Program: 61600
Project: 61600
Buggy source:
public TestResult execute(String path,List<String> classesToExecute,int waitTime){
  Process p=null;
  if (!ProjectConfiguration.validJDK())   throw new IllegalArgumentException("String_Node_Str");
  String javaPath=ConfigurationProperties.getProperty("String_Node_Str");
  javaPath+=File.separator + "String_Node_Str";
  String systemcp=System.getProperty("String_Node_Str");
  path=systemcp + File.pathSeparator + path;
  List<String> cls=new ArrayList<>(classesToExecute);
  try {
    List<String> command=new ArrayList<String>();
    command.add(javaPath);
    command.add("String_Node_Str");
    command.add(path);
    command.add(JUnitTestExecutor.class.getName());
    command.addAll(cls);
    ProcessBuilder pb=new ProcessBuilder(command.toArray(new String[command.size()]));
    pb.redirectOutput();
    pb.redirectErrorStream(true);
    long t_start=System.currentTimeMillis();
    p=pb.start();
    String cm2=command.toString().replace("String_Node_Str","String_Node_Str").replace("String_Node_Str","String_Node_Str").replace("String_Node_Str","String_Node_Str");
    log.debug("String_Node_Str" + cm2);
    Worker worker=new Worker(p);
    worker.start();
    worker.join(waitTime);
    long t_end=System.currentTimeMillis();
    int exitvalue=p.exitValue();
    TestResult tr=getTestResult(p);
    p.destroy();
    log.debug("String_Node_Str" + ((t_end - t_start) / 1000) + "String_Node_Str");
    return tr;
  }
 catch (  IllegalThreadStateException|IOException|InterruptedException ex) {
    log.error("String_Node_Str" + ex.getMessage());
    if (p != null)     p.destroy();
    return null;
  }
}

Fixed version (ground truth):
public TestResult execute(String path,List<String> classesToExecute,int waitTime){
  Process p=null;
  if (!ProjectConfiguration.validJDK())   throw new IllegalArgumentException("String_Node_Str");
  String javaPath=ConfigurationProperties.getProperty("String_Node_Str");
  javaPath+=File.separator + "String_Node_Str";
  String systemcp=System.getProperty("String_Node_Str");
  path=systemcp + File.pathSeparator + path;
  List<String> cls=new ArrayList<>(classesToExecute);
  try {
    List<String> command=new ArrayList<String>();
    command.add(javaPath);
    command.add("String_Node_Str");
    command.add(path);
    command.add(JUnitTestExecutor.class.getName());
    command.addAll(cls);
    ProcessBuilder pb=new ProcessBuilder(command.toArray(new String[command.size()]));
    pb.redirectOutput();
    pb.redirectErrorStream(true);
    long t_start=System.currentTimeMillis();
    p=pb.start();
    String cm2=command.toString().replace("String_Node_Str","String_Node_Str").replace("String_Node_Str","String_Node_Str").replace("String_Node_Str","String_Node_Str");
    log.debug("String_Node_Str" + cm2);
    Worker worker=new Worker(p);
    worker.start();
    worker.join(waitTime);
    long t_end=System.currentTimeMillis();
    int exitvalue=p.exitValue();
    TestResult tr=getTestResult(p);
    p.destroy();
    log.debug("String_Node_Str" + ((t_end - t_start) / 1000) + "String_Node_Str");
    return tr;
  }
 catch (  IllegalArgumentException|IOException|InterruptedException ex) {
    log.error("String_Node_Str" + ex.getMessage());
    if (p != null)     p.destroy();
    return null;
  }
}