Program: 144801
Project: 144801
Buggy source:
/** 
 * Identify the itemset in the backend model, and create a set of SelectChoice  objects at the current question reference based on the data in the model. Will modify the itemset binding to contain the relevant choices 
 * @param itemset The binding for an itemset, where the choices will be populated
 * @param curQRef A reference to the current question's element, which will beused to determine the values to be chosen from.
 */
public void populateDynamicChoices(ItemsetBinding itemset,TreeReference curQRef){
  Vector<SelectChoice> choices=new Vector<SelectChoice>();
  Vector<TreeReference> matches=itemset.nodesetExpr.evalNodeset(this.getMainInstance(),new EvaluationContext(exprEvalContext,itemset.contextRef.contextualize(curQRef)));
  DataInstance fi=null;
  if (itemset.nodesetRef.getInstanceName() != null) {
    fi=getNonMainInstance(itemset.nodesetRef.getInstanceName());
    if (fi == null) {
      System.out.println("String_Node_Str" + itemset.nodesetRef.getInstanceName() + "String_Node_Str");
    }
  }
 else {
    fi=getMainInstance();
  }
  for (int i=0; i < matches.size(); i++) {
    TreeReference item=matches.elementAt(i);
    String label=itemset.labelExpr.evalReadable(fi,new EvaluationContext(exprEvalContext,item));
    String value=null;
    TreeElement copyNode=null;
    if (itemset.copyMode) {
      copyNode=this.getMainInstance().resolveReference(itemset.copyRef.contextualize(item));
    }
    if (itemset.valueRef != null) {
      value=itemset.valueExpr.evalReadable(fi,new EvaluationContext(exprEvalContext,item));
    }
    SelectChoice choice=new SelectChoice(label,value != null ? value : "String_Node_Str" + i,itemset.labelIsItext);
    choice.setIndex(i);
    if (itemset.copyMode)     choice.copyNode=copyNode;
    choices.addElement(choice);
  }
  if (choices.size() == 0) {
    System.out.println("String_Node_Str" + itemset.nodesetRef + "String_Node_Str");
  }
  itemset.setChoices(choices,this.getLocalizer());
}

Fixed version (ground truth):
/** 
 * Identify the itemset in the backend model, and create a set of SelectChoice  objects at the current question reference based on the data in the model. Will modify the itemset binding to contain the relevant choices 
 * @param itemset The binding for an itemset, where the choices will be populated
 * @param curQRef A reference to the current question's element, which will beused to determine the values to be chosen from.
 */
public void populateDynamicChoices(ItemsetBinding itemset,TreeReference curQRef){
  Vector<SelectChoice> choices=new Vector<SelectChoice>();
  Vector<TreeReference> matches=itemset.nodesetExpr.evalNodeset(this.getMainInstance(),new EvaluationContext(exprEvalContext,itemset.contextRef.contextualize(curQRef)));
  DataInstance fi=null;
  if (itemset.nodesetRef.getInstanceName() != null) {
    fi=getNonMainInstance(itemset.nodesetRef.getInstanceName());
    if (fi == null) {
      System.out.println("String_Node_Str" + itemset.nodesetRef.getInstanceName() + "String_Node_Str");
    }
  }
 else {
    fi=getMainInstance();
  }
  if (matches == null) {
    throw new XPathException("String_Node_Str" + itemset.nodesetRef.getInstanceName());
  }
  for (int i=0; i < matches.size(); i++) {
    TreeReference item=matches.elementAt(i);
    String label=itemset.labelExpr.evalReadable(fi,new EvaluationContext(exprEvalContext,item));
    String value=null;
    TreeElement copyNode=null;
    if (itemset.copyMode) {
      copyNode=this.getMainInstance().resolveReference(itemset.copyRef.contextualize(item));
    }
    if (itemset.valueRef != null) {
      value=itemset.valueExpr.evalReadable(fi,new EvaluationContext(exprEvalContext,item));
    }
    SelectChoice choice=new SelectChoice(label,value != null ? value : "String_Node_Str" + i,itemset.labelIsItext);
    choice.setIndex(i);
    if (itemset.copyMode)     choice.copyNode=copyNode;
    choices.addElement(choice);
  }
  if (choices.size() == 0) {
    System.out.println("String_Node_Str" + itemset.nodesetRef + "String_Node_Str");
  }
  itemset.setChoices(choices,this.getLocalizer());
}