Program: 13228
Project: 13228
Buggy source:
@Override public Trigger acquireNextTrigger(SchedulingContext context,long noLaterThan) throws JobPersistenceException {
synchronized (lock) {
    Trigger trigger=null;
    WaitingTriggers waitingTriggers=null;
    while (trigger == null) {
      try {
        waitingTriggers=getWaitingTriggers();
        trigger=waitingTriggers.getTriggers().first();
      }
 catch (      NoSuchElementException e1) {
        logger.debug("String_Node_Str");
        return null;
      }
      if (trigger == null) {
        logger.debug("String_Node_Str");
        return null;
      }
      Date nextFireTime=trigger.getNextFireTime();
      if (nextFireTime == null) {
        logger.debug("String_Node_Str");
        removeWaitingTrigger(trigger);
        trigger=null;
        continue;
      }
      if (!removeWaitingTrigger(trigger)) {
        trigger=null;
        continue;
      }
      TriggerWrapper tw=getTriggerWrapper(trigger.getGroup(),trigger.getName());
      if (hasTriggerMisfired(trigger)) {
        logger.debug("String_Node_Str");
        processTriggerMisfired(tw);
        if (trigger.getNextFireTime() != null) {
          addWaitingTrigger(trigger);
        }
        trigger=null;
        continue;
      }
      if (noLaterThan > 0) {
        if (nextFireTime.getTime() > noLaterThan) {
          addWaitingTrigger(trigger);
          return null;
        }
      }
      tw.setAcquired(true);
      trigger.setFireInstanceId(getFiredTriggerRecordId());
      try {
        tw.updateTrigger(trigger);
      }
 catch (      Exception e) {
        logger.warn("String_Node_Str",e);
        throw new JobPersistenceException("String_Node_Str",e);
      }
      updateTriggerInRepo(trigger.getGroup(),trigger.getName(),tw,tw.getRevision());
      addAcquiredTrigger(trigger,instanceId);
      logger.debug("String_Node_Str",new Object[]{trigger.getName(),trigger.getNextFireTime()});
      return (Trigger)trigger.clone();
    }
    logger.debug("String_Node_Str");
    return null;
  }
}

Fixed version (ground truth):
@Override public Trigger acquireNextTrigger(SchedulingContext context,long noLaterThan) throws JobPersistenceException {
synchronized (lock) {
    logger.debug("String_Node_Str");
    Trigger trigger=null;
    WaitingTriggers waitingTriggers=null;
    while (trigger == null) {
      try {
        waitingTriggers=getWaitingTriggers();
        trigger=waitingTriggers.getTriggers().first();
      }
 catch (      NoSuchElementException e1) {
        logger.debug("String_Node_Str");
        return null;
      }
      if (trigger == null) {
        logger.debug("String_Node_Str");
        return null;
      }
      Date nextFireTime=trigger.getNextFireTime();
      if (nextFireTime == null) {
        logger.debug("String_Node_Str");
        removeWaitingTrigger(trigger);
        trigger=null;
        continue;
      }
      if (!removeWaitingTrigger(trigger)) {
        trigger=null;
        continue;
      }
      TriggerWrapper tw=getTriggerWrapper(trigger.getGroup(),trigger.getName());
      if (hasTriggerMisfired(trigger)) {
        logger.debug("String_Node_Str");
        processTriggerMisfired(tw);
        if (trigger.getNextFireTime() != null) {
          addWaitingTrigger(trigger);
        }
        trigger=null;
        continue;
      }
      if (noLaterThan > 0) {
        if (nextFireTime.getTime() > noLaterThan) {
          addWaitingTrigger(trigger);
          return null;
        }
      }
      tw.setAcquired(true);
      trigger.setFireInstanceId(getFiredTriggerRecordId());
      try {
        tw.updateTrigger(trigger);
      }
 catch (      Exception e) {
        logger.warn("String_Node_Str",e);
        throw new JobPersistenceException("String_Node_Str",e);
      }
      updateTriggerInRepo(trigger.getGroup(),trigger.getName(),tw,tw.getRevision());
      addAcquiredTrigger(trigger,instanceId);
      logger.debug("String_Node_Str",new Object[]{trigger.getName(),trigger.getNextFireTime()});
      return (Trigger)trigger.clone();
    }
    logger.debug("String_Node_Str");
    return null;
  }
}