4 files changed, 28 insertions, 13 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 2a3ce54..32534aa 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -3810,6 +3810,11 @@ bool QGLWidget::event(QEvent *e)
     }
 
 #if defined(QT_OPENGL_ES)
+    // A re-parent is likely to destroy the X11 window and re-create it. It is important
+    // that we free the EGL surface _before_ the winID changes - otherwise we can leak.
+    if (e->type() == QEvent::ParentAboutToChange)
+        d->glcx->d_func()->destroyEglSurfaceForDevice();
+
     if ((e->type() == QEvent::ParentChange) || (e->type() == QEvent::WindowStateChange)) {
         // The window may have been re-created during re-parent or state change - if so, the EGL
         // surface will need to be re-created.
diff --git a/src/opengl/qgl.h b/src/opengl/qgl.h
index 079953f..2076c46 100644
--- a/src/opengl/qgl.h
+++ b/src/opengl/qgl.h
@@ -546,6 +546,7 @@ private:
     friend class QGLPixelBuffer;
     friend class QGLPixelBufferPrivate;
     friend class QGLContext;
+    friend class QGLContextPrivate;
     friend class QGLOverlayWidget;
     friend class QOpenGLPaintEngine;
     friend class QGLPaintDevice;
diff --git a/src/opengl/qgl_egl.cpp b/src/opengl/qgl_egl.cpp
index fbf0349..839e8eb 100644
--- a/src/opengl/qgl_egl.cpp
+++ b/src/opengl/qgl_egl.cpp
@@ -142,19 +142,7 @@ void QGLContext::reset()
     d->cleanup();
     doneCurrent();
     if (d->eglContext) {
-        if (d->eglSurface != EGL_NO_SURFACE) {
-#ifdef Q_WS_X11
-            // Make sure we don't call eglDestroySurface on a surface which
-            // was created for a different winId:
-            if (d->paintDevice->devType() == QInternal::Widget) {
-                QGLWidget* w = static_cast<QGLWidget*>(d->paintDevice);
-
-                if (w->d_func()->eglSurfaceWindowId == w->winId())
-                    eglDestroySurface(d->eglContext->display(), d->eglSurface);
-            } else
-#endif
-                eglDestroySurface(d->eglContext->display(), d->eglSurface);
-        }
+        d->destroyEglSurfaceForDevice();
         delete d->eglContext;
     }
     d->eglContext = 0;
@@ -198,6 +186,26 @@ void QGLContext::swapBuffers() const
     d->eglContext->swapBuffers(d->eglSurface);
 }
 
+void QGLContextPrivate::destroyEglSurfaceForDevice()
+{
+    if (eglSurface != EGL_NO_SURFACE) {
+#ifdef Q_WS_X11
+        // Make sure we don't call eglDestroySurface on a surface which
+        // was created for a different winId:
+        if (paintDevice->devType() == QInternal::Widget) {
+            QGLWidget* w = static_cast<QGLWidget*>(paintDevice);
+
+            if (w->d_func()->eglSurfaceWindowId == w->