16 files changed, 52 insertions, 21 deletions
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index 7e291e9050..86edb9bd28 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -439,7 +439,7 @@ QList<int> QPlatformIntegration::possibleKeys(const QKeyEvent *) const
   This adds the screen to QGuiApplication::screens(), and emits the
   QGuiApplication::screenAdded() signal.
 
-  The screen is automatically removed when the QPlatformScreen is destroyed.
+  The screen should be deleted by calling QPlatformIntegration::destroyScreen().
 */
 void QPlatformIntegration::screenAdded(QPlatformScreen *ps)
 {
@@ -449,6 +449,22 @@ void QPlatformIntegration::screenAdded(QPlatformScreen *ps)
     emit qGuiApp->screenAdded(screen);
 }
 
+/*!
+  Should be called by the implementation whenever a screen is removed.
+
+  This removes the screen from QGuiApplication::screens(), and deletes it.
+
+  Failing to call this and manually deleting the QPlatformScreen instead may
+  lead to a crash due to a pure virtual call.
+*/
+void QPlatformIntegration::destroyScreen(QPlatformScreen *screen)
+{
+    QGuiApplicationPrivate::screen_list.removeOne(screen->d_func()->screen);
+    delete screen->d_func()->screen;
+    screen->d_func()->screen = Q_NULLPTR;
+    delete screen;
+}
+
 QStringList QPlatformIntegration::themeNames() const
 {
     return QStringList();
diff --git a/src/gui/kernel/qplatformintegration.h b/src/gui/kernel/qplatformintegration.h
index ccbe4cc73d..dbef939b8b 100644
--- a/src/gui/kernel/qplatformintegration.h
+++ b/src/gui/kernel/qplatformintegration.h
@@ -171,6 +171,7 @@ public:
 
 protected:
     void screenAdded(QPlatformScreen *screen);
+    void destroyScreen(QPlatformScreen *screen);
 };
 
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformscreen.cpp b/src/gui/kernel/qplatformscreen.cpp
index 71710d1cb1..fa6d785b04 100644
--- a/src/gui/kernel/qplatformscreen.cpp
+++ b/src/gui/kernel/qplatformscreen.cpp
@@ -52,9 +52,11 @@ QPlatformScreen::QPlatformScreen()
 QPlatformScreen::~QPlatformScreen()
 {
     Q_D(QPlatformScreen);
-
-    QGuiApplicationPrivate::screen_list.removeOne(d->screen);
-    delete d->screen;
+    if (d->screen) {
+        qWarning("Manually deleting a QPlatformScreen. Call QPlatformIntegration::destroyScreen instead.");
+        QGuiApplicationPrivate::screen_list.removeOne(d->screen);
+        delete d->screen;
+    }
 }
 
 /*!
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 72bd09625a..180cb23669 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -337,7 +337,7 @@ QCocoaIntegration::~QCocoaIntegration()
 
     // Delete screens in reverse order to avoid crash in case of multiple screens
     while (!mScreens.isEmpty()) {
-        delete mScreens.takeLast();
+        destroyScreen(mScreens.takeLast());
     }
 
     clearToolbars();
@@ -397,7 +397,7 @@ void QCocoaIntegration::updateScreens()
     // Now the leftovers in remainingScreens are no longer current, so we can delete them.
     foreach (QCocoaScreen* screen, remainingScreens) {
         mScreens.removeOne(screen);
-        delete screen;
+        destroyScreen(screen);
     }
     // All screens in mScreens are siblings, because we ignored the mirrors.
     foreach (QCocoaScreen* screen, mScreens)
diff --git a/src/plugins/platforms/ios/qiosintegration.mm b/src/plugins/platforms/ios/qiosintegration.mm
index 461f160892..ff4b753cc1 100644
--- a/src/plugins/platforms/ios/qiosintegration.mm
+++ b/src/plugins/platforms/ios/qiosintegration.mm
@@ -120,7 +120,7 @@ QIOSIntegration::~QIOSIntegration()
     m_inputContext = 0;
 
     foreach (QScreen *screen, QGuiApplication::screens())
-        delete screen->handle();
+        destroyScreen(screen->handle());
 
