CommandLine: issue with '+' operation on dict

[ZDu-IDM]

            self._options += other._options

in

    if executable and " " in executable:
        other = self.from_string(executable)
        self._executable = other._executable
        if other._args:
            self._args += other._args
        if other.options:
            self._options += other._options

Note: even it is wrong, it didn't cause any issue. This is due to the line is not getting executed in current implementation (other.options is always {})