Returns "" rather than "null" on missing value
authorNiels Erik G. Nielsen <nielserik@indexdata.com>
Thu, 7 May 2015 10:31:26 +0000 (12:31 +0200)
committerNiels Erik G. Nielsen <nielserik@indexdata.com>
Thu, 7 May 2015 10:31:26 +0000 (12:31 +0200)
commit5211ca6a4525491499ac763373a703e35bdce37f
treef3aefed4fd5c80c09f7a292cebe28883a9ebeba7
parentf969f221326787617bd4a8766bed1942d010eae0
Returns "" rather than "null" on missing value

.. in SearchCommand.filter expression ('pz:id='). Outcome would be
   the same ('no targets') unless there was a target with the ID "null"
src/main/java/com/indexdata/mkjsf/pazpar2/commands/Expression.java