     delete m_platformServices;
     m_platformServices = 0;
diff --git a/src/plugins/platforms/kms/qkmsintegration.cpp b/src/plugins/platforms/kms/qkmsintegration.cpp
index d94d7d9aaa..5ad58ba54f 100644
--- a/src/plugins/platforms/kms/qkmsintegration.cpp
+++ b/src/plugins/platforms/kms/qkmsintegration.cpp
@@ -74,7 +74,7 @@ QKmsIntegration::~QKmsIntegration()
         delete device;
     }
     foreach (QPlatformScreen *screen, m_screens) {
-        delete screen;
+        destroyScreen(screen);
     }
     delete m_fontDatabase;
     delete m_vtHandler;
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp b/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
index cb870847f2..b0d99e80c1 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
+++ b/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
@@ -57,7 +57,7 @@ QLinuxFbIntegration::QLinuxFbIntegration(const QStringList &paramList)
 
 QLinuxFbIntegration::~QLinuxFbIntegration()
 {
-    delete m_primaryScreen;
+    destroyScreen(m_primaryScreen);
 }
 
 void QLinuxFbIntegration::initialize()
diff --git a/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp b/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp
index 0b12e62cc1..3fbed1ec26 100644
--- a/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp
+++ b/src/plugins/platforms/minimalegl/qminimaleglintegration.cpp
@@ -60,7 +60,7 @@ QMinimalEglIntegration::QMinimalEglIntegration()
 
 QMinimalEglIntegration::~QMinimalEglIntegration()
 {
-    delete mScreen;
+    destroyScreen(mScreen);
 }
 
 bool QMinimalEglIntegration::hasCapability(QPlatformIntegration::Capability cap) const
diff --git a/src/plugins/platforms/openwfd/qopenwfdintegration.cpp b/src/plugins/platforms/openwfd/qopenwfdintegration.cpp
index 1e29fcc9b1..26bdd14327 100644
--- a/src/plugins/platforms/openwfd/qopenwfdintegration.cpp
+++ b/src/plugins/platforms/openwfd/qopenwfdintegration.cpp
@@ -133,3 +133,8 @@ void QOpenWFDIntegration::addScreen(QOpenWFDScreen *screen)
 {
     screenAdded(screen);
 }
+
+void QOpenWFDIntegration::destroyScreen(QOpenWFDScreen *screen)
+{
+    QPlatformIntegration::destroyScreen(screen);
+}
diff --git a/src/plugins/platforms/openwfd/qopenwfdintegration.h b/src/plugins/platforms/openwfd/qopenwfdintegration.h
index 6c086b73be..9243205caa 100644
--- a/src/plugins/platforms/openwfd/qopenwfdintegration.h
+++ b/src/plugins/platforms/openwfd/qopenwfdintegration.h
@@ -63,6 +63,7 @@ public:
     QPlatformPrinterSupport *printerSupport() const;
 
     void addScreen(QOpenWFDScreen *screen);
+    void destroyScreen(QOpenWFDScreen *screen);
 private:
     QList<QPlatformScreen *> mScreens;
     QList<QOpenWFDDevice *>mDevices;
diff --git a/src/plugins/platforms/openwfd/qopenwfdport.cpp b/src/plugins/platforms/openwfd/qopenwfdport.cpp
index 0bdc6b2d4b..b643644800 100644
--- a/src/plugins/platforms/openwfd/qopenwfdport.cpp
+++ b/src/plugins/platforms/openwfd/qopenwfdport.cpp
@@ -140,7 +140,7 @@ void QOpenWFDPort::detach()
     mAttached = false;
     mOn = false;
 
-    delete mScreen;
+    mDevice->integration()->destroyScreen(mScreen);
 
     wfdDestroyPipeline(mDevice->handle(),mPipeline);
     mPipelineId = WFD_INVALID_PIPELINE_ID;
diff --git a/src/plugins/platforms/qnx/qqnxintegration.cpp b/src/plugins/platforms/qnx/qqnxintegration.cpp
index 6a3cd902af..dba4ba67a8 100644
--- a/src/plugins/platforms/qnx/qqnxintegration.cpp
+++ b/src/plugins/platforms/qnx/qqnxintegration.cpp
@@ -554,7 +554,7 @@ void QQnxIntegration::removeDisplay(QQnxScreen *screen)
     Q_CHECK_PTR(screen);
     Q_ASSERT(m_screens.contains(screen));
     m_screens.removeAll(screen);
-    screen->deleteLater();
+    destroyScreen(screen);
 }
 
