harden qobuz and downloader reliability edge cases

internal/download/downloader.go

@@ -81,7 +81,13 @@ func (d *Downloader) FileDeezerEncrypted(ctx context.Context, sourceURL, outputP
 	if err != nil {
 		return err
 	}
-	defer func() { _ = out.Close() }()
+	success := false
+	defer func() {
+		_ = out.Close()
+		if !success {
+			_ = os.Remove(outputPath)
+		}
+	}()
 
 	var bar *mpb.Bar
 	if d.ProgressEnabled() && resp.ContentLength > 0 {
@@ -111,6 +117,7 @@ func (d *Downloader) FileDeezerEncrypted(ctx context.Context, sourceURL, outputP
 	buf := make([]byte, deezerBFChunkSize)
 	dec := make([]byte, deezerBFChunkSize)
 	chunkIndex := 0
+	totalRead := int64(0)
 	for {
 		n, readErr := io.ReadFull(resp.Body, buf)
 		if readErr == io.EOF {
@@ -128,6 +135,7 @@ func (d *Downloader) FileDeezerEncrypted(ctx context.Context, sourceURL, outputP
 		if _, err = out.Write(chunk); err != nil {
 			return err
 		}
+		totalRead += int64(n)
 		if bar != nil {
 			bar.IncrBy(n)
 		}
@@ -136,6 +144,10 @@ func (d *Downloader) FileDeezerEncrypted(ctx context.Context, sourceURL, outputP
 			break
 		}
 	}
+	if resp.ContentLength > 0 && totalRead != resp.ContentLength {
+		return io.ErrUnexpectedEOF
+	}
+	success = true
 	return nil
 }
 
@@ -170,7 +182,13 @@ func (d *Downloader) file(ctx context.Context, sourceURL, outputPath string, all
 	if err != nil {
 		return err
 	}
-	defer func() { _ = out.Close() }()
+	success := false
+	defer func() {
+		_ = out.Close()
+		if !success {
+			_ = os.Remove(outputPath)
+		}
+	}()
 
 	if d.ProgressEnabled() && allowProgress && resp.ContentLength > 0 {
 		d.barStarted.Store(1)
@@ -191,12 +209,14 @@ func (d *Downloader) file(ctx context.Context, sourceURL, outputPath string, all
 			mpb.BarRemoveOnComplete(),
 		)
 		buf := make([]byte, 256*1024)
+		totalWritten := int64(0)
 		for {
 			n, readErr := reader.Read(buf)
 			if n > 0 {
 				if _, writeErr := out.Write(buf[:n]); writeErr != nil {
 					return writeErr
 				}
+				totalWritten += int64(n)
 				bar.IncrBy(n)
 			}
 			if readErr != nil {
@@ -206,12 +226,23 @@ func (d *Downloader) file(ctx context.Context, sourceURL, outputPath string, all
 				return readErr
 			}
 		}
+		if resp.ContentLength > 0 && totalWritten != resp.ContentLength {
+			return io.ErrUnexpectedEOF
+		}
 	} else {
-		if _, err = io.Copy(out, reader); err != nil {
+		written, copyErr := io.Copy(out, reader)
+		if copyErr != nil {
+			return copyErr
+		}
+		if resp.ContentLength > 0 && written != resp.ContentLength {
+			return io.ErrUnexpectedEOF
+		}
+		if err = out.Sync(); err != nil {
 			return err
 		}
 	}
 
+	success = true
 	return nil
 }
 
@@ -268,6 +299,7 @@ func (d *Downloader) streamManifestWithFFmpeg(ctx context.Context, sourceURL, ou
 	cmd := exec.CommandContext(ctx, "ffmpeg", args...)
 	output, err := cmd.CombinedOutput()
 	if err != nil {
+		_ = os.Remove(outputPath)
 		return fmt.Errorf("ffmpeg stream copy failed: %w: %s", err, string(output))
 	}
 	return nil