bug#6116: Emacs 23 is sluggish with Consolas font

[Vegard Øye]

I use 23.1.1 (i386-mingw-nt5.1.2600) of 2009-07-30 on Windows XP.
My font of choice is Consolas, which was originally released with
Windows Vista, but can be downloaded from the URL below.

Since I moved from 22.3 to 23.1, Emacs has become noticeably slower,
particularly when scrolling. The problems vanish when I select any
other font than Consolas.

WITHOUT CONSOLAS: My .emacs consists of the following two lines.

        (setq scroll-step 1)
        ;; (set-frame-font "Consolas-11")

When I start up Emacs, the font is Courier New. I open the tutorial
with C-h t and hold down C-n until the cursor reaches the bottom of
the screen. When it does, the text scrolls smoothly.

WITH CONSOLAS: I uncomment the second line and start Emacs anew.

        (setq scroll-step 1)
        (set-frame-font "Consolas-11")

Now C-n doesn't scroll at all. Instead, the cursor is repeatedly
recentered each time it reaches the bottom of the screen.

If display-intensive packages like hl-line-mode and show-paren-mode
are loaded as well, Emacs slows to a crawl.

WITH OTHER FONTS: No problems with Lucida Console!

        (setq scroll-step 1)
        (set-frame-font "Lucida Console-11")

This is just as responsive as the default of Courier New.

DOWNLOAD: Consolas is included with Windows Vista and Windows 7.
Otherwise, an .exe installer is available from the address below.
If this is unpractical, mail me and we'll figure out something.

http://www.microsoft.com/downloads/details.aspx?familyid=22e69ae4-7e40-4807-8a86-b3d36fab68d3

Vegard                                    
_________________________________________________________________
Windows 7: Du får hjelp til gjøre mer. Utforsk Windows 7.
http://windows.microsoft.com/windows-7