When allocating a new VC with vgacon_init(), the font is
shared across all the VGA consoles. However, the font
mask was always set to the default value of zero in visual_init(),
even if we were using 512 character fonts at the time.
Moreover, code in vgacon.c:vga_do_font_op() didn't reset
the mask if the console driver thinks it's already in 512 character
mode. This means that to *fix* it, you'd actually have to take
the console out of 512 character mode and then set it back.
The attached sets vc_hi_font_mask in vgacon_init() for
any new consoles opened if the vgacon driver is already
in 512 character mode, solving this.
This bug goes back to 2.4.18 at least, probably earlier.
Bill