if oldpath==newpath, then skip mv and just rm oldpath

cmd/main.go

@@ -259,13 +259,27 @@ func _merge(filepath string, mergeTargetFilePath string) error {
 }
 
 func rename(oldpath, newpath string) error {
-	b, err := os.ReadFile(oldpath)
-	if err != nil {
-		return err
-	}
+	if same, err := func() (bool, error) {
+		oldb, err := os.ReadFile(oldpath)
+		if err != nil {
+			return false, err
+		}
 
-	if err := os.WriteFile(newpath, b, os.ModePerm); err != nil {
-		return err
+		newb, err := os.ReadFile(newpath)
+		if err != nil {
+			return false, err
+		}
+
+		return bytes.Equal(oldb, newb), nil
+	}(); err != nil || !same {
+		b, err := os.ReadFile(oldpath)
+		if err != nil {
+			return err
+		}
+
+		if err := os.WriteFile(newpath, b, os.ModePerm); err != nil {
+			return err
+		}
 	}
 
 	return os.Remove(oldpath)