Program: 94022
Project: 94022
Buggy source:
public void onPlayerCommandPreprocess(PlayerCommandPreprocessEvent event){
  long start=Util.timeMS();
  String Contrib=event.getMessage();
  Contrib=Contrib.replaceAll("String_Node_Str","String_Node_Str");
  if (!ZBukkitContrib.checkCommand(Contrib)) {
    String[] split=event.getMessage().split("String_Node_Str");
    Player player=event.getPlayer();
    if (split[0].equalsIgnoreCase(Config.commands_login) || split[0].equalsIgnoreCase(Config.aliases_login)) {
      if (ZPermissions.isAllowed(player,Permission.command_login)) {
        if (this.plugin.isRegistered("String_Node_Str",player.getName()) == false || this.plugin.isRegistered("String_Node_Str",Util.checkOtherName(player.getName())) == false) {
          Messages.sendMessage(Message.login_notregistered,player,null);
        }
 else         if (plugin.isAuthorized(player)) {
          Messages.sendMessage(Message.login_authorized,player,null);
        }
 else         if (split.length < 2) {
          Messages.sendMessage(Message.login_usage,player,null);
        }
 else         if (this.plugin.checkPassword(player.getName(),split[1])) {
          Processes.Login(player);
          Messages.sendMessage(Message.login_success,player,null);
        }
 else {
          Messages.sendMessage(Message.login_failure,player,null);
        }
        Util.logging.Debug(player.getName() + "String_Node_Str");
        event.setMessage(Config.commands_login + "String_Node_Str");
        event.setCancelled(true);
      }
 else {
        Messages.sendMessage(Message.protection_denied,player,null);
      }
    }
 else     if (split[0].equalsIgnoreCase(Config.commands_link) || split[0].equalsIgnoreCase(Config.aliases_link)) {
      if (Config.link_enabled) {
        if (ZPermissions.isAllowed(player,Permission.command_link)) {
          if (split.length == 3) {
            if (!player.getName().equals(split[1])) {
              if (Util.checkOtherName(player.getName()).equals(player.getName())) {
                EBean eBeanClass=EBean.checkPlayer(split[1],true);
                String linkedname=eBeanClass.getLinkedname();
                if (linkedname != null) {
                  Messages.sendMessage(Message.link_duplicate,player,null);
                }
 else                 if (this.plugin.checkPassword(split[1],split[2])) {
                  Processes.Link(player,split[1]);
                  Messages.sendMessage(Message.link_success,player,null);
                }
 else {
                  Messages.sendMessage(Message.link_failure,player,null);
                }
              }
 else {
                Messages.sendMessage(Message.link_exists,player,null);
              }
            }
 else {
              Messages.sendMessage(Message.link_invaliduser,player,null);
            }
          }
 else {
            Messages.sendMessage(Message.link_usage,player,null);
          }
          Util.logging.Debug(player.getName() + "String_Node_Str");
          event.setMessage(Config.commands_link + "String_Node_Str");
          event.setCancelled(true);
        }
 else {
          Messages.sendMessage(Message.protection_denied,player,null);
        }
      }
    }
 else     if (split[0].equalsIgnoreCase(Config.commands_unlink) || split[0].equalsIgnoreCase(Config.aliases_unlink)) {
      if (Config.unlink_enabled) {
        if (ZPermissions.isAllowed(player,Permission.command_unlink)) {
          if (split.length == 3) {
            if (Util.checkOtherName(player.getName()).equals(player.getDisplayName())) {
              EBean eBeanClass=EBean.checkPlayer(player,true);
              String linkedname=eBeanClass.getLinkedname();
              if (linkedname.equals(split[1])) {
                if (this.plugin.checkPassword(split[1],split[2])) {
                  Processes.Unlink(player,split[1]);
                  Messages.sendMessage(Message.unlink_success,player,null);
                }
 else {
                  Messages.sendMessage(Message.unlink_invalidpass,player,null);
                }
