Qt 5.9 introduces many new features and improvements as well as bugfixes
over the 5.8.x series. For more details, refer to the online documentation
included in this distribution. The documentation is also available online:

http://doc.qt.io/qt-5/index.html

With the exception noted below, the Qt version 5.9 series is binary compatible
with the 5.8.x series. Applications compiled for 5.8 will continue to run with 5.9.

Some of the changes listed in this file include issue tracking numbers
corresponding to tasks in the Qt Bug Tracker:

https://bugreports.qt.io/

Each of these identifiers can be entered in the bug tracker to obtain more
information about a particular change.

Important Changes
-----------------

 * Binary compatibility breakage in QtWaylandCompositor.

   The class QWaylandQuickOutput now also inherits from QQmlParserStatus. This class
   is primarily useful from QML, and there is little reason for it to used in
   user C++ code. Any compositor using or instantiating the QtWaylandCompositor class
   from C++ will have to be recompiled against Qt 5.9. Failure to do so may lead to crashes,
   buffer overruns, or undefined behavior.

Client
------

 - Added xdg_shell_v6 support for Qt clients.

 - Clients now default to using xdg_shell_v6 if available, else wl_shell.

 - Deprecated the QT_WAYLAND_USE_XDG_SHELL environment variable in favor of
   QT_WAYLAND_SHELL_INTEGRATION, which can be set to one of [ivi-shell, wl-shell,
   xdg-shell-v5, xdg-shell-v6].

 - Fixed crash when the receiver of a paste closes the pipe.


Compositor
----------

 - QWaylandQuickOutput: Automatically set the compositor if output is a child of
   the compositor.

 - QWaylandXdgSurfaceV5 now sets the windowType property and behaves like
   other shell surface implementations.

 - QWaylandXdgPopupV5 position property now has change notification.

 - [QTBUG-55303] Added support for running compositors with custom device pixel ratio.

 - [QTBUG-58299] Fixed wayland-egl compositing using NVIDIA graphics.