error) {
+            if (error instanceof DOMException && error.name === 'AbortError') {
+                throw error;
+            }
+            throw new DOMException('User cancelled directory picker', 'AbortError');
+        }
     }
 
     async write(files: AsyncIterable<WriterEntry>): Promise<void> {
@@ -158,23 +165,25 @@ export class FolderPickerWriter implements IBulkDownloadWriter {
             const fileHandle = await currentDir.getFileHandle(filename, { create: true });
             const writable = await fileHandle.createWritable();
 
-            const { input } = file;
-            if (input instanceof Blob) {
-                await writable.write(input);
-            } else if (typeof input === 'string') {
-                await writable.write(new Blob([input], { type: 'text/plain' }));
-            } else {
-                // ArrayBuffer or Uint8Array – wrap in a Blob to guarantee strict typing.
-                // Use byteOffset/byteLength so only the view's range is included, not the
-                // whole backing ArrayBuffer (which may be larger due to pooling).
-                const buf =
-                    input instanceof Uint8Array
-                        ? input.buffer.slice(input.byteOffset, input.byteOffset + input.byteLength)
-                        : input;
-                await writable.write(new Blob([buf as ArrayBuffer]));
-            }
+            try {
+                const { input } = file;
+                if (input instanceof Blob) {
+                    await writable.write(input);
+                } else if (typeof input === 'string') {
+                    await writable.write(new Blob([input], { type: 'text/plain' }));
+                } else {
+                    const buf =
+                        input instanceof Uint8Array
+                            ? input.buffer.slice(input.byteOffset, input.byteOffset + input.byteLength)
+                            : input;
+                    await writable.write(new Blob([buf as ArrayBuffer]));
+                }
 
-            await writable.close();
+                await writable.close();
+            } catch (error) {
+                await writable.abort();
+                throw error;
+            }
         }
     }
 }

js/download-utils.ts

@@ -64,7 +64,7 @@ export async function applyAudioPostProcessing(
 
             if (await containerFmt?.needsTranscode(blob)) {
                 blob = await transcodeWithContainerFormat(blob, containerFmt, onProgress, signal);
-            } else if (extension == 'flac') {
+            } else if (extension === 'flac') {
                 blob = await rebuildFlacWithoutMetadata(blob);
             } else {
                 blob = await ffmpegNewContainer(
@@ -76,7 +76,7 @@ export async function applyAudioPostProcessing(
                 );
             }
         } catch (error) {
-            if ((error as Error)?.name === 'AbortError') {
+            if ((error as Error)?.name === 'AbortError' || signal?.aborted) {
                 throw error;
             }
 

js/downloads.js

@@ -669,7 +669,9 @@ async function bulkDownloadToZip(
  * or null when individual sequential downloads should be used.
  */
 async function createBulkWriter(folderName) {
-    const isNeutralino = window.NL_MODE === true;
+    const isNeutralino =
+        typeof window !== 'undefined' &&
+        (window.NL_MODE || window.location.search.includes('mode=neutralino') || window.parent !== window);
     const method = bulkDownloadSettings.getMethod();
     const forceZipBlob = bulkDownloadSettings.shouldForceZipBlob();
     const hasFileSystemAccess = 'showSaveFilePicker' in window && 'createWritable' in FileSystemFileHandle.prototype;
@@ -679,8 +681,14 @@ async function createBulkWriter(folderName) {
         return new ZipNeutralinoWriter(folderName);
     }
     if (method === 'folder' && hasFolderPicker) {
-        // FolderPickerWriter.create() throws AbortError if the user cancels
-        return await FolderPickerWriter.create();
+        try {
+            return await FolderPickerWriter.create();
+        } catch (error) {
+            if (error instanceof DOMException && error.name === 'AbortError') {
+                throw error;
+            }
+            return null;
+        }
     }
     if (method === 'individual') {
         return null;

js/storage.js

@@ -637,11 +637,23 @@ export const trackDateSettings = {
 export const bulkDownloadSettings = {
     METHOD_KEY: 'bulk-download-method',
     FORCE_ZIP_BLOB_KEY: 'bulk-download-force-zip-blob',
+    LEGACY_INDIVIDUAL_KEY: 'force-individual-downloads',
+    VALID_METHODS: ['zip', 'folder', 'individual'],
 
     /** Returns the selected bulk download method: 'zip' | 'folder' | 'individual' */
     getMethod() {
         try {
-            return localStorage.getItem(this.METHOD_KEY) || 'zip';
+            const stored = localStorage.getItem(this.METHOD_KEY);
+            if (stored && this.VALID_METHODS.includes(stored)) {
+                return stored;
+            }
+            const legacy = localStorage.getItem(this.LEGACY_INDIVIDUAL_KEY);
+            if (legacy === 'true') {
+                localStorage.setItem(this.METHOD_KEY, 'individual');
+                localStorage.removeItem(this.LEGACY_INDIVIDUAL_KEY);
+                return 'individual';
+            }
+            return 'zip';
         } catch {
             return 'zip';
         }