4 files changed, 36 insertions, 7 deletions

diff --git a/src/plugins/platforms/winrt/qwinrteglcontext.cpp b/src/plugins/platforms/winrt/qwinrteglcontext.cpp
index 1008e1c5e8..8ca669141e 100644
--- a/src/plugins/platforms/winrt/qwinrteglcontext.cpp
+++ b/src/plugins/platforms/winrt/qwinrteglcontext.cpp
@@ -46,6 +46,7 @@
 #define EGL_EGLEXT_PROTOTYPES
 #include <EGL/eglext.h>
 
+#include <QOffscreenSurface>
 #include <QOpenGLContext>
 #include <QtPlatformSupport/private/qeglconvenience_p.h>
 
@@ -54,9 +55,6 @@ QT_BEGIN_NAMESPACE
 struct WinRTEGLDisplay
 {
     WinRTEGLDisplay() {
-        eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-        if (Q_UNLIKELY(eglDisplay == EGL_NO_DISPLAY))
-            qCritical("Failed to initialize EGL display: 0x%x", eglGetError());
     }
     ~WinRTEGLDisplay() {
         eglTerminate(eglDisplay);
@@ -117,9 +115,17 @@ void QWinRTEGLContext::initialize()
     if (Q_UNLIKELY(g->eglDisplay == EGL_NO_DISPLAY))
         qCritical("Failed to initialize EGL display: 0x%x", eglGetError());
 
-    if (Q_UNLIKELY(!eglInitialize(g->eglDisplay, nullptr, nullptr)))
-        qCritical("Failed to initialize EGL: 0x%x", eglGetError());
-
+    // eglInitialize checks for EGL_PLATFORM_ANGLE_ENABLE_AUTOMATIC_TRIM_ANGLE
+    // which adds a suspending handler. This needs to be added from the Xaml
+    // thread itself, otherwise it will not be invoked. add_Suspending does
+    // not return an error unfortunately, so it silently fails and causes
+    // applications to not quit when the system wants to terminate the app
+    // after suspend.
+    hr = QEventDispatcherWinRT::runOnXamlThread([]() {
+        if (!eglInitialize(g->eglDisplay, nullptr, nullptr))
+            qCritical("Failed to initialize EGL: 0x%x", eglGetError());
+        return S_OK;
+    });
     d->eglConfig = q_configFromGLFormat(g->eglDisplay, d->format);
 
     const EGLint flags = d->format.testOption(QSurfaceFormat::DebugContext)
@@ -142,6 +148,9 @@ bool QWinRTEGLContext::makeCurrent(QPlatformSurface *windowSurface)
     Q_D(QWinRTEGLContext);
     Q_ASSERT(windowSurface->surface()->supportsOpenGL());
 
+    if (windowSurface->surface()->surfaceClass() == QSurface::Offscreen)
+        return false;
+
     QWinRTWindow *window = static_cast<QWinRTWindow *>(windowSurface);
     if (window->eglSurface() == EGL_NO_SURFACE)
         window->createEglSurface(g->eglDisplay, d->eglConfig);
diff --git a/src/plugins/platforms/winrt/qwinrtintegration.cpp b/src/plugins/platforms/winrt/qwinrtintegration.cpp
index e94a0aa846..71e92f33ca 100644
--- a/src/plugins/platforms/winrt/qwinrtintegration.cpp
+++ b/src/plugins/platforms/winrt/qwinrtintegration.cpp
@@ -49,6 +49,8 @@
 #include <QtGui/QOpenGLContext>
 #include <qfunctions_winrt.h>
 
