filestore: Close files correctly when concatenating uploads (#1239)

* filestore: Add a method to ensure merged chunk files are properly closed

* Remove unused `ctx` argument

* Handle errors from `src.Close`

---------

Co-authored-by: Marius Kleidl <[email protected]>

Author: nervtech

pkg/filestore/filestore.go

@@ -240,21 +240,28 @@ func (upload *fileUpload) ConcatUploads(ctx context.Context, uploads []handler.U
 	}()
 
 	for _, partialUpload := range uploads {
-		fileUpload := partialUpload.(*fileUpload)
-
-		src, err := os.Open(fileUpload.binPath)
-		if err != nil {
-			return err
-		}
-
-		if _, err := io.Copy(file, src); err != nil {
+		if err := partialUpload.(*fileUpload).appendTo(file); err != nil {
 			return err
 		}
 	}
 
 	return
 }
 
+func (upload *fileUpload) appendTo(file *os.File) error {
+	src, err := os.Open(upload.binPath)
+	if err != nil {
+		return err
+	}
+
+	if _, err := io.Copy(file, src); err != nil {
+		src.Close()
+		return err
+	}
+
+	return src.Close()
+}
+
 func (upload *fileUpload) DeclareLength(ctx context.Context, length int64) error {
 	upload.info.Size = length
 	upload.info.SizeIsDeferred = false