xsrc/60398: Line drawing in xterm does not work as expected

["he%NetBSD.org@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60398
>Category:       xsrc
>Synopsis:       Line drawing in xterm does not work as expected
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    xsrc-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 02 21:50:00 +0000 2026
>Originator:     Havard Eidnes
>Release:        NetBSD 11.99.4
>Organization:
	I try...
>Environment:
System: NetBSD st.urc.uninett.no 11.99.4 NetBSD 11.99.4 (GENERIC) #0: Sat Dec  6 13:05:05 UTC 2025  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
	The "dua" program from the "dua-cli" package and Jonathan
	Perkins' new "bob" package bulk manager from pkgtools/bob 
	both try to draw using utf-8 line drawing characters in the
	terminal.

	In an xterm from NetBSD 10.1, I need to bring up the font
	menu with "ctrl+right-click" and select "UTF-8 Encoding",
	and then a "dua i" invocation produces a nicely framed
	drawing with utf-8 line drawing characters.

	The same can be done on NetBSD 9.3.

	However, if I do the same with xterm from either 11.0_RC5
	or 11.99.4, I do not get the same result.  The line drawing
	characters are all (horizontal or vertical) replaced with
	a character 'a' with a '^' on top of it.

	This is reproducible with

	printf "\xe2\x94\x82\n"

	which produces a vertical line drawing character on 9.3
	or 10.1, but produces the aforementioned combined 'a'/'^'
	on the xterm from the newer OS variants.

	Similarly

	printf "\xe2\x94\x80\n"

	produces a horizontal line drawing character on the older OSes'
	xterms, but the aforementioned 'a'/'^' combination character
	in the xterm from the newer OS variants.

	Locale setting does not appear to make any difference in
	the result.

	Copying the xterm from a 10.1 system and running it on an
	11.99.4 system and running "due i" inside it produces nice
	line drawing characters.

	So ... this appears to be an xterm issue.  Either it now
	insists on more settings (unknown to me) to allow UTF-8
	coded data, or it has a new bug.

>How-To-Repeat:
	See above.
>Fix:
	Wouldn't that be nice!