Fix file handle cleanup in download/sinf replication flows

pkg/appstore/appstore_download.go

@@ -264,6 +264,7 @@ func (t *appstore) applyPatches(item downloadItemResult, acc Account, src, dst s
 	if err != nil {
 		return fmt.Errorf("failed to open file: %w", err)
 	}
+	defer dstFile.Close()
 
 	dstZip := zip.NewWriter(dstFile)
 	defer dstZip.Close()

pkg/appstore/appstore_replicate_sinf.go

@@ -29,15 +29,19 @@
 	if err != nil {
 		return errors.New("failed to open zip reader")
 	}
+	defer zipReader.Close()
 
 	tmpPath := fmt.Sprintf("%s.tmp", input.PackagePath)
-	tmpFile, err := t.os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY, 0644)
 
+	tmpFile, err := t.os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY, 0644)
 	if err != nil {
 		return fmt.Errorf("failed to open file: %w", err)
 	}
 
+	defer tmpFile.Close()
+
 	zipWriter := zip.NewWriter(tmpFile)
+	defer zipWriter.Close()
 
 	err = t.replicateZip(zipReader, zipWriter)
 	if err != nil {
@@ -69,10 +73,6 @@
 		return fmt.Errorf("failed to replicate sinf: %w", err)
 	}
 
-	zipReader.Close()
-	zipWriter.Close()
-	tmpFile.Close()
-
 	err = t.os.Remove(input.PackagePath)
 	if err != nil {
 		return fmt.Errorf("failed to remove original file: %w", err)
@@ -135,22 +135,34 @@
 
 func (t *appstore) replicateZip(src *zip.ReadCloser, dst *zip.Writer) error {
 	for _, file := range src.File {
-		srcFile, err := file.OpenRaw()
+		err := t.copyRawZipFile(file, dst)
 		if err != nil {
-			return fmt.Errorf("failed to open raw file: %w", err)
+			return err
 		}
+	}
 
-		header := file.FileHeader
-		dstFile, err := dst.CreateRaw(&header)
+	return nil
+}
 
-		if err != nil {
-			return fmt.Errorf("failed to create raw file: %w", err)
-		}
+func (*appstore) copyRawZipFile(file *zip.File, dst *zip.Writer) error {
+	srcFile, err := file.OpenRaw()
+	if err != nil {
+		return fmt.Errorf("failed to open raw file: %w", err)
+	}
 
-		_, err = io.Copy(dstFile, srcFile)
-		if err != nil {
-			return fmt.Errorf("failed to copy file: %w", err)
-		}
+	if srcCloser, ok := srcFile.(io.Closer); ok {
+		defer srcCloser.Close()
+	}
+
+	header := file.FileHeader
+	dstFile, err := dst.CreateRaw(&header)
+	if err != nil {
+		return fmt.Errorf("failed to create raw file: %w", err)
+	}
+
+	_, err = io.Copy(dstFile, srcFile)
+	if err != nil {
+		return fmt.Errorf("failed to copy file: %w", err)
 	}
 
 	return nil
@@ -163,6 +175,7 @@
 			if err != nil {
 				return nil, fmt.Errorf("failed to open file: %w", err)
 			}
+			defer src.Close()
 
 			data := new(bytes.Buffer)
 			_, err = io.Copy(data, src)
@@ -192,6 +205,7 @@
 			if err != nil {
 				return nil, fmt.Errorf("failed to open file: %w", err)
 			}
+			defer src.Close()
 
 			data := new(bytes.Buffer)
 			_, err = io.Copy(data, src)