lynx-dev ~^G (was Re: Fix for keybinding and statusline problem)

[Klaus Weide]

On Sun, 14 Feb 1999, Doug Kaufman wrote:
>
> On Sun, 14 Feb 1999, I wrote:
> 
> > lynxactions. Neither SLANG port displays characters > 0x80 normally
> > in textedit mode. They appear as "~" plus a character representing
> > (ch - 128), so decimal 129 appears as ~^A and 135 appears as ~^G. This
> > only applies to display.

That is controlled by SLsmg_Display_Eight_Bit, which lynx sets according
to the lowest_eightbit for the DIsplay Character Set.  Slang does that
replacement representation for 8-bit characters below SLsmg_Display_Eight_Bit.
It's useful since it can protect against accidental receiving of 8-bit
control characters to a real terminal or emulator.

Normally characters that are subject to this are filtered out or translated
by lynx at an earlier stage.

If your Display Character Set is ISO-8859-1 you're not supposed to be able
to enter such characters since they are control characters.  So it's not
surprising that Lynx shows them in an unusual way, if against expectations
(or because you're lying to Lynx about the Display Character Set) you are
able to enter them.

> I checked this some more. The SLang port handles the characters
> correctly if the Display Character Set, Assumed Character Set, and the
> actual terminal display all match. The ~^G display occurs when the
> Display Character Set is set to ISO 8859-1 for an Assumed Character
> Set of ISO 8859-1 (the character is not in the Character Set).
> When both are set to cp437, the character displays correctly. This
> translation doesn't occur with the PDCurses port in textedit mode.
> The appearance in a rendering of a text file containing these cp437
> characters also varies between the ports. The Slang port actually
> seems more accurate.

How does the appearance differ?  Either the right characters are shown
or not, is one of the versions showing the wrong characters when you
have the correct Display Character Set specified?  That would be a bug
either in Lynx or in PDcurses.

   Klaus