[XP Script] Universal Message System Cancel Choices Fix

The Script
Code:
#==============================================================================

# ** Universal Message System:  Cancel Choices Fix

#------------------------------------------------------------------------------

#    by DerVVulfman

#    version 1.1

#    05-22-2012

#    RGSS / RPGMaker XP

#==============================================================================

# 

#  INTRODUCTION:

#

#  After noticing that version 1.8.0 of ccoa's UMS contained a bug whereby the

#  'Show Choices' window had difficulties with cancelled options, this fix was

#  made. The bug was where the default window of 1-4 choices was set to branch

#  to a 5th  'cancelled'  option, that option would exit out altogether.  This

#  fix returns that capability.

#

#  Show Choices with more than 4 visible options didn't have the problem and 

#  isn't touched.

#

#------------------------------------------------------------------------------

#

#  INSTALLATION:

#

#  Paste it directly below the UMS, and the fix is done.

#

#==============================================================================

#==============================================================================

# ** Game_Temp

#------------------------------------------------------------------------------

#  This class handles temporary data that is not included with save data.

#  Refer to "$game_temp" for the instance of this class.

#==============================================================================

class Game_Temp

  #--------------------------------------------------------------------------

  # * Public Instance Variables

  #--------------------------------------------------------------------------

  attr_accessor :detected_ums_cancel      # flag for canceled choices in UMS

end

#==============================================================================

# ** Window_Message

#------------------------------------------------------------------------------

#  This message window is used to display text.

#==============================================================================

class Window_Message < Window_Selectable

  #--------------------------------------------------------------------------

  # * Object Initialization

  #--------------------------------------------------------------------------

  alias ums_fix_initialize initialize

  def initialize

    # Set the 'detected cancel' flag to nil

    $game_temp.detected_ums_cancel = nil

    # Perform the original call

    ums_fix_initialize

  end

  #--------------------------------------------------------------------------

  # * Frame Update

  #--------------------------------------------------------------------------  

  alias ums_fix_update update

  def update

    # if the message window is showing

    if @contents_showing

      # Cancel

      if Input.trigger?(Input::B)

        if $game_temp.choice_max > 0 and $game_temp.choice_cancel_type > 0

          # Turn the 'detected cancel' flag on if set to less than 2 windows

          $game_temp.detected_ums_cancel = true if $game_temp.num_choices <= 1

        end

      end

    end

    # Perform the original call

    ums_fix_update

  end

end

#==============================================================================

# ** Interpreter

#------------------------------------------------------------------------------

#  This interpreter runs event commands. This class is used within the

#  Game_System class and the Game_Event class.

#==============================================================================

class Interpreter

  #--------------------------------------------------------------------------

  # * When Cancel

  #--------------------------------------------------------------------------

  def command_403

    # If choices are cancelled

    if @cancel_flag

      # Delete branch data

      @branch.delete(@list[@index].indent)

      # Continue

      return true

    end

    # If it doen't meet the condition and 'detected cancel' not found: command_skip

    return command_skip unless $game_temp.detected_ums_cancel == true

    # Reset the 'detected cancel' flag

    $game_temp.detected_ums_cancel = nil

  end

end