o RooAbsTestStatistic

    - Add virtual function processEmptyDatasets that controls
      processing of empty datasets in simultaneous mode. The default
      implementation returns kTRUE

    - Modify logic of processing in simultaneous mode so that empty
      data sets also get a NLL calculator if processEmptyDatasets()
      returns kTRUE. This is necessary in cases where an extended likelihood
      term is defined that can return a non-zero NLL even if there is no
      associated data. (Fixes bug #38932)


git-svn-id: http://root.cern.ch/svn/root/trunk@24886 27541ba8-7e3a-0410-8455-c3a389f83636