fix: prevent youtube metadata extraction timeout

This fixes an issue where node child processes spawned by yt-dlp would keep standard output pipes open, preventing the EOF event from firing and causing the application to hang until a 30s timeout occurred.

CHANGELOG.md

@@ -20,6 +20,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Applied rate-limiting and text length bounds to the custom `firelink://` scheme to mitigate DoS and injection attempts.
 
 ### Fixes
+- Fixed a metadata extraction timeout when downloading from YouTube by preventing child processes from holding process pipes open.
+- Resolved an issue to correctly assign filenames for auto-captured downloads.
 - Restored the UUID fallback for token generation to prevent silent failures if secure random byte generation fails.
 - Hardened local API security by immediately rejecting requests if the expected pairing token is completely empty.
 - Implemented a thread-safe cleanup mechanism for temporary directories to resolve a concurrency race condition during engine cancellation.

Sources/Firelink/MediaExtractionEngine.swift

@@ -452,25 +452,19 @@ private final class YTDLPMetadataProcess: @unchecked Sendable {
             process.standardError = errorPipe
             process.standardInput = nil
 
-            let readGroup = DispatchGroup()
-
-            readGroup.enter()
             outputPipe.fileHandleForReading.readabilityHandler = { handle in
                 let data = handle.availableData
                 if data.isEmpty {
                     handle.readabilityHandler = nil
-                    readGroup.leave()
                 } else {
                     outputBuffer.append(data)
                 }
             }
 
-            readGroup.enter()
             errorPipe.fileHandleForReading.readabilityHandler = { handle in
                 let data = handle.availableData
                 if data.isEmpty {
                     handle.readabilityHandler = nil
-                    readGroup.leave()
                 } else {
                     errorBuffer.append(data)
                 }
@@ -481,7 +475,10 @@ private final class YTDLPMetadataProcess: @unchecked Sendable {
             }
 
             process.terminationHandler = { finishedProcess in
-                readGroup.notify(queue: .global()) {
+                // Allow a brief moment for final pipe data to flush
+                DispatchQueue.global().asyncAfter(deadline: .now() + 0.25) {
+                    outputPipe.fileHandleForReading.readabilityHandler = nil
+                    errorPipe.fileHandleForReading.readabilityHandler = nil
                     if finishedProcess.terminationStatus == 0 {
                         continuation.resume(returning: outputBuffer.data)
                     } else {