6 files changed, 30 insertions, 11 deletions
diff --git a/src/widgets/kernel/qopenglwidget.cpp b/src/widgets/kernel/qopenglwidget.cpp
index 1522b065a7..7051f970ff 100644
--- a/src/widgets/kernel/qopenglwidget.cpp
+++ b/src/widgets/kernel/qopenglwidget.cpp
@@ -1172,8 +1172,7 @@ void QOpenGLWidget::resizeEvent(QResizeEvent *e)
 
     d->recreateFbo();
     resizeGL(width(), height());
-    d->invokeUserPaint();
-    d->resolveSamples();
+    d->sendPaintEvent(QRect(QPoint(0, 0), size()));
 }
 
 /*!
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index e8169d0bd1..308403175a 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -271,6 +271,9 @@ QWidgetPrivate::QWidgetPrivate(int version)
 #ifndef QT_NO_IM
       , inheritsInputMethodHints(0)
 #endif
+#ifndef QT_NO_OPENGL
+      , renderToTextureReallyDirty(1)
+#endif
 #if defined(Q_OS_WIN)
       , noPaintOnScreen(0)
 #endif
@@ -5560,7 +5563,7 @@ void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QP
                      << "geometry ==" << QRect(q->mapTo(q->window(), QPoint(0, 0)), q->size());
 #endif
 
-            bool grabbed = false;
+            bool skipPaintEvent = false;
 #ifndef QT_NO_OPENGL
             if (renderToTexture) {
                 // This widget renders into a texture which is composed later. We just need to
@@ -5574,14 +5577,18 @@ void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QP
                     } else {
                         // We are not drawing to a backingstore: fall back to QImage
                         p.drawImage(q->rect(), grabFramebuffer());
-                        grabbed = true;
+                        skipPaintEvent = true;
                     }
                     endBackingStorePainting();
                 }
+                if (renderToTextureReallyDirty)
+                    renderToTextureReallyDirty = 0;
+                else
+                    skipPaintEvent = true;
             }
 #endif // QT_NO_OPENGL
 
-            if (!grabbed) {
+            if (!skipPaintEvent) {
                 //actually send the paint event
                 sendPaintEvent(toBePainted);
             }
diff --git a/src/widgets/kernel/qwidget_p.h b/src/widgets/kernel/qwidget_p.h
index a78cf099ac..7eb8d048b3 100644
--- a/src/widgets/kernel/qwidget_p.h
+++ b/src/widgets/kernel/qwidget_p.h
@@ -743,6 +743,9 @@ public:
 #ifndef QT_NO_IM
     uint inheritsInputMethodHints : 1;
 #endif
+#ifndef QT_NO_OPENGL
+    uint renderToTextureReallyDirty : 1;
+#endif
 
     // *************************** Platform specific ************************************
 #if defined(Q_OS_WIN)
diff --git a/src/widgets/kernel/qwidgetbackingstore.cpp b/src/widgets/kernel/qwidgetbackingstore.cpp
index 90311b0f0a..a108dcf03b 100644
--- a/src/widgets/kernel/qwidgetbackingstore.cpp
+++ b/src/widgets/kernel/qwidgetbackingstore.cpp
@@ -1000,6 +1000,16 @@ void QPlatformTextureListWatcher::onLockStatusChanged(bool locked)
     if (!isLocked())
         m_backingStore->sync();
 }
+
+#else
+
+static QPlatformTextureList *widgetTexturesFor(QWidget *tlw, QWidget *widget)
+{
+    Q_UNUSED(tlw);
+    Q_UNUSED(widget);
+    return Q_NULLPTR;
+}
+
 #endif // QT_NO_OPENGL
 
 static inline bool discardSyncRequest(QWidget *tlw, QTLWExtra *tlwExtra)
@@ -1220,6 +1230,9 @@ void QWidgetBackingStore::doSync()
             QWidget *w = static_cast<QWidget *>(tl->source(i));
             if (dirtyRenderToTextureWidgets.contains(w)) {
                 const QRect rect = tl->geometry(i); // mapped to the tlw already
+                // Set a flag to indicate that the paint event for this
+                // render-to-texture widget must not to be optimized away.
+                w->d_func()->renderToTextureReallyDirty = 1;
                 dirty += rect;
                 toClean += rect;
             }
diff --git a/src/widgets/util/qsystemtrayicon.cpp b/src/widgets/util/qsystemtrayicon.cpp
index 20f5c95ae9..47bc88cb43 100644
--- a/src/widgets/util/qsystemtrayicon.cpp
+++ b/src/widgets/util/qsystemtrayicon.cpp
@@ -284,12 +284,6 @@ bool QSystemTrayIcon::isVisible() const
 */
 bool QSystemTrayIcon::event(QEvent *e)
 {
-#if defined(Q_DEAD_CODE_FROM_QT4_X11)
-    if (e->type() == QEvent::ToolTip) {
-        Q_D(QSystemTrayIcon);
-        return d->sys->deliverToolTipEvent(e);
-    }
-#endif
     return QObject::event(e);
 }
 
diff --git a/src/widgets/util/qsystemtrayicon_x11.cpp b/src/widgets/util/qsystemtrayicon_x11.cpp
index e50b0bd12c..13d58acebd 100644
--- a/src/widgets/util/qsystemtrayicon_x11.cpp
+++ b/src/widgets/util/qsystemtrayicon_x11.cpp
@@ -196,6 +196,9 @@ void QSystemTrayIconSys::mouseDoubleClickEvent(QMouseEvent *ev)
 bool QSystemTrayIconSys::event(QEvent *e)
 {
     switch (e->type()) {
+    case QEvent::ToolTip:
+        QApplication::sendEvent(q, e);
+        break;
 #ifndef QT_NO_WHEELEVENT
     case QEvent::Wheel:
         return QApplication::sendEvent(q, e);