bug#27667: 26.0.50; Dynamic menu is not updated (gtk3 + hidpi scaling)

[jsynacek]

Reproducible on the current master (commit 
d014a5e15c1110af77e7a96f06ccd0f0cafb099f).

Steps to reproduce:
0) Use gnome-tweak-tool to set scaling to 2x ("Windows" -> "Window
scaling" -> set to 2)
   This step is very important, it makes this bug reproducible.
1) $ emacs -Q first.py
2) C-x C-f ~/second.html
3) Click the "SGML" menu
4) Observe a tiny rectangular area with nothing in it

If I start emacs as "emacs -Q second.hmtl" the menu is fine.

Originally reported at: https://bugzilla.redhat.com/show_bug.cgi?id=1384185


In GNU Emacs 26.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.16)
 of 2017-07-12 built on localhost-live
Repository revision: d014a5e15c1110af77e7a96f06ccd0f0cafb099f
Windowing system distributor 'Fedora Project', version 11.0.11903000
Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Can’t guess python-indent-offset, using defaults: 4
Quit
Making completion list...
delete-backward-char: Text is read-only [4 times]
Making completion list... [2 times]
funcall-interactively: End of buffer [3 times]

Configured using:
 'configure --with-dbus --with-gif --with-jpeg --with-png --with-rsvg
 --with-tiff --with-xft --with-xpm --with-x-toolkit=gtk3 --with-gpm=no'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GCONF GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Python

Minor modes in effect:
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message subr-x puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg epg-config gnus-util rmail
rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils python easymenu tramp-sh tramp
tramp-compat tramp-loaddefs trampver ucs-normalize shell pcomplete
parse-time format-spec advice auth-source cl-seq eieio eieio-core
cl-macs eieio-loaddefs password-cache json map seq byte-opt gv bytecomp
byte-compile cconv comint ring cl-loaddefs cl-lib ansi-color time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar
dnd fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors frame cl-generic cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray minibuffer
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote dbusbind inotify
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 225308 11470)
 (symbols 48 22426 1)
 (miscs 40 49 151)
 (strings 32 37030 1286)
 (string-bytes 1 1098813)
 (vectors 16 39761)
 (vector-slots 8 761484 10766)
 (floats 8 67 113)
 (intervals 56 226 0)
 (buffers 976 13))