Program: 76006
Project: 76006
Buggy source:
/** 
 * Populate the actor by reading the file specified by the <i>source</i> parameter.  Note that the exception thrown here is a runtime exception, inappropriately.  This is because execution of this method is deferred to the last possible moment, and it is often evaluated in a context where a compile-time exception cannot be thrown.  Thus, extra care should be exercised to provide valid MoML specifications.
 * @exception InvalidStateException If the source cannot be read, or ifan exception is thrown parsing its MoML data.
 */
public void populate() throws InvalidStateException {
  try {
    if (_populating)     return;
    if (_cloning)     return;
    _populating=true;
    if (!_configureDone) {
      _configureDone=true;
      if (_parser == null) {
        _parser=new MoMLParser(workspace());
      }
      _parser.setContext(this);
      if (_source != null && !_source.equals("String_Node_Str")) {
        URL xmlFile=new URL(_base,_source);
        InputStream stream=xmlFile.openStream();
        _parser.parse(xmlFile,stream);
        stream.close();
      }
      if (_text != null && !_text.equals("String_Node_Str")) {
        String trimmed=_text.trim();
        if (trimmed.startsWith("String_Node_Str") && trimmed.endsWith("String_Node_Str")) {
          trimmed=trimmed.substring(2,trimmed.length() - 2).trim();
          if (trimmed.startsWith("String_Node_Str")) {
            trimmed=trimmed.substring(4).trim();
            _parser.parse(_base,trimmed);
          }
        }
 else {
          _parser.parse(_base,_text);
        }
      }
    }
  }
 catch (  Exception ex) {
    MessageHandler.error("String_Node_Str",ex);
    throw new InvalidStateException(this,ex.getMessage());
  }
 finally {
    _populating=false;
  }
}

Fixed version (ground truth):
/** 
 * Populate the actor by reading the file specified by the <i>source</i> parameter.  Note that the exception thrown here is a runtime exception, inappropriately.  This is because execution of this method is deferred to the last possible moment, and it is often evaluated in a context where a compile-time exception cannot be thrown.  Thus, extra care should be exercised to provide valid MoML specifications.
 * @exception InvalidStateException If the source cannot be read, or ifan exception is thrown parsing its MoML data.
 */
public void populate() throws InvalidStateException {
  try {
    if (_populating)     return;
    if (_cloning)     return;
    _populating=true;
    if (!_configureDone) {
      System.out.println("String_Node_Str");
      (new Exception()).printStackTrace();
      _configureDone=true;
      if (_parser == null) {
        _parser=new MoMLParser(workspace());
      }
      _parser.setContext(this);
      if (_source != null && !_source.equals("String_Node_Str")) {
        URL xmlFile=new URL(_base,_source);
        InputStream stream=xmlFile.openStream();
        _parser.parse(xmlFile,stream);
        stream.close();
      }
      if (_text != null && !_text.equals("String_Node_Str")) {
        String trimmed=_text.trim();
        if (trimmed.startsWith("String_Node_Str") && trimmed.endsWith("String_Node_Str")) {
          trimmed=trimmed.substring(2,trimmed.length() - 2).trim();
          if (trimmed.startsWith("String_Node_Str")) {
            trimmed=trimmed.substring(4).trim();
            _parser.parse(_base,trimmed);
          }
        }
 else {
          _parser.parse(_base,_text);
        }
      }
    }
  }
 catch (  Exception ex) {
    MessageHandler.error("String_Node_Str",ex);
    throw new InvalidStateException(this,ex.getMessage());
  }
 finally {
    _populating=false;
  }
}