 void QQnxIntegration::destroyDisplays()
diff --git a/src/plugins/platforms/windows/qwindowsintegration.h b/src/plugins/platforms/windows/qwindowsintegration.h
index d1617eaa3c..7fb37bc1f1 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.h
+++ b/src/plugins/platforms/windows/qwindowsintegration.h
@@ -94,6 +94,7 @@ public:
     static QWindowsIntegration *instance();
 
     inline void emitScreenAdded(QPlatformScreen *s) { screenAdded(s); }
+    inline void emitDestroyScreen(QPlatformScreen *s) { destroyScreen(s); }
 
     unsigned options() const;
 
diff --git a/src/plugins/platforms/windows/qwindowsscreen.cpp b/src/plugins/platforms/windows/qwindowsscreen.cpp
index fd57d9ee61..79219e361a 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.cpp
+++ b/src/plugins/platforms/windows/qwindowsscreen.cpp
@@ -462,7 +462,7 @@ void QWindowsScreenManager::removeScreen(int index)
         if (movedWindowCount)
             QWindowSystemInterface::flushWindowSystemEvents();
     }
-    delete m_screens.takeAt(index);
+    QWindowsIntegration::instance()->emitDestroyScreen(m_screens.takeAt(index));
 }
 
 /*!
@@ -497,4 +497,11 @@ bool QWindowsScreenManager::handleScreenChanges()
     return true;
 }
 
+void QWindowsScreenManager::clearScreens()
+{
+    // Delete screens in reverse order to avoid crash in case of multiple screens
+    while (!m_screens.isEmpty())
+        QWindowsIntegration::instance()->emitDestroyScreen(m_screens.takeLast());
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/windows/qwindowsscreen.h b/src/plugins/platforms/windows/qwindowsscreen.h
index aa1408358b..924912dbc2 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.h
+++ b/src/plugins/platforms/windows/qwindowsscreen.h
@@ -127,11 +127,7 @@ public:
 
     QWindowsScreenManager();
 
-    inline void clearScreens() {
-        // Delete screens in reverse order to avoid crash in case of multiple screens
-        while (!m_screens.isEmpty())
-            delete m_screens.takeLast();
-    }
+    void clearScreens();
 
     bool handleScreenChanges();
     bool handleDisplayChange(WPARAM wParam, LPARAM lParam);
diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 2e429939ba..08b414e82e 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -240,11 +240,12 @@ void QXcbConnection::updateScreens()
         ++xcbScreenNumber;
     } // for each xcb screen
 
+    QXcbIntegration *integration = static_cast<QXcbIntegration *>(QGuiApplicationPrivate::platformIntegration());
     // Now activeScreens is the complete set of screens which are active at this time.
     // Delete any existing screens which are not in activeScreens
     for (int i = m_screens.count() - 1; i >= 0; --i) {
         if (!activeScreens.contains(m_screens[i])) {
-            delete m_screens[i];
+            integration->destroyScreen(m_screens.at(i));
             m_screens.removeAt(i);
         }
     }
@@ -261,7 +262,7 @@ void QXcbConnection::updateScreens()
     // Now that they are in the right order, emit the added signals for new screens only
     foreach (QXcbScreen* screen, m_screens)
         if (newScreens.contains(screen))
-            ((QXcbIntegration*)QGuiApplicationPrivate::platformIntegration())->screenAdded(screen);
+            integration->screenAdded(screen);
 }
 
 QXcbConnection::QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGrabServer, const char *displayName)
@@ -400,9 +401,10 @@ QXcbConnection::~QXcbConnection()
 
     delete m_reader;
 
+    QXcbIntegration *integration = static_cast<QXcbIntegration *>(QGuiApplicationPrivate::platformIntegration());
     // Delete screens in reverse order to avoid crash in case of multiple screens
     while (!m_screens.isEmpty())
-        delete m_screens.takeLast();
+        integration->destroyScreen(m_screens.takeLast());
 
 #ifdef XCB_USE_XLIB
     XCloseDisplay((Display *)m_xlib_display);