Program: 23452
Project: 23452
Buggy source:
private void checkReference(List<ValidationMessage> errors,String path,Element element,StructureDefinition profile,ElementDefinition container,String parentType,NodeStack stack){
  String ref=element.getNamedChildValue("String_Node_Str");
  if (Utilities.noString(ref)) {
    warning(errors,IssueType.STRUCTURE,element.line(),element.col(),path,!Utilities.noString(element.getNamedChildValue("String_Node_Str")),"String_Node_Str");
    return;
  }
  Element we=resolve(ref,stack);
  String ft;
  if (we != null)   ft=we.getType();
 else   ft=tryParse(ref);
  if (hint(errors,IssueType.STRUCTURE,element.line(),element.col(),path,ft != null,"String_Node_Str")) {
    boolean ok=false;
    CommaSeparatedStringBuilder b=new CommaSeparatedStringBuilder();
    for (    TypeRefComponent type : container.getType()) {
      if (!ok && type.getCode().equals("String_Node_Str")) {
        if (!type.hasProfile() || type.getProfile().equals("String_Node_Str"))         ok=true;
 else {
          String pr=type.getProfile();
          String bt=getBaseType(profile,pr);
          if (rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,bt != null,"String_Node_Str" + pr + "String_Node_Str")) {
            b.append(bt);
            ok=bt.equals(ft);
          }
 else           ok=true;
        }
      }
      if (!ok && type.getCode().equals("String_Node_Str")) {
        ok=true;
      }
    }
    rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,ok,"String_Node_Str" + ft + "String_Node_Str"+ b.toString()+ "String_Node_Str");
  }
}

Fixed version (ground truth):
private void checkReference(List<ValidationMessage> errors,String path,Element element,StructureDefinition profile,ElementDefinition container,String parentType,NodeStack stack){
  String ref=element.getNamedChildValue("String_Node_Str");
  if (Utilities.noString(ref)) {
    warning(errors,IssueType.STRUCTURE,element.line(),element.col(),path,!Utilities.noString(element.getNamedChildValue("String_Node_Str")),"String_Node_Str");
    return;
  }
  String refType=ref.startsWith("String_Node_Str") ? "String_Node_Str" : (localResolve(ref,stack,errors,path) != null ? "String_Node_Str" : "String_Node_Str");
  Element we=resolve(ref,stack,errors,path);
  String ft;
  if (we != null)   ft=we.getType();
 else   ft=tryParse(ref);
  rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,we != null || !refType.equals("String_Node_Str"),"String_Node_Str");
  if (hint(errors,IssueType.STRUCTURE,element.line(),element.col(),path,ft != null,"String_Node_Str")) {
    boolean ok=false;
    CommaSeparatedStringBuilder b=new CommaSeparatedStringBuilder();
    for (    TypeRefComponent type : container.getType()) {
      if (!ok && type.getCode().equals("String_Node_Str")) {
        if (!type.hasProfile() || type.getProfile().equals("String_Node_Str"))         ok=true;
 else {
          String pr=type.getProfile();
          String bt=getBaseType(profile,pr);
          if (rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,bt != null,"String_Node_Str" + pr + "String_Node_Str")) {
            b.append(bt);
            ok=bt.equals(ft);
          }
 else           ok=true;
          if (ok && type.hasAggregation()) {
            rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,!type.getAggregation().equals(ElementDefinition.AggregationMode.CONTAINED) || refType.equals("String_Node_Str"),"String_Node_Str");
            rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,!type.getAggregation().equals(ElementDefinition.AggregationMode.BUNDLED) || refType.equals("String_Node_Str"),"String_Node_Str");
            rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,type.getAggregation().equals(ElementDefinition.AggregationMode.CONTAINED) || !refType.equals("String_Node_Str"),"String_Node_Str");
          }
        }
      }
      if (!ok && type.getCode().equals("String_Node_Str")) {
        ok=true;
      }
    }
    rule(errors,IssueType.STRUCTURE,element.line(),element.col(),path,ok,"String_Node_Str" + ft + "String_Node_Str"+ b.toString()+ "String_Node_Str");
  }
}