CUPS Print Self Test Page does not work for non-Postscript printers

[George Liu]

I'm using Ubuntu 10.10 with CUPS 1.4.4.

I setup a printer queue for a PCL-XL printer, using socket 9100 protocol.
>From CUPS web interface, I picked "Maintenance-> Print Self Test Page".

The test page printed, however, it printed the following information:

-----------------------------------------------------------------
%!
  userdict dup(\004) cvn{}put (\004\004)cvn{}put
                            % You are using the wrong driver
-----------------------------------------------------------------

It seems that the command did not go through filter chain and landed in printer directly. What will confuse the user is the sentence "You are using the wrong driver".

On a Postscript printer, it worked fine, and printed out printer model name along with PSVersion.

Can we change the print self-test content to be something neutral?