              }
 else {
                Messages.sendMessage(Message.unlink_invaliduser,player,null);
              }
            }
 else {
              Messages.sendMessage(Message.unlink_nonexist,player,null);
            }
          }
 else {
            Messages.sendMessage(Message.unlink_usage,player,null);
          }
          Util.logging.Debug(player.getName() + "String_Node_Str");
          event.setMessage(Config.commands_unlink + "String_Node_Str");
          event.setCancelled(true);
        }
 else {
          Messages.sendMessage(Message.protection_denied,player,null);
        }
      }
    }
 else     if (split[0].equalsIgnoreCase(Config.commands_register) || split[0].equalsIgnoreCase(Config.aliases_register)) {
      if (ZPermissions.isAllowed(player,Permission.command_register)) {
        Boolean email=true;
        if (Config.custom_enabled) {
          email=Config.custom_emailrequired;
        }
        if (Config.custom_emailfield == null || Config.custom_emailfield == "String_Node_Str") {
          email=false;
        }
        if (!Config.register_enabled) {
          Messages.sendMessage(Message.register_disabled,player,null);
        }
 else         if (this.plugin.isRegistered("String_Node_Str",player.getName()) || this.plugin.isRegistered("String_Node_Str",Util.checkOtherName(player.getName()))) {
          Messages.sendMessage(Message.register_exists,player,null);
        }
 else         if (split.length < 2) {
          Messages.sendMessage(Message.register_usage,player,null);
        }
 else         if (split.length < 3 && email) {
          Messages.sendMessage(Message.email_required,player,null);
        }
 else         if ((split.length >= 3 && email) && (!this.plugin.checkEmail(split[2]))) {
          Messages.sendMessage(Message.email_invalid,player,null);
        }
 else {
          try {
            if (split.length >= 3 || (!email && split.length >= 2)) {
              String themail=null;
              if (!email) {
                themail=null;
              }
 else {
                themail=split[2];
              }
              if (this.plugin.register(player,split[1],themail,Util.craftFirePlayer.getIP(player))) {
                if (Processes.Login(player)) {
                  Messages.sendMessage(Message.register_success,player,null);
                }
 else {
                  Messages.sendMessage(Message.register_failure,player,null);
                  Util.logging.Debug("String_Node_Str");
                }
              }
            }
          }
 catch (          IOException e) {
            Messages.sendMessage(Message.register_failure,player,null);
            Util.logging.StackTrace(e.getStackTrace(),Thread.currentThread().getStackTrace()[1].getMethodName(),Thread.currentThread().getStackTrace()[1].getLineNumber(),Thread.currentThread().getStackTrace()[1].getClassName(),Thread.currentThread().getStackTrace()[1].getFileName());
          }
catch (          SQLException e) {
            Messages.sendMessage(Message.register_failure,player,null);
            Util.logging.StackTrace(e.getStackTrace(),Thread.currentThread().getStackTrace()[1].getMethodName(),Thread.currentThread().getStackTrace()[1].getLineNumber(),Thread.currentThread().getStackTrace()[1].getClassName(),Thread.currentThread().getStackTrace()[1].getFileName());
          }
        }
        Util.logging.Debug(player.getName() + "String_Node_Str");
        event.setMessage(Config.commands_register + "String_Node_Str");
        event.setCancelled(true);
      }
 else {
        Messages.sendMessage(Message.protection_denied,player,null);
      }
    }
 else     if (!plugin.isAuthorized(player)) {
      if (!checkGuest(player,Config.guests_commands)) {
        event.setMessage("String_Node_Str");
        event.setCancelled(true);
      }
    }
  }
 else {
    Util.logging.Debug("String_Node_Str" + event.getMessage());
  }
  long stop=Util.timeMS();
  Util.logging.timeUsage(stop - start,"String_Node_Str");
}

Fixed version (ground truth):
