Attempt to workaround problem reported about empty plc.xml after unrelated crash. Now, if etree model is corrupted in a way tostring() would generate an empty string, exception prevents saving.
# -*- coding: utf-8 -*-
# See COPYING.Runtime file for copyrights details.
def _(x):
"""No translation"""
return x
Broken = _("Broken")
Started = _("Started")
Stopped = _("Stopped")
Disconnected = _("Disconnected")
Empty = _("Empty")