Program: 61620
Project: 61620
Buggy source:
@Override public GraphTextWriter appendTo(GraphTextWriter writer,LocalData localData) throws InterruptedException {
  if (assignment instanceof SetLocalAVM2Item) {
    SetLocalAVM2Item lti=(SetLocalAVM2Item)assignment;
    String localName=localRegName(localData.localRegNames,lti.regIndex);
    srcData.put("String_Node_Str",localName);
    srcData.put("String_Node_Str","String_Node_Str");
    GraphTargetItem coerType=TypeItem.UNBOUNDED;
    if (lti.value instanceof CoerceAVM2Item) {
      coerType=((CoerceAVM2Item)lti.value).typeObj;
    }
    if (lti.value instanceof ConvertAVM2Item) {
      coerType=((ConvertAVM2Item)lti.value).type;
    }
    writer.append("String_Node_Str");
    writer.append(localName);
    writer.append("String_Node_Str");
    coerType.appendTo(writer,localData);
    writer.append("String_Node_Str");
    return lti.value.toString(writer,localData);
  }
  if (assignment instanceof SetSlotAVM2Item) {
    SetSlotAVM2Item ssti=(SetSlotAVM2Item)assignment;
    srcData.put("String_Node_Str",ssti.getNameAsStr(localData));
    srcData.put("String_Node_Str","String_Node_Str");
    writer.append("String_Node_Str");
    ssti.getName(writer,localData);
    writer.append("String_Node_Str");
    type.appendTo(writer,localData);
    writer.append("String_Node_Str");
    return ssti.value.toString(writer,localData);
  }
  writer.append("String_Node_Str");
  return assignment.toString(writer,localData);
}

Fixed version (ground truth):
@Override public GraphTextWriter appendTo(GraphTextWriter writer,LocalData localData) throws InterruptedException {
  if (assignment instanceof LocalRegAVM2Item) {
    LocalRegAVM2Item lti=(LocalRegAVM2Item)assignment;
    String localName=localRegName(localData.localRegNames,lti.regIndex);
    srcData.put("String_Node_Str",localName);
    srcData.put("String_Node_Str","String_Node_Str");
    writer.append("String_Node_Str");
    writer.append(localName);
    return writer;
  }
  if (assignment instanceof GetSlotAVM2Item) {
    GetSlotAVM2Item sti=(GetSlotAVM2Item)assignment;
    srcData.put("String_Node_Str",sti.getNameAsStr(localData));
    srcData.put("String_Node_Str","String_Node_Str");
    writer.append("String_Node_Str");
    sti.getName(writer,localData);
    return writer;
  }
  if (assignment instanceof SetLocalAVM2Item) {
    SetLocalAVM2Item lti=(SetLocalAVM2Item)assignment;
    String localName=localRegName(localData.localRegNames,lti.regIndex);
    srcData.put("String_Node_Str",localName);
    srcData.put("String_Node_Str","String_Node_Str");
    GraphTargetItem coerType=TypeItem.UNBOUNDED;
    if (lti.value instanceof CoerceAVM2Item) {
      coerType=((CoerceAVM2Item)lti.value).typeObj;
    }
    if (lti.value instanceof ConvertAVM2Item) {
      coerType=((ConvertAVM2Item)lti.value).type;
    }
    writer.append("String_Node_Str");
    writer.append(localName);
    writer.append("String_Node_Str");
    coerType.appendTo(writer,localData);
    writer.append("String_Node_Str");
    return lti.value.toString(writer,localData);
  }
  if (assignment instanceof SetSlotAVM2Item) {
    SetSlotAVM2Item ssti=(SetSlotAVM2Item)assignment;
    srcData.put("String_Node_Str",ssti.getNameAsStr(localData));
    srcData.put("String_Node_Str","String_Node_Str");
    writer.append("String_Node_Str");
    ssti.getName(writer,localData);
    writer.append("String_Node_Str");
    type.appendTo(writer,localData);
    writer.append("String_Node_Str");
    return ssti.value.toString(writer,localData);
  }
  writer.append("String_Node_Str");
  return assignment.toString(writer,localData);
}