Program: 45250
Project: 45250
Buggy source:
public String execute(){
  Date ldt=DownloadNewsTask.getLastDownloadTime();
  _lastDownloadTime=SDF.get().format(ldt);
  String uid=getParam("String_Node_Str");
  if (uid == null) {
    if ((_updatesMostRecent == null) || _lastUpdateTime.before(ldt))     setIssueUpdateLists();
    return "String_Node_Str";
  }
 else {
    _issueOwner=User.getUser(uid);
    if (_issueOwner == null) {
      _log.info("String_Node_Str" + uid);
      return "String_Node_Str";
    }
    String issueName=getParam("String_Node_Str");
    if (issueName == null) {
      return "String_Node_Str";
    }
    _issue=_issueOwner.getIssue(issueName);
    if (_issue == null) {
      _log.info("String_Node_Str" + issueName + "String_Node_Str"+ uid);
      return "String_Node_Str";
    }
    String catId=getParam("String_Node_Str");
    if (catId == null) {
      return "String_Node_Str";
    }
    _cat=_issue.getCategory(Integer.parseInt(catId));
    if (_cat == null) {
      _log.info("String_Node_Str" + catId + "String_Node_Str"+ issueName+ "String_Node_Str"+ uid);
      return "String_Node_Str";
    }
    Category c=_cat;
    LinkedList<Category> ancestors=new LinkedList<Category>();
    while (c != null) {
      c=c.getParent();
      if (c != null)       ancestors.addFirst(c);
    }
    _catAncestors=ancestors;
    if (!_cat.isLeafCategory()) {
      return "String_Node_Str";
    }
 else {
      _numArts=_cat.getNumArticles();
      String startVal=getParam("String_Node_Str");
      if (startVal == null) {
        _start=0;
      }
 else {
        _start=Integer.parseInt(startVal);
        if (_start < 0)         _start=0;
 else         if (_start > _numArts)         _start=_numArts;
      }
      String countVal=getParam("String_Node_Str");
      if (countVal == null) {
        _count=DEF_NUM_ARTS_PER_PAGE;
      }
 else {
        _count=Integer.parseInt(countVal);
        if (_count < MIN_NUM_ARTS_PER_PAGE)         _count=MIN_NUM_ARTS_PER_PAGE;
 else         if (_count > MAX_NUM_ARTS_PER_PAGE)         _count=MAX_NUM_ARTS_PER_PAGE;
      }
      String srcTag=getParam("String_Node_Str");
      Source src=null;
      if ((srcTag != null) && (srcTag != "String_Node_Str"))       src=_issue.getSourceByTag(srcTag);
      Date startDate=null;
      String sdStr=getParam("String_Node_Str");
      if (sdStr != null) {
        try {
          startDate=DATE_PARSER.get().parse(sdStr);
        }
 catch (        Exception e) {
          addActionError(getText("String_Node_Str",sdStr));
          _log.info("String_Node_Str" + sdStr + e);
        }
      }
      Date endDate=null;
      String edStr=getParam("String_Node_Str");
      if (edStr != null) {
        try {
          endDate=DATE_PARSER.get().parse(edStr);
        }
 catch (        Exception e) {
          addActionError(getText("String_Node_Str",edStr));
          _log.info("String_Node_Str" + edStr + e);
        }
      }
      _news=_cat.getNews(startDate,endDate,src,_start,_count);
      return "String_Node_Str";
    }
  }
}

Fixed version (ground truth):
public String execute(){
  Date ldt=DownloadNewsTask.getLastDownloadTime();
  _lastDownloadTime=SDF.get().format(ldt);
  String uid=getParam("String_Node_Str");
  if (uid == null) {
    if ((_updatesMostRecent == null) || _lastUpdateTime.before(ldt))     setIssueUpdateLists();
    return "String_Node_Str";
  }
 else {
    _issueOwner=User.getUser(uid);
    if (_issueOwner == null) {
      _log.info("String_Node_Str" + uid);
      return "String_Node_Str";
    }
    String issueName=getParam("String_Node_Str");
    if (issueName == null) {
      return "String_Node_Str";
    }
    _issue=_issueOwner.getIssue(issueName);
    if (_issue == null) {
      _log.info("String_Node_Str" + issueName + "String_Node_Str"+ uid);
      return "String_Node_Str";
    }
    String catId=getParam("String_Node_Str");
    if (catId == null) {
      return "String_Node_Str";
    }
    _cat=_issue.getCategory(Integer.parseInt(catId));
    if (_cat == null) {
      _log.info("String_Node_Str" + catId + "String_Node_Str"+ issueName+ "String_Node_Str"+ uid);
      return "String_Node_Str";
    }
    Category c=_cat;
    LinkedList<Category> ancestors=new LinkedList<Category>();
    while (c != null) {
      c=c.getParent();
      if (c != null)       ancestors.addFirst(c);
    }
    _catAncestors=ancestors;
    if (!_cat.isLeafCategory()) {
      return "String_Node_Str";
    }
 else {
      _numArts=_cat.getNumArticles();
      String startVal=getParam("String_Node_Str");
      if (startVal == null) {
        _start=0;
      }
 else {
        _start=Integer.parseInt(startVal) - 1;
        if (_start < 0)         _start=0;
 else         if (_start > _numArts)         _start=_numArts;
      }
      String countVal=getParam("String_Node_Str");
      if (countVal == null) {
        _count=DEF_NUM_ARTS_PER_PAGE;
      }
 else {
        _count=Integer.parseInt(countVal);
        if (_count < MIN_NUM_ARTS_PER_PAGE)         _count=MIN_NUM_ARTS_PER_PAGE;
 else         if (_count > MAX_NUM_ARTS_PER_PAGE)         _count=MAX_NUM_ARTS_PER_PAGE;
      }
      String srcTag=getParam("String_Node_Str");
      Source src=null;
      if ((srcTag != null) && (srcTag != "String_Node_Str"))       src=_issue.getSourceByTag(srcTag);
      Date startDate=null;
      String sdStr=getParam("String_Node_Str");
      if (sdStr != null) {
        try {
          startDate=DATE_PARSER.get().parse(sdStr);
        }
 catch (        Exception e) {
          addActionError(getText("String_Node_Str",sdStr));
          _log.info("String_Node_Str" + sdStr + e);
        }
      }
      Date endDate=null;
      String edStr=getParam("String_Node_Str");
      if (edStr != null) {
        try {
          endDate=DATE_PARSER.get().parse(edStr);
        }
 catch (        Exception e) {
          addActionError(getText("String_Node_Str",edStr));
          _log.info("String_Node_Str" + edStr + e);
        }
      }
      _news=_cat.getNews(startDate,endDate,src,_start,_count);
      return "String_Node_Str";
    }
  }
}