EGLFS: Fix plugin destruction (again)

The previous patch was flawed since by the time the QEglPlatformIntegration
destructor was called the virtual function table did not point to the methods in
QEglFsPlatformIntegration any more.

Change-Id: I310e5e3e734a22b44645ba912b579f193bcfae86
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>

src/gui/kernel/qguiapplication.cpp

@@ -1391,6 +1391,8 @@ QGuiApplicationPrivate::~QGuiApplicationPrivate()
     }
 #endif
 
+    platform_integration->destroy();
+
     delete platform_theme;
     platform_theme = 0;
     delete platform_integration;

src/gui/kernel/qplatformintegration.cpp

@@ -323,6 +323,16 @@ void QPlatformIntegration::initialize()
 {
 }
 
+/*!
+  Called before the platform integration is deleted. Useful when cleanup relies on virtual
+  functions.
+
+  \since 5.5
+*/
+void QPlatformIntegration::destroy()
+{
+}
+
 /*!
   Returns the platforms input context.
 

src/gui/kernel/qplatformintegration.h

@@ -109,6 +109,7 @@ public:
 // Event dispatcher:
     virtual QAbstractEventDispatcher *createEventDispatcher() const = 0;
     virtual void initialize();
+    virtual void destroy();
 
 //Deeper window system integrations
     virtual QPlatformFontDatabase *fontDatabase() const;

src/platformsupport/eglconvenience/qeglplatformintegration.cpp

@@ -95,15 +95,7 @@ QEGLPlatformIntegration::QEGLPlatformIntegration()
 
 QEGLPlatformIntegration::~QEGLPlatformIntegration()
 {
-    foreach (QWindow *w, qGuiApp->topLevelWindows())
-        w->destroy();
 
-    delete m_screen;
-
-    if (m_display != EGL_NO_DISPLAY)
-        eglTerminate(m_display);
-
-    destroy();
 }
 
 void QEGLPlatformIntegration::initialize()
@@ -126,7 +118,13 @@ void QEGLPlatformIntegration::initialize()
 
 void QEGLPlatformIntegration::destroy()
 {
+    foreach (QWindow *w, qGuiApp->topLevelWindows())
+        w->destroy();
 
+    delete m_screen;
+
+    if (m_display != EGL_NO_DISPLAY)
+        eglTerminate(m_display);
 }
 
 QAbstractEventDispatcher *QEGLPlatformIntegration::createEventDispatcher() const

src/platformsupport/eglconvenience/qeglplatformintegration_p.h

@@ -65,7 +65,7 @@ public:
     ~QEGLPlatformIntegration();
 
     void initialize() Q_DECL_OVERRIDE;
-    virtual void destroy();
+    void destroy() Q_DECL_OVERRIDE;
 
     QEGLPlatformScreen *screen() const { return m_screen; }
     EGLDisplay display() const { return m_display; }

src/plugins/platforms/eglfs/qeglfsintegration.cpp

@@ -88,6 +88,7 @@ void QEglFSIntegration::initialize()
 
 void QEglFSIntegration::destroy()
 {
+    QEGLPlatformIntegration::destroy();
     QEglFSHooks::hooks()->platformDestroy();
 }