public void onPlayerCommandPreprocess(PlayerCommandPreprocessEvent event){
  long start=Util.timeMS();
  String Contrib=event.getMessage();
  Contrib=Contrib.replaceAll("String_Node_Str","String_Node_Str");
  if (!ZBukkitContrib.checkCommand(Contrib)) {
    String[] split=event.getMessage().split("String_Node_Str");
    Player player=event.getPlayer();
    if (split[0].equalsIgnoreCase(Config.commands_login) || split[0].equalsIgnoreCase(Config.aliases_login)) {
      if (ZPermissions.isAllowed(player,Permission.command_login)) {
        if (this.plugin.isRegistered("String_Node_Str",player.getName()) == false || this.plugin.isRegistered("String_Node_Str",Util.checkOtherName(player.getName())) == false) {
          Messages.sendMessage(Message.login_notregistered,player,null);
        }
 else         if (plugin.isAuthorized(player)) {
          Messages.sendMessage(Message.login_authorized,player,null);
        }
 else         if (split.length < 2) {
          Messages.sendMessage(Message.login_usage,player,null);
        }
 else         if (this.plugin.checkPassword(player.getName(),split[1])) {
          Processes.Login(player);
          Messages.sendMessage(Message.login_success,player,null);
        }
 else {
          if (Config.authdb_enabled) {
            Messages.sendMessage(Message.login_failure,player,null);
          }
 else {
            Messages.sendMessage(Message.login_offline,player,null);
          }
        }
        Util.logging.Debug(player.getName() + "String_Node_Str");
        event.setMessage(Config.commands_login + "String_Node_Str");
        event.setCancelled(true);
      }
 else {
        Messages.sendMessage(Message.protection_denied,player,null);
      }
    }
 else     if (split[0].equalsIgnoreCase(Config.commands_link) || split[0].equalsIgnoreCase(Config.aliases_link)) {
      if (Config.link_enabled) {
        if (ZPermissions.isAllowed(player,Permission.command_link)) {
          if (split.length == 3) {
            if (!player.getName().equals(split[1])) {
              if (Util.checkOtherName(player.getName()).equals(player.getName())) {
                EBean eBeanClass=EBean.checkPlayer(split[1],true);
                String linkedname=eBeanClass.getLinkedname();
                if (linkedname != null) {
                  Messages.sendMessage(Message.link_duplicate,player,null);
                }
 else                 if (this.plugin.checkPassword(split[1],split[2])) {
                  Processes.Link(player,split[1]);
                  Messages.sendMessage(Message.link_success,player,null);
                }
 else {
                  Messages.sendMessage(Message.link_failure,player,null);
                }
              }
 else {
                Messages.sendMessage(Message.link_exists,player,null);
              }
            }
 else {
              Messages.sendMessage(Message.link_invaliduser,player,null);
            }
          }
 else {
            Messages.sendMessage(Message.link_usage,player,null);
          }
          Util.logging.Debug(player.getName() + "String_Node_Str");
          event.setMessage(Config.commands_link + "String_Node_Str");
          event.setCancelled(true);
        }
 else {
          Messages.sendMessage(Message.protection_denied,player,null);
        }
      }
    }
 else     if (split[0].equalsIgnoreCase(Config.commands_unlink) || split[0].equalsIgnoreCase(Config.aliases_unlink)) {
      if (Config.unlink_enabled) {
        if (ZPermissions.isAllowed(player,Permission.command_unlink)) {
          if (split.length == 3) {
            if (Util.checkOtherName(player.getName()).equals(player.getDisplayName())) {
              EBean eBeanClass=EBean.checkPlayer(player,true);
              String linkedname=eBeanClass.getLinkedname();
              if (linkedname.equals(split[1])) {
                if (this.plugin.checkPassword(split[1],split[2])) {
                  Processes.Unlink(player,split[1]);
                  Messages.sendMessage(Message.unlink_success,player,null);
                }
 else {
                  Messages.sendMessage(Message.unlink_invalidpass,player,null);
