+const incompleteFileSuffix = ".incomplete"
+
+// effectiveFile wraps os.Open to check for the presence of a partial file transfer as a fallback
+func effectiveFile(filePath string) (*os.File, error) {
+ file, err := os.Open(filePath)
+ if err != nil && !errors.Is(err, fs.ErrNotExist) {
+ return nil, err
+ }
+
+ if errors.Is(err, fs.ErrNotExist) {
+ file, err = os.OpenFile(filePath+incompleteFileSuffix, os.O_APPEND|os.O_WRONLY, 0644)
+ if err != nil {
+ return nil, err
+ }