openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

console ASCII glyph 1:1 mapping 

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@wupperonline.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Egmont Koblinger <egmont@uhulinux.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ingo Brueckl 2008-12-10 23:35:00 +01:00 committed by Linus Torvalds
parent f75bc06e5d
commit 1c55f18717
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/char/vt.c
View File

@ -2274,7 +2274,7 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
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