bug#25542: 25.1; Restoring the frame from fullscreen to maximized

[Dani Moncayo]

Recipe from "emacs -Q"

1. Maximize the frame using the mouse -- for example, on MS-Windows,
either click on the "maximize" button or double click on the title
bar.

2. Switch to fullscreen by pressing F11.

3. Press F11 again.


Expected behavior: The frame goes to its previous state (i.e. maximized).

Observed behavior: The frame is not maximized (it is smaller that a
maximized one, both in height and width).


I'm using the Emacs distributed with cygwin, which uses the native
MS-Windows GUI (package "emacs-w32"):

In GNU Emacs 25.1.1 (x86_64-unknown-cygwin)
 of 2016-09-17 built on desktop-new
Windowing system distributor 'Microsoft Corp.', version 10.0.10586
Configured using:
 'configure
 --srcdir=/home/kbrown/src/cygemacs/emacs-25.1-1.x86_64/src/emacs-25.1
 --prefix=/usr --exec-prefix=/usr --localstatedir=/var --sysconfdir=/etc
 --docdir=/usr/share/doc/emacs --htmldir=/usr/share/doc/emacs/html -C
 --with-w32 'CFLAGS=-ggdb -O2 -pipe -Wimplicit-function-declaration
 
-fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-25.1-1.x86_64/build=/usr/src/debug/emacs-25.1-1
 
-fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-25.1-1.x86_64/src/emacs-25.1=/usr/src/debug/emacs-25.1-1'
 CPPFLAGS= LDFLAGS='

Configured features:
XPM JPEG TIFF GIF PNG IMAGEMAGICK SOUND DBUS NOTIFY ACL GNUTLS LIBXML2
ZLIB TOOLKIT_SCROLL_BARS

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

-- 
Dani Moncayo