Check for existence of xml node before reading it

This avoids breaking the reading of pre-existing TMVA weight files that have been written without this tag.

Author: tmadlener

tmva/tmva/src/VariableNormalizeTransform.cxx

@@ -377,13 +377,15 @@ void TMVA::VariableNormalizeTransform::AttachXMLTo(void* parent)
 
 void TMVA::VariableNormalizeTransform::ReadFromXML( void* trfnode )
 {
-   TString UseOffsetOrNot;
+   fNoOffset = kFALSE;
+   if (gTools.HasAttr(trfnode, "UseOffsetOrNot")) {
+      TString UseOffsetOrNot;
 
-   gTools().ReadAttr(trfnode, "UseOffsetOrNot", UseOffsetOrNot );
-
-   if (UseOffsetOrNot == "NoOffset") fNoOffset = kTRUE;
-   else                              fNoOffset = kFALSE;
+      gTools().ReadAttr(trfnode, "UseOffsetOrNot", UseOffsetOrNot );
 
+      if (UseOffsetOrNot == "NoOffset") fNoOffset = kTRUE;
+      else                              fNoOffset = kFALSE;
+   }
    Bool_t newFormat = kFALSE;
 
    void* inpnode = NULL;