config: reject remote names starting with a dash. (#4261)

fs/fspath/path.go

@@ -19,6 +19,7 @@ const (
 var (
 	errInvalidCharacters = errors.New("config name contains invalid characters - may only contain 0-9, A-Z ,a-z ,_ , - and space ")
 	errCantBeEmpty       = errors.New("can't use empty string as a path")
+	errCantStartWithDash = errors.New("config name starts with -")
 
 	// urlMatcher is a pattern to match an rclone URL
 	// note that this matches invalid remoteNames
@@ -36,6 +37,10 @@ func CheckConfigName(configName string) error {
 	if !configNameMatcher.MatchString(configName) {
 		return errInvalidCharacters
 	}
+	// Reject configName, if it starts with -, complicates usage. (#4261)
+	if strings.HasPrefix(configName, "-") {
+		return errCantStartWithDash
+	}
 	return nil
 }
 

fs/fspath/path_test.go

@@ -23,6 +23,9 @@ func TestCheckConfigName(t *testing.T) {
 		{"rem\\ote", errInvalidCharacters},
 		{"[remote", errInvalidCharacters},
 		{"*", errInvalidCharacters},
+		{"-remote", errCantStartWithDash},
+		{"r-emote-", nil},
+		{"_rem_ote_", nil},
 	} {
 		got := CheckConfigName(test.in)
 		assert.Equal(t, test.want, got, test.in)