bug#46990: 28.0.50; popup menu not navigable via arrow keys on lucid build

[Colin Baxter <m43cap@yandex.com>]

>>>>> Basil L Contovounesios <contovob@tcd.ie> writes:

    > Colin Baxter <m43cap@yandex.com> writes:
    >> In GNU Emacs 28.0.50 (build 1, i686-pc-linux-gnu, X toolkit,
    >> cairo version 1.14.8, Xaw3d scroll bars) of 2021-03-07 built on
    >> bluestar Repository revision:
    >> 8558ecd65fc1c87345353f6352299df04280e729 Repository branch:
    >> master System Description: Debian GNU/Linux 9 (stretch)
    >> 
    >> Configured using: 'configure --with-x-toolkit=lucid'

    > Just curious: how come this doesn't list your 'Windowing system
    > distributor' (which in my case is X.Org 11), when your features
    > below include X11?  Do you need to configure '--with-x' or
    > something?
    
I'm tried this but get the same result.

    >> Configured features: ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS
    >> GPM GSETTINGS HARFBUZZ JPEG LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD
    >> LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY PDUMPER PNG RSVG SOUND
    >> THREADS TIFF TOOLKIT_SCROLL_BARS X11 XAW3D XDBE XIM XPM LUCID
    >> ZLIB
    >> 
    >> Important settings: value of $LANG: en_GB.utf8
    >> locale-coding-system: utf-8

    > Apart from that, the only possibly significant differences I see
    > from my configuration of Emacs 28[1] are: I'm on x86_64, with a
    > more recent version of Debian and Cairo, and 'value of
    > $XMODIFIERS: @im=ibus'.  So I'm not sure what's going on.

It does look as if something changed between pretests 1, 2. Pretest 2 has
the same issue as emacs-28 - I'm not certain, but I think pretest 1
didn't. Unfortunately, I deleted pretest 1!

Perhaps the fact that I'm on 32 bits is significant. I don't have any
more time today to look at this, but I will later in the week.

Best wishes,