Re: [PATCH] console ASCII glyph 1:1 mapping

From: Linus Torvalds
Date: Thu Dec 11 2008 - 11:25:26 EST



Hmm. I bounced both your patches to Peter, since they look valid but I
want somebody who knows this code better to ack them.

Peter - is there somebody else who should double-check these things, or
can you ack them?

Linus

On Wed, 10 Dec 2008, Ingo Brueckl wrote:
>
> For the console, there is a 1:1 mapping of glyphs which cannot be found
> in the current font. This seems to be meant as a kind of 'emergency
> fallback' for fonts without unicode mapping which otherwise would
> display nothing readable on the screen.
>
> At the moment it affects all chars for which no substitution character
> is defined. In particular this means that for all chars (>= 128) where
> there is no iso88591-1/unicode character (e.g. control character area)
> you'll get the very strange 1:1 mapping of the (cp437) graphics card
> glyphs.
>
> I'm pretty sure that the 1:1 mapping should only affect strict ASCII
> code characters, i.e. chars < 128.
>
> The patch limits the mapping as it probably was meant anyway.
>
> Signed-off-by: Ingo Brueckl <ib@xxxxxxxxxxxxxxx>
>
> --- linux-2.6.27.8.orig/drivers/char/vt.c 2008-12-05 21:03:02.000000000 +0100
> +++ linux-2.6.27.8/drivers/char/vt.c 2008-12-10 20:51:30.000000000 +0100
> @@ -2287,7 +2287,7 @@ rescan_last_byte:
> continue; /* nothing to display */
> }
> /* Glyph not found */
> - if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
> + if ((!(vc->vc_utf && !vc->vc_disp_ctrl) && c < 128) && !(c & ~charmask)) {
> /* In legacy mode use the glyph we get by a 1:1 mapping.
> This would make absolutely no sense with Unicode in mind,
> but do this for ASCII characters since a font may lack
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/