+#include <qpa/qplatformoffscreensurface.h>
+
 #include <functional>
 #include <wrl.h>
 #include <windows.ui.xaml.h>
@@ -124,7 +126,7 @@ QWinRTIntegration::QWinRTIntegration() : d_ptr(new QWinRTIntegrationPrivate)
                                 IID_PPV_ARGS(&d->application));
     Q_ASSERT_SUCCEEDED(hr);
     hr = d->application->add_Suspending(Callback<SuspendHandler>(this, &QWinRTIntegration::onSuspended).Get(),
-                                        &d->applicationTokens[&ICoreApplication::remove_Resuming]);
+                                        &d->applicationTokens[&ICoreApplication::remove_Suspending]);
     Q_ASSERT_SUCCEEDED(hr);
     hr = d->application->add_Resuming(Callback<ResumeHandler>(this, &QWinRTIntegration::onResume).Get(),
                                       &d->applicationTokens[&ICoreApplication::remove_Resuming]);
@@ -180,10 +182,15 @@ QWinRTIntegration::~QWinRTIntegration()
         Q_ASSERT_SUCCEEDED(hr);
     }
 #endif
+    // Do not execute this on Windows Phone as the application is already
+    // shutting down and trying to unregister suspending/resume handler will
+    // cause exceptions and assert in debug mode
+#ifndef Q_OS_WINPHONE
     for (QHash<CoreApplicationCallbackRemover, EventRegistrationToken>::const_iterator i = d->applicationTokens.begin(); i != d->applicationTokens.end(); ++i) {
         hr = (d->application.Get()->*i.key())(i.value());
         Q_ASSERT_SUCCEEDED(hr);
     }
+#endif
     destroyScreen(d->mainScreen);
     Windows::Foundation::Uninitialize();
 }
@@ -349,4 +356,14 @@ HRESULT QWinRTIntegration::onResume(IInspectable *, IInspectable *)
     return S_OK;
 }
 
+QPlatformOffscreenSurface *QWinRTIntegration::createPlatformOffscreenSurface(QOffscreenSurface *surface) const
+{
+    // This is only used for shutdown of applications.
+    // In case we do not return an empty surface the scenegraph will try
+    // to create a new native window during application exit causing crashes
+    // or assertions.
+    return new QPlatformOffscreenSurface(surface);
+}
+
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/winrt/qwinrtintegration.h b/src/plugins/platforms/winrt/qwinrtintegration.h
index 5456f6922f..31a3ce7c1c 100644
--- a/src/plugins/platforms/winrt/qwinrtintegration.h
+++ b/src/plugins/platforms/winrt/qwinrtintegration.h
@@ -98,6 +98,7 @@ public:
     QStringList themeNames() const Q_DECL_OVERRIDE;
     QPlatformTheme *createPlatformTheme(const QString &name) const Q_DECL_OVERRIDE;
 
+    QPlatformOffscreenSurface *createPlatformOffscreenSurface(QOffscreenSurface *surface) const Q_DECL_OVERRIDE;
 private:
 #ifdef Q_OS_WINPHONE
     HRESULT onBackButtonPressed(IInspectable *, ABI::Windows::Phone::UI::Input::IBackPressedEventArgs *args);
diff --git a/src/plugins/platforms/winrt/qwinrtscreen.cpp b/src/plugins/platforms/winrt/qwinrtscreen.cpp
index a642443386..997aa0d86c 100644
--- a/src/plugins/platforms/winrt/qwinrtscreen.cpp
+++ b/src/plugins/platforms/winrt/qwinrtscreen.cpp
@@ -779,6 +779,7 @@ void QWinRTScreen::addWindow(QWindow *window)
     d->visibleWindows.prepend(window);
     QWindowSystemInterface::handleWindowActivated(window, Qt::OtherFocusReason);
     handleExpose();
+    QWindowSystemInterface::flushWindowSystemEvents();
 }
 
 void QWinRTScreen::removeWindow(QWindow *window)
@@ -796,6 +797,7 @@ void QWinRTScreen::removeWindow(QWindow *window)
     if (wasTopWindow)
         QWindowSystemInterface::handleWindowActivated(window, Qt::OtherFocusReason);
     handleExpose();
+    QWindowSystemInterface::flushWindowSystemEvents();
 }
 
 void QWinRTScreen::raise(QWindow *window)