bug#23507: 24.3; Mac OS X proxy icon disappears when frame-title-format is set in .emacs

[Christopher Crawford]

Using the following one-line .emacs file:

(setq frame-title-format '("%b @ " system-name))

removes the proxy icon from the mode line when opening ~/.emacs, for example.
After emacs is running, if I evaluate the two lines:

(setq frame-title-format t)
(setq frame-title-format '("%b @ " system-name))

the proxy icon reappears with the rest of the title format specified.
This bug appeared some time after version 'GNU Emacs 22.3.1 
(i386-apple-darwin9.8.0, Carbon Version 1.6.0) of 2010-01-09 on 
gs674-seijiz.local'




In GNU Emacs 24.3.1 (x86_64-apple-darwin, NS apple-appkit-1038.36)
of 2013-03-13 on bob.porkrind.org
Windowing system distributor `Apple', version 10.3.1265
Configured using:
`configure '--host=x86_64-apple-darwin' '--build=i686-apple-darwin'
'--with-ns' 'build_alias=i686-apple-darwin'
'host_alias=x86_64-apple-darwin' 'CC=gcc -mmacosx-version-min=10.7
-isystem
/Users/david/Xcode-10.7_4.5.2/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk/usr/include/
-F/Users/david/Xcode-10.7_4.5.2/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk/System/Library/Frameworks''

Important settings:
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  tooltip-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

Recent input:
<help-echo> C-x C-f . <backspace> <backspace> ~ / . 
e m <tab> <return> C-n C-n C-e C-x C-e C-p C-p C-x 
C-e C-n C-n C-e C-x C-e C-a C-p C-k C-k <help-echo> 
s-x r e C-/ M-x r e p r o t SPC <backspace> <backspace> 
<backspace> o r t SPC e m a SPC b u SPC <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Loading vc-cvs...done
("%b @ " system-name)
t
("%b @ " system-name)
kill-region: The mark is not set now, so there is no region
Undo!

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message 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 mail-prsvr mail-utils parse-time vc-cvs time-date tooltip
ediff-hook vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset
image regexp-opt fringe tabulated-list newcomment lisp-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 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 ns multi-tty emacs)