maintainer-feedback requested: [Bug 270695] www/firefox: fails to render parts of some Web pages as of firefox-111

From: <>
Date: Sat, 08 Apr 2023 00:49:31 UTC
Bugzilla Automation <> has asked freebsd-gecko (Nobody)
<> for maintainer-feedback:
Bug 270695: www/firefox: fails to render parts of some Web pages as of

--- Description ---
This is running:
FreeBSD 12.4-STABLE FreeBSD 12.4-STABLE #1377
stable/12-n236087-95d0723eb308: Thu Mar 30 10:32:05 UTC 2023  amd64
1204500 1204500

with ports updated from a ports tree at main-n614944-8641bb99a224.
In particular, www/firefox is:

g1-97(12.4-S)[7] pkg info www/firefox
Name	       : firefox
Version        : 112.0_1,2
Installed on   : Fri Apr  7 04:29:07 2023 PDT
Origin	       : www/firefox
Architecture   : FreeBSD:12:amd64
Prefix	       : /usr/local
Categories     : www wayland
Licenses       :
Maintainer     :
WWW	       :
Comment        : Web browser based on the browser portion of Mozilla
Options        :
	ALSA	       : on
	CANBERRA       : off
	DBUS	       : off
	DEBUG	       : off
	FFMPEG	       : on
	JACK	       : on
	LIBPROXY       : off
	LTO	       : off
	PROFILE        : off
	PULSEAUDIO     : on
	SNDIO	       : off
	TEST	       : off

Base FreeBSD and installed ports are updated daily (building each locally --
except for www/chromium).  (There have been no updates to FreeBSD stable/12
since 30 March -- as of this writing.]

An example Web page that exhibits the failure is --
firefox-110 and prior rendered the entire page, as does www/chromium
(chromium-111.0.5563.147); firefox-111 shows blank for the upper-left part of
the page; shows the main cartoon and the tooltip; shows buttons above and below
the cartoon (but not the names on the buttons).  When I slide the mouse around
in that upper-left corner, the cursor changes to indicate a link, and a
horizontal line shows up (where a graphic is expected to be).  Also, the
buttons (above & below the cartoon) are solid grey, but switch to white on
mouseover -- and the cursor switches to indicate a link.

Since it proved to be an issue for a different problem I was having with
firefox (drop-down menus would disappear as soon as I moved the mouse to try to
select an entry), I should point out that I am using a window manager that is a
derivative of tvtwm (and that has not been updated in years).  [For this issue,
the circumvention that I found was to define an environment variable,
XDG_SESSION_DESKTOP, to have the value "twm" in my X11 startup -- in my case,
in ~/.xsession.]

I see no errors emitted to ~/xsession-errors when I refresh the xkcd page.  (I
do see some errors for other pages -- e.g., whines about JavaScript errors.) 
Nor do I see anything at all interesting by examining the Web browser console
(F12; select "Console" & refresh the page.