Program: 21078
Project: 21078
Buggy source:
public void handleFree(DownloadLink downloadLink) throws Exception {
  String url=null;
  br.setDebug(true);
  for (int i=0; i < 3; i++) {
    requestFileInformation(downloadLink);
    if (downloadLink.getStringProperty("String_Node_Str","String_Node_Str").equalsIgnoreCase("String_Node_Str")) {
      url=br.getRedirectLocation();
    }
 else {
      if (!br.containsHTML("String_Node_Str")) {
        String passCode;
        DownloadLink link=downloadLink;
        Form form=br.getFormbyProperty("String_Node_Str","String_Node_Str");
        if (link.getStringProperty("String_Node_Str",null) == null) {
          passCode=Plugin.getUserInput(null,link);
        }
 else {
          passCode=link.getStringProperty("String_Node_Str",null);
        }
        form.put("String_Node_Str",passCode);
        br.submitForm(form);
        form=br.getFormbyProperty("String_Node_Str","String_Node_Str");
        if (form != null && !br.containsHTML("String_Node_Str")) {
          link.setProperty("String_Node_Str",null);
          throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
        }
 else {
          link.setProperty("String_Node_Str",passCode);
        }
      }
      String qk=null, pk=null, r=null;
      String[] parameters=br.getRegex("String_Node_Str").getRow(0);
      qk=parameters[0];
      pk=parameters[1];
      r=parameters[2];
      br.getPage("String_Node_Str" + qk + "String_Node_Str"+ pk+ "String_Node_Str"+ r);
      String error=br.getRegex("String_Node_Str").getMatch(0);
      if (error != null && !error.trim().equalsIgnoreCase("String_Node_Str"))       throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,30 * 60 * 1000l);
      String js=br.getRegex("String_Node_Str").getMatch(0).trim();
      String vars=br.getRegex("String_Node_Str").getMatch(0).trim();
      Context cx=Context.enter();
      Scriptable scope=cx.initStandardObjects();
      String eval="String_Node_Str" + vars + "String_Node_Str"+ js+ "String_Node_Str";
      Object result=cx.evaluateString(scope,eval,"String_Node_Str",1,null);
      url=Context.toString(result);
    }
  }
  dl=br.openDownload(downloadLink,url,true,0);
  dl.startDownload();
}

Fixed version (ground truth):
public void handleFree(DownloadLink downloadLink) throws Exception {
  String url=null;
  try {
    for (int i=0; i < 3; i++) {
      if (url != null)       break;
      requestFileInformation(downloadLink);
      try {
        Recaptcha rc=new Recaptcha(br);
        Form form=br.getFormbyProperty("String_Node_Str","String_Node_Str");
        String id=br.getRegex("String_Node_Str").getMatch(0);
        if (id != null) {
          rc.setId(id);
          InputField challenge=new InputField("String_Node_Str",null);
          InputField code=new InputField("String_Node_Str",null);
          form.addInputField(challenge);
          form.addInputField(code);
          rc.setForm(form);
          rc.load();
          File cf=rc.downloadCaptcha(getLocalCaptchaFile());
          try {
            String c=getCaptchaCode(cf,downloadLink);
            rc.setCode(c);
          }
 catch (          PluginException e) {
            throw new PluginException(LinkStatus.ERROR_IP_BLOCKED,5 * 60 * 1000l);
          }
        }
      }
 catch (      Exception e) {
      }
      if (downloadLink.getStringProperty("String_Node_Str","String_Node_Str").equalsIgnoreCase("String_Node_Str")) {
        url=br.getRedirectLocation();
      }
 else {
        if (!br.containsHTML("String_Node_Str")) {
          String passCode;
          DownloadLink link=downloadLink;
          Form form=br.getFormbyProperty("String_Node_Str","String_Node_Str");
          if (link.getStringProperty("String_Node_Str",null) == null) {
            passCode=Plugin.getUserInput(null,link);
          }
 else {
            passCode=link.getStringProperty("String_Node_Str",null);
          }
          form.put("String_Node_Str",passCode);
          br.submitForm(form);
          form=br.getFormbyProperty("String_Node_Str","String_Node_Str");
          if (form != null && !br.containsHTML("String_Node_Str")) {
            link.setProperty("String_Node_Str",null);
            throw new PluginException(LinkStatus.ERROR_FATAL,JDL.L("String_Node_Str","String_Node_Str"));
          }
 else {
            link.setProperty("String_Node_Str",passCode);
          }
        }
        String qk=null, pk=null, r=null;
        String[] parameters=br.getRegex("String_Node_Str").getRow(0);
        qk=parameters[0];
        pk=parameters[1];
        r=parameters[2];
        br.getPage("String_Node_Str" + qk + "String_Node_Str"+ pk+ "String_Node_Str"+ r);
        String error=br.getRegex("String_Node_Str").getMatch(0);
        if (error != null && !error.trim().equalsIgnoreCase("String_Node_Str"))         throw new PluginException(LinkStatus.ERROR_TEMPORARILY_UNAVAILABLE,30 * 60 * 1000l);
        String js=br.getRegex("String_Node_Str").getMatch(0).trim();
        String vars=br.getRegex("String_Node_Str").getMatch(0).trim();
        Context cx=Context.enter();
        Scriptable scope=cx.initStandardObjects();
        String eval="String_Node_Str" + vars + "String_Node_Str"+ js+ "String_Node_Str";
        Object result=cx.evaluateString(scope,eval,"String_Node_Str",1,null);
        url=Context.toString(result);
      }
    }
    dl=br.openDownload(downloadLink,url,true,0);
    dl.startDownload();
  }
 catch (  EvaluatorException e) {
    throw new PluginException(LinkStatus.ERROR_RETRY);
  }
}