                }
              }
 else {
                Messages.sendMessage(Message.unlink_invaliduser,player,null);
              }
            }
 else {
              Messages.sendMessage(Message.unlink_nonexist,player,null);
            }
          }
 else {
            Messages.sendMessage(Message.unlink_usage,player,null);
          }
          Util.logging.Debug(player.getName() + "String_Node_Str");
          event.setMessage(Config.commands_unlink + "String_Node_Str");
          event.setCancelled(true);
        }
 else {
          Messages.sendMessage(Message.protection_denied,player,null);
        }
      }
    }
 else     if (split[0].equalsIgnoreCase(Config.commands_register) || split[0].equalsIgnoreCase(Config.aliases_register)) {
      if (ZPermissions.isAllowed(player,Permission.command_register)) {
        Boolean email=true;
        if (Config.custom_enabled) {
          email=Config.custom_emailrequired;
        }
        if (Config.custom_emailfield == null || Config.custom_emailfield == "String_Node_Str") {
          email=false;
        }
        if (!Config.register_enabled) {
          Messages.sendMessage(Message.register_disabled,player,null);
        }
 else         if (this.plugin.isRegistered("String_Node_Str",player.getName()) || this.plugin.isRegistered("String_Node_Str",Util.checkOtherName(player.getName()))) {
          Messages.sendMessage(Message.register_exists,player,null);
        }
 else         if (split.length < 2) {
          Messages.sendMessage(Message.register_usage,player,null);
        }
 else         if (split.length < 3 && email) {
          Messages.sendMessage(Message.email_required,player,null);
        }
 else         if ((split.length >= 3 && email) && (!this.plugin.checkEmail(split[2]))) {
          Messages.sendMessage(Message.email_invalid,player,null);
        }
 else {
          try {
            if (split.length >= 3 || (!email && split.length >= 2)) {
              String themail=null;
              if (!email) {
                themail=null;
              }
 else {
                themail=split[2];
              }
              if (this.plugin.register(player,split[1],themail,Util.craftFirePlayer.getIP(player))) {
                if (Processes.Login(player)) {
                  Messages.sendMessage(Message.register_success,player,null);
                }
 else {
                  Messages.sendMessage(Message.register_failure,player,null);
                  Util.logging.Debug("String_Node_Str");
                }
              }
            }
          }
 catch (          IOException e) {
            Messages.sendMessage(Message.register_failure,player,null);
            Util.logging.StackTrace(e.getStackTrace(),Thread.currentThread().getStackTrace()[1].getMethodName(),Thread.currentThread().getStackTrace()[1].getLineNumber(),Thread.currentThread().getStackTrace()[1].getClassName(),Thread.currentThread().getStackTrace()[1].getFileName());
          }
catch (          SQLException e) {
            Messages.sendMessage(Message.register_failure,player,null);
            Util.logging.StackTrace(e.getStackTrace(),Thread.currentThread().getStackTrace()[1].getMethodName(),Thread.currentThread().getStackTrace()[1].getLineNumber(),Thread.currentThread().getStackTrace()[1].getClassName(),Thread.currentThread().getStackTrace()[1].getFileName());
          }
        }
        Util.logging.Debug(player.getName() + "String_Node_Str");
        event.setMessage(Config.commands_register + "String_Node_Str");
        event.setCancelled(true);
      }
 else {
        Messages.sendMessage(Message.protection_denied,player,null);
      }
    }
 else     if (!plugin.isAuthorized(player)) {
      if (!checkGuest(player,Config.guests_commands)) {
        event.setMessage("String_Node_Str");
        event.setCancelled(true);
      }
    }
  }
 else {
    Util.logging.Debug("String_Node_Str" + event.getMessage());
  }
  long stop=Util.timeMS();
  Util.logging.timeUsage(stop - start,"String_Node_Str");
}