bug#30543: 25.2; Emacs overuses CPU on session startup in separate virtual desktop

[Quentin Jankosky]

To have this bug occur, you must have emacs saved in a desktop session,
and have more than one virtual desktop. This seems to happen in XFCE.

1) Start emacs (gtk mode) in a virtual desktop.
2) Select a different virtual desktop.
3) Logout of the DE, effectively saving the current session and saving
the previously selected desktop.
4) Log back in
ISSUE) Emacs will run on the desktop it was saved on in the session, but
will use massive amounts of CPU until the desktop is selected.

Once emacs is focused on, it properly loads and stops using large
amounts of CPU.

This is not a major bug, but it is a nuisance.



In GNU Emacs 25.2.2 (x86_64-pc-linux-gnu, GTK+ Version 3.22.20)
of 2017-09-11, modified by Debian built on trouble
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description: Debian GNU/Linux testing (buster)

Configured using:
'configure --build x86_64-linux-gnu --prefix=/usr
--sharedstatedir=/var/lib --libexecdir=/usr/lib
--localstatedir=/var/lib --infodir=/usr/share/info
--mandir=/usr/share/man --with-pop=yes
--enable-locallisppath=/etc/emacs25:/etc/emacs:/usr/local/share/emacs/25.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/25.2/site-lisp:/usr/share/emacs/site-lisp 

--with-sound=alsa --without-gconf --build x86_64-linux-gnu
--prefix=/usr --sharedstatedir=/var/lib --libexecdir=/usr/lib
--localstatedir=/var/lib --infodir=/usr/share/info
--mandir=/usr/share/man --with-pop=yes
--enable-locallisppath=/etc/emacs25:/etc/emacs:/usr/local/share/emacs/25.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/25.2/site-lisp:/usr/share/emacs/site-lisp 

--with-sound=alsa --without-gconf --with-x=yes --with-x-toolkit=gtk3
--with-toolkit-scroll-bars 'CFLAGS=-g -O2
-fdebug-prefix-map=/build/emacs25-XrMyQe/emacs25-25.2+1=. 
-fstack-protector-strong
-Wformat -Werror=format-security -Wall' 'CPPFLAGS=-Wdate-time
-D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'

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

Important settings:
value of $LANG: en_US.utf8
locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
tooltip-mode: t
global-eldoc-mode: t
electric-indent-mode: t
mouse-wheel-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
column-number-mode: t
line-number-mode: t
transient-mark-mode: t

Recent messages:
Loading debian-ispell...done
Loading /var/cache/dictionaries-common/emacsen-ispell-dicts.el 
(source)...done
Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)...done
Loading /etc/emacs/site-start.d/50gnugo.el (source)...
Package gnugo removed but not purged. Skipping setup.
Loading /etc/emacs/site-start.d/50gnugo.el (source)...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Loading 
/home/quentin/.emacs.d/session.22aca77c6-5626-47a1-b664-797068b402a4...done
Restored session data
Making completion list...

Load-path shadows:
/usr/share/emacs25/site-lisp/cmake-data/cmake-mode hides 
/usr/share/emacs/site-lisp/cmake-mode
/usr/share/emacs/25.2/site-lisp/debian-startup hides 
/usr/share/emacs/site-lisp/debian-startup

Features:
(shadow sort mail-extr emacsbug message dired format-spec rfc822 mml
mml-sec password-cache epg gnus-util 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
misterioso-theme edmacro kmacro finder-inf package epg-config seq
byte-opt gv bytecomp byte-compile cl-extra help-mode easymenu cconv
cl-loaddefs pcase cl-lib time-date mule-util tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win
term/common-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 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 charscript case-table epa-hook jka-cmpr-hook help
simple abbrev 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 174714 8307)
(symbols 48 25320 0)
(miscs 40 489 132)
(strings 32 40760 7631)
(string-bytes 1 1103670)
(vectors 16 18748)
(vector-slots 8 542552 5681)
(floats 8 200 111)
(intervals 56 297 0)
(buffers 976 18))