bug#27210: 25.2; Recovering loaddefs.el with desktop-mode hangs when linum is on

[Pierre Neidhardt <ambrevar@gmail.com>]

With the following init file:

	(desktop-save-mode 1)
	(global-linum-mode)

I visit "/usr/share/emacs/25.2/lisp/loaddefs.el" and everything is fine.
I save the desktop session with `desktop-save-in-desktop-dir' and kill
Emacs.

On next start, this displays in the terminal

	Warning: due to a long standing Gtk+ bug
	http://bugzilla.gnome.org/show_bug.cgi?id=85715
	Emacs might crash when run in daemon mode and the X11 connection is unexpectedly lost.
	Using an Emacs configured with --with-x-toolkit=lucid does not have this problem.
	Note: file is write protected

and Emacs hangs for minutes at least, possibly forever, becoming a CPU hog. I
then have to kill Emacs.

The corresponding buffer entry in .emacs.desktop is the following:

	;; Buffer section -- buffers listed in same order as in buffer list:
	(desktop-create-buffer 208
	  "/usr/share/emacs/25.2/lisp/loaddefs.el"
	  "loaddefs.el"
	  'emacs-lisp-mode
	  '(linum-mode)
	  1
	  '(nil nil)
	  t
	  nil
	  '((buffer-file-coding-system . utf-8-unix))
	  '((mark-ring nil)))

If I remove the entry or if I disable linum-mode by commenting the corresponding
line in the init file, Emacs can start properly.





In GNU Emacs 25.2.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.22.10)
 of 2017-04-22 built on juergen
Windowing system distributor 'The X.Org Foundation', version 11.0.11903000
System Description:	Arch Linux

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-modules
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe
 -fstack-protector-strong' CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro'

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

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

Major mode: Lisp Interaction

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