Program: 90910
Project: 90910
Buggy source:
/** 
 * Create a File Appender.
 * @param fileName The name and path of the file.
 * @param append "True" if the file should be appended to, "false" if it should be overwritten.The default is "true".
 * @param locking "True" if the file should be locked. The default is "false".
 * @param name The name of the Appender.
 * @param immediateFlush "true" if the contents should be flushed on every write, "false" otherwise. The defaultis "true".
 * @param suppress "true" if exceptions should be hidden from the application, "false" otherwise.The default is "true".
 * @param bufferedIO "true" if I/O should be buffered, "false" otherwise. The default is "true".
 * @param layout The layout to use to format the event. If no layout is provided the default PatternLayoutwill be used.
 * @param filter The filter, if any, to use.
 * @return The FileAppender.
 */
@PluginFactory public static FileAppender createAppender(@PluginAttr("String_Node_Str") String fileName,@PluginAttr("String_Node_Str") String append,@PluginAttr("String_Node_Str") String locking,@PluginAttr("String_Node_Str") String name,@PluginAttr("String_Node_Str") String immediateFlush,@PluginAttr("String_Node_Str") String suppress,@PluginAttr("String_Node_Str") String bufferedIO,@PluginElement("String_Node_Str") Layout layout,@PluginElement("String_Node_Str") Filter filter){
  boolean isAppend=append == null ? true : Boolean.valueOf(append);
  boolean isLocking=locking == null ? false : Boolean.valueOf(locking);
  boolean isBuffered=bufferedIO == null ? true : Boolean.valueOf(bufferedIO);
  ;
  if (isLocking && isBuffered) {
    if (bufferedIO != null) {
      LOGGER.warn("String_Node_Str" + fileName);
    }
    isBuffered=false;
  }
  boolean isFlush=immediateFlush == null ? true : Boolean.valueOf(immediateFlush);
  ;
  boolean handleExceptions=suppress == null ? true : Boolean.valueOf(suppress);
  if (name == null) {
    LOGGER.error("String_Node_Str");
    return null;
  }
  if (fileName == null) {
    LOGGER.error("String_Node_Str" + name);
    return null;
  }
  FileManager manager=FileManager.getFileManager(fileName,isAppend,isLocking,isBuffered);
  if (manager == null) {
    return null;
  }
  if (layout == null) {
    layout=PatternLayout.createLayout(null,null,null,null);
  }
  return new FileAppender(name,layout,filter,manager,fileName,handleExceptions,isFlush);
}

Fixed version (ground truth):
/** 
 * Create a File Appender.
 * @param fileName The name and path of the file.
 * @param append "True" if the file should be appended to, "false" if it should be overwritten.The default is "true".
 * @param locking "True" if the file should be locked. The default is "false".
 * @param name The name of the Appender.
 * @param immediateFlush "true" if the contents should be flushed on every write, "false" otherwise. The defaultis "true".
 * @param suppress "true" if exceptions should be hidden from the application, "false" otherwise.The default is "true".
 * @param bufferedIO "true" if I/O should be buffered, "false" otherwise. The default is "true".
 * @param layout The layout to use to format the event. If no layout is provided the default PatternLayoutwill be used.
 * @param filter The filter, if any, to use.
 * @return The FileAppender.
 */
@PluginFactory public static FileAppender createAppender(@PluginAttr("String_Node_Str") String fileName,@PluginAttr("String_Node_Str") String append,@PluginAttr("String_Node_Str") String locking,@PluginAttr("String_Node_Str") String name,@PluginAttr("String_Node_Str") String immediateFlush,@PluginAttr("String_Node_Str") String suppress,@PluginAttr("String_Node_Str") String bufferedIO,@PluginElement("String_Node_Str") Layout layout,@PluginElement("String_Node_Str") Filter filter){
  boolean isAppend=append == null ? true : Boolean.valueOf(append);
  boolean isLocking=locking == null ? false : Boolean.valueOf(locking);
  boolean isBuffered=bufferedIO == null ? true : Boolean.valueOf(bufferedIO);
  if (isLocking && isBuffered) {
    if (bufferedIO != null) {
      LOGGER.warn("String_Node_Str" + fileName);
    }
    isBuffered=false;
  }
  boolean isFlush=immediateFlush == null ? true : Boolean.valueOf(immediateFlush);
  boolean handleExceptions=suppress == null ? true : Boolean.valueOf(suppress);
  if (name == null) {
    LOGGER.error("String_Node_Str");
    return null;
  }
  if (fileName == null) {
    LOGGER.error("String_Node_Str" + name);
    return null;
  }
  FileManager manager=FileManager.getFileManager(fileName,isAppend,isLocking,isBuffered);
  if (manager == null) {
    return null;
  }
  if (layout == null) {
    layout=PatternLayout.createLayout(null,null,null,null);
  }
  return new FileAppender(name,layout,filter,manager,fileName,handleExceptions,isFlush);
}