bug#18722: 25.0.50; UI partly unresponsive after re-focus of Emacs' window.

[Titus von der Malsburg]

Actions that trigger the bug:

1. Start emacs -Q.
2. Unfocus the application window, e.g., by clicking on another
application.
3. Re-focus Emacs.
4. Write something.

Result: The typed text does not appear.  When I click on a menu-item,
the typed text appears and the UI is responsive again.

I'm using the FVWM2 window manager under Ubuntu 14.04 and the latest
Emacs from git.  The problem first appeared when I recompiled Emacs two
weeks ago.  However, I can't pin down which commit introduced it because
I hadn't updated Emacs for several weeks before. 



In GNU Emacs 25.0.50.3 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.8)
 of 2014-10-14 on montana
Windowing system distributor `The X.Org Foundation', version 11.0.11501000
System Description:     Ubuntu 14.04.1 LTS

Configured using:
 `configure --prefix=/home/malsburg/usr/ --with-x-toolkit=yes
 --with-sound=no --without-gpm --without-dbus --without-gconf
 --without-gsettings --without-selinux --with-file-notification=yes
 --with-x PKG_CONFIG_PATH=/usr/local/X11R6.8/lib/pkgconfig'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK NOTIFY GNUTLS LIBXML2 FREETYPE
XFT ZLIB

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

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-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

Recent input:
M-x r e p o r t <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message dired format-spec
rfc822 mml easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util help-fns mail-prsvr mail-utils time-date tooltip
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
elisp-mode lisp-mode prog-mode register page menu-bar rfn-eshadow timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai
tai-viet lao korean japanese hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help
simple abbrev minibuffer 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 make-network-process
gfilenotify dynamic-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty emacs)

Memory information:
((conses 16 76554 5486)
 (symbols 48 18069 0)
 (miscs 40 46 113)
 (strings 32 11447 4270)
 (string-bytes 1 302141)
 (vectors 16 10017)
 (vector-slots 8 392276 11577)
 (floats 8 70 167)
 (intervals 56 185 0)
 (buffers 976 11)
 (heap 1024 36984 901))