Avoid crashing when there is no QWindowsIntegration anymore

When destroying the QWindowsIntegration, the global instance is set to
null in the destructor. This is followed by a lot of additional steps
when destroying the members. Some of that cleanup calls to
staticOpenGLContext() which was not handling the case of the integration
global instance being null.

Change-Id: Ib74faf491d4c81635934547968ec91e9dceec6e7
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index 62df7918c1..9fd18a1ef4 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -420,7 +420,10 @@ QOpenGLContext::OpenGLModuleType QWindowsIntegration::openGLModuleType()
 
 QWindowsStaticOpenGLContext *QWindowsIntegration::staticOpenGLContext()
 {
-    QWindowsIntegrationPrivate *d = QWindowsIntegration::instance()->d.data();
+    QWindowsIntegration *integration = QWindowsIntegration::instance();
+    if (!integration)
+        return 0;
+    QWindowsIntegrationPrivate *d = integration->d.data();
     if (d->m_staticOpenGLContext.isNull())
         d->m_staticOpenGLContext = QSharedPointer<QWindowsStaticOpenGLContext>(QWindowsStaticOpenGLContext::create());
     return d->m_staticOpenGLContext.data();