QGuiApplication, platform plugins: don't modify AA_DontUseNativeMenuBar

The default should be false, meaning the application will prefer to
use a native menubar if the platform supports it.  The application
author can set it to true if he wants to always use a Qt-rendered
menubar instead; or, he can call QMenuBar::setNativeMenuBar().
Qt and its plugins should not override the author's wishes.
Instead, if the platform plugin cannot create a native menubar
for whatever reason, createPlatformMenuBar() will return null,
and QMenuBar will fall back to using a Qt menubar instead.
The application can check the result via QMenuBar::isNativeMenuBar().

QMdiArea when maximized inside a QMainWindow with an empty title
does not replace the main window's title if we are using native menus.
This behavior turned out to be the same on Unity as it is on macOS,
so the autotest needed adjustment to expect that behavior whenever
the menubar is native, not only on certain platforms.

tst_QMenuBar::allowActiveAndDisabled() tests a standalone QMenuBar.
In f92f78094 it was disabled on macOS, but on Ubuntu it passes as
long as we force it to be a non-native menubar, so it should pass
that way on macOS too.  Removed unused variable RESET to fix warning.

Task-number: QTBUG-54793
Change-Id: I716e40da709f96331cbbf25213bd7bc153e4dbe2
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

1 files changed, 0 insertions, 2 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index f02dad675e..e481cede17 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -300,8 +300,6 @@ QCocoaIntegration::QCocoaIntegration(const QStringList &paramList)
     initResources();
     QMacAutoReleasePool pool;
 
-    qApp->setAttribute(Qt::AA_DontUseNativeMenuBar, false);
-
     NSApplication *cocoaApplication = [QNSApplication sharedApplication];
     qt_redirectNSApplicationSendEvent();