Program: 90500
Project: 90500
Buggy source:
@Override public void setup(){
  AbstractConfiguration targetConfiguration=configurations.get(0);
  staffChildConfiguration(targetConfiguration);
  WatchManager watchManager=targetConfiguration.getWatchManager();
  rootNode=targetConfiguration.getRootNode();
  for (  AbstractConfiguration sourceConfiguration : configurations.subList(1,configurations.size())) {
    staffChildConfiguration(sourceConfiguration);
    Node sourceRoot=sourceConfiguration.getRootNode();
    mergeStrategy.mergConfigurations(rootNode,sourceRoot,getPluginManager());
    if (LOGGER.isEnabled(Level.ALL)) {
      StringBuilder sb=new StringBuilder();
      printNodes("String_Node_Str",rootNode,sb);
      System.out.println(sb.toString());
    }
    int monitorInterval=sourceConfiguration.getWatchManager().getIntervalSeconds();
    if (monitorInterval > 0) {
      if (monitorInterval < watchManager.getIntervalSeconds()) {
        watchManager.setIntervalSeconds(monitorInterval);
      }
      WatchManager sourceWatchManager=sourceConfiguration.getWatchManager();
      Map<File,FileWatcher> watchers=sourceWatchManager.getWatchers();
      FileWatcher fileWatcher=new ConfiguratonFileWatcher(this,listeners);
      for (      Map.Entry<File,FileWatcher> entry : watchers.entrySet()) {
        if (entry.getValue() instanceof ConfiguratonFileWatcher) {
          watchManager.watchFile(entry.getKey(),fileWatcher);
        }
      }
    }
  }
  final StatusConfiguration statusConfig=new StatusConfiguration().withVerboseClasses(VERBOSE_CLASSES).withStatus(getDefaultStatus());
  for (  final Map.Entry<String,String> entry : rootNode.getAttributes().entrySet()) {
    final String key=entry.getKey();
    final String value=getStrSubstitutor().replace(entry.getValue());
    if ("String_Node_Str".equalsIgnoreCase(key)) {
      statusConfig.withStatus(value);
    }
 else     if ("String_Node_Str".equalsIgnoreCase(key)) {
      statusConfig.withDestination(value);
    }
 else     if ("String_Node_Str".equalsIgnoreCase(key)) {
      isShutdownHookEnabled=!"String_Node_Str".equalsIgnoreCase(value);
    }
 else     if ("String_Node_Str".equalsIgnoreCase(key)) {
      statusConfig.withVerbosity(value);
    }
 else     if ("String_Node_Str".equalsIgnoreCase(key)) {
      pluginPackages.addAll(Arrays.asList(value.split(Patterns.COMMA_SEPARATOR)));
    }
 else     if ("String_Node_Str".equalsIgnoreCase(key)) {
      setName(value);
    }
  }
  statusConfig.initialize();
}

Fixed version (ground truth):
@Override public void setup(){
  AbstractConfiguration targetConfiguration=configurations.get(0);
  staffChildConfiguration(targetConfiguration);
  WatchManager watchManager=getWatchManager();
  WatchManager targetWatchManager=targetConfiguration.getWatchManager();
  FileWatcher fileWatcher=new ConfiguratonFileWatcher(this,listeners);
  if (targetWatchManager.getIntervalSeconds() > 0) {
    watchManager.setIntervalSeconds(targetWatchManager.getIntervalSeconds());
    Map<File,FileWatcher> watchers=targetWatchManager.getWatchers();
    for (    Map.Entry<File,FileWatcher> entry : watchers.entrySet()) {
      if (entry.getValue() instanceof ConfiguratonFileWatcher) {
        watchManager.watchFile(entry.getKey(),fileWatcher);
      }
    }
  }
  for (  AbstractConfiguration sourceConfiguration : configurations.subList(1,configurations.size())) {
    staffChildConfiguration(sourceConfiguration);
    Node sourceRoot=sourceConfiguration.getRootNode();
    mergeStrategy.mergConfigurations(rootNode,sourceRoot,getPluginManager());
    if (LOGGER.isEnabled(Level.ALL)) {
      StringBuilder sb=new StringBuilder();
      printNodes("String_Node_Str",rootNode,sb);
      System.out.println(sb.toString());
    }
    int monitorInterval=sourceConfiguration.getWatchManager().getIntervalSeconds();
    if (monitorInterval > 0) {
      int currentInterval=watchManager.getIntervalSeconds();
      if (currentInterval <= 0 || monitorInterval < currentInterval) {
        watchManager.setIntervalSeconds(monitorInterval);
      }
      WatchManager sourceWatchManager=sourceConfiguration.getWatchManager();
      Map<File,FileWatcher> watchers=sourceWatchManager.getWatchers();
      for (      Map.Entry<File,FileWatcher> entry : watchers.entrySet()) {
        if (entry.getValue() instanceof ConfiguratonFileWatcher) {
          watchManager.watchFile(entry.getKey(),fileWatcher);
        }
      }
    }
  }
}