message: use TFile::Open to access digits file for AliEn compatibility
diff: @@ -83,7 +83,8 @@ TFile* AliTRDdigitsTask::OpenDigitsFile(TString inputfile,
  // open the file
  AliInfo( "opening digits file " + inputfile
  + " with option \"" + opt + "\"");
  - TFile* dfile = new TFile(inputfile, opt);
  + //TFile* dfile = new TFile(inputfile, opt);
  + TFile* dfile = TFile::Open(inputfile, opt);
  if (!dfile) {
  AliWarning("digits file '" + inputfile + "' cannot be opened");
  }
  