Transform empty string to something different

How can I transform an empty string to something different using a map-file?

The map-file looks like, but doesn’t work:
’’=undefiniert
=undefiniert

Logfile shows following error:
Could not transform ‘’ with the file ‘anaus.map’ : Target value not found in map for ‘’

hmm. How do you get a empty string in the first place? :wink:
Usually there is “NULL” or “UNDEF”, which works in map-transformation.
You could try writing a rule changing ‘’ to UNDEF or something - or working on not having an empty string somehow… :stuck_out_tongue_winking_eye: