kern/59734: xterm-style 256 colour support for wscons

[nia%pkgsrc.org@localhost]

>Number:         59734
>Category:       kern
>Synopsis:       xterm-style 256 colour support for wscons
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Tue Oct 28 13:20:00 +0000 2025
>Originator:     nia
>Release:        -current, -11, any
>Organization:
The NetBSD 256colouration
>Environment:
>Description:
Increasingly command-line applications are built to take advantage of
colours beyond the standard 8 provided by the ANSI escape codes.

These extensions are not generally standardized, but xterm serves
as a de-facto standard.

Since wscons already has full support of 8/16/24/32-bit displays (and
can take advantage of them for antialiased fonts), this is mostly a
change to wscons' vt100 emulation.

Informing applications about this support via termcap should be
investigated by someone(tm) separately.

Colour averse hackers can disable colour in applications by setting
TERM=vt100.
>How-To-Repeat:
A test script is provided in the mailing list thread linked.
>Fix:
A patch is available here:

https://mail-index.netbsd.org/tech-kern/2025/10/28/msg030747.html