Program: 94080
Project: 94080
Buggy source:
public void onPlayerCommandPreprocess(PlayerChatEvent event){
  String[] split=event.getMessage().split("String_Node_Str");
  Player player=event.getPlayer();
  if (split[0].equals("String_Node_Str")) {
    if (!this.plugin.isRegistered(player.getName()))     Messages.SendMessage("String_Node_Str",player,null);
 else     if (AuthDB.isAuthorized(player.getEntityId())) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (split.length == 3) {
      if (this.plugin.checkPassword(split[1],split[2])) {
        ItemStack[] inv=this.plugin.getInventory(player.getName());
        if (inv != null) {
          player.getInventory().setContents(inv);
        }
        this.plugin.authorize(player.getEntityId());
        long timestamp=System.currentTimeMillis() / 1000;
        this.plugin.db2.put(Encryption.md5(player.getName() + Util.GetIP(player)),"String_Node_Str" + timestamp);
        if (Config.debug_enable)         Util.Debug("String_Node_Str" + player.getName());
        Messages.SendMessage("String_Node_Str",player,null);
      }
 else       if (Config.password_kick) {
        Messages.SendMessage("String_Node_Str",player,null);
      }
    }
 else     if (split.length < 2) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (this.plugin.checkPassword(player.getName(),split[1])) {
      ItemStack[] inv=this.plugin.getInventory(player.getName());
      if (inv != null) {
        player.getInventory().setContents(inv);
      }
      this.plugin.authorize(player.getEntityId());
      long timestamp=System.currentTimeMillis() / 1000;
      this.plugin.db2.put(Encryption.md5(player.getName() + Util.GetIP(player)),"String_Node_Str" + timestamp);
      if (Config.debug_enable)       Util.Debug("String_Node_Str" + player.getName());
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (Config.password_kick) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
    if (Config.debug_enable)     Util.Debug(player.getName() + "String_Node_Str");
    event.setMessage("String_Node_Str");
    event.setCancelled(true);
  }
 else   if (split[0].equals("String_Node_Str")) {
    if (!Config.register_enabled)     Messages.SendMessage("String_Node_Str",player,null);
 else     if (this.plugin.isRegistered(player.getName()))     Messages.SendMessage("String_Node_Str",player,null);
 else     if (split.length < 2) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (split.length < 3)     Messages.SendMessage("String_Node_Str",player,null);
 else     if ((split.length >= 3) && (!this.plugin.checkEmail(split[2])))     Messages.SendMessage("String_Node_Str",player,null);
 else {
      try {
        if (split.length >= 3)         this.plugin.register(player.getName(),split[1],split[2],Util.GetIP(player));
 else         this.plugin.register(player.getName(),split[1],Util.GetIP(player));
        ItemStack[] inv=this.plugin.getInventory(player.getName());
        if (inv != null)         player.getInventory().setContents(inv);
        Messages.SendMessage("String_Node_Str",player,null);
        this.plugin.authorize(player.getEntityId());
      }
 catch (      IOException e) {
        Messages.SendMessage("String_Node_Str",player,null);
        e.printStackTrace();
      }
catch (      SQLException e) {
        Messages.SendMessage("String_Node_Str",player,null);
        e.printStackTrace();
      }
    }
    if (Config.debug_enable)     Util.Debug(player.getName() + "String_Node_Str");
    event.setMessage("String_Node_Str");
    event.setCancelled(true);
  }
 else   if (!AuthDB.isAuthorized(player.getEntityId())) {
    event.setMessage("String_Node_Str");
    event.setCancelled(true);
  }
}

Fixed version (ground truth):
public void onPlayerCommandPreprocess(PlayerChatEvent event){
  String[] split=event.getMessage().split("String_Node_Str");
  Player player=event.getPlayer();
  if (split[0].equals("String_Node_Str")) {
    if (!this.plugin.isRegistered(player.getName()))     Messages.SendMessage("String_Node_Str",player,null);
 else     if (AuthDB.isAuthorized(player.getEntityId())) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (split.length == 3) {
      if (this.plugin.checkPassword(split[1],split[2])) {
        ItemStack[] inv=this.plugin.getInventory(player.getName());
        if (inv != null) {
          player.getInventory().setContents(inv);
        }
        this.plugin.authorize(player.getEntityId());
        long timestamp=System.currentTimeMillis() / 1000;
        this.plugin.db2.put(Encryption.md5(player.getName() + Util.GetIP(player)),"String_Node_Str" + timestamp);
        if (Config.debug_enable)         Util.Debug("String_Node_Str" + player.getName());
        Messages.SendMessage("String_Node_Str",player,null);
      }
 else       if (Config.password_kick) {
        Messages.SendMessage("String_Node_Str",player,null);
      }
    }
 else     if (split.length < 2) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (this.plugin.checkPassword(player.getName(),split[1])) {
      ItemStack[] inv=this.plugin.getInventory(player.getName());
      if (inv != null) {
        player.getInventory().setContents(inv);
      }
      this.plugin.authorize(player.getEntityId());
      long timestamp=System.currentTimeMillis() / 1000;
      this.plugin.db2.put(Encryption.md5(player.getName() + Util.GetIP(player)),"String_Node_Str" + timestamp);
      if (Config.debug_enable)       Util.Debug("String_Node_Str" + player.getName());
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (Config.password_kick) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
    if (Config.debug_enable)     Util.Debug(player.getName() + "String_Node_Str");
    event.setMessage("String_Node_Str");
    event.setCancelled(true);
  }
 else   if (split[0].equals("String_Node_Str")) {
    if (!Config.register_enabled)     Messages.SendMessage("String_Node_Str",player,null);
 else     if (this.plugin.isRegistered(player.getName()))     Messages.SendMessage("String_Node_Str",player,null);
 else     if (split.length < 2) {
      Messages.SendMessage("String_Node_Str",player,null);
    }
 else     if (split.length < 3)     Messages.SendMessage("String_Node_Str",player,null);
 else     if ((split.length >= 3) && (!this.plugin.checkEmail(split[2])))     Messages.SendMessage("String_Node_Str",player,null);
 else {
      try {
        if (split.length >= 3)         this.plugin.register(player.getName(),split[1],split[2],Util.GetIP(player));
 else         this.plugin.register(player.getName(),split[1],Util.GetIP(player));
        ItemStack[] inv=this.plugin.getInventory(player.getName());
        if (inv != null)         player.getInventory().setContents(inv);
        long timestamp=System.currentTimeMillis() / 1000;
        this.plugin.db2.put(Encryption.md5(player.getName() + Util.GetIP(player)),"String_Node_Str" + timestamp);
        if (Config.debug_enable)         Util.Debug("String_Node_Str" + player.getName());
        Messages.SendMessage("String_Node_Str",player,null);
        this.plugin.authorize(player.getEntityId());
      }
 catch (      IOException e) {
        Messages.SendMessage("String_Node_Str",player,null);
        e.printStackTrace();
      }
catch (      SQLException e) {
        Messages.SendMessage("String_Node_Str",player,null);
        e.printStackTrace();
      }
    }
    if (Config.debug_enable)     Util.Debug(player.getName() + "String_Node_Str");
    event.setMessage("String_Node_Str");
    event.setCancelled(true);
  }
 else   if (!AuthDB.isAuthorized(player.getEntityId())) {
    event.setMessage("String_Node_Str");
    event.setCancelled(true);
  }
}