Cursor movement in Korean text is slow with xfonts-baekmuk

[Jae-hyeon Park]

Binary package hint: emacs23

Source package: emacs23
Ubuntu release: 9.10 amd64
Package version: 23.1+1-4ubuntu3

I use the bitmap font xfonts-baekmuk to display Korean characters in emacs. When there are many Korean characters in a buffer, moving the cursor among the Korean characters takes a long time (like a few seconds on my laptop which is a fairly new hardware).

How to reproduce:

1) Start emacs with

    $ emacs23 -Q -xrm 'Emacs.FontBackend: x' &

2) In the scratch buffer, evaluate the following code

    (create-fontset-from-fontset-spec
     "-misc-fixed-medium-r-normal--15-140-75-75-c-90-fontset-baekmuk,
      ascii:-misc-fixed-medium-r-normal--15-140-75-75-c-90-iso8859-1")
    (set-fontset-font "fontset-baekmuk" 'korean-ksc5601
     "-baekmuk-gulim-medium-r-normal--18-180-75-75-m-180-ksc5601.1987-0")
    (set-frame-font "fontset-baekmuk")

3) Open the attached file in the same frame

4) Try to move the cursor downwards by pressing C-n several times

I don't know whether this is a problem of emacs23 or of xfonts-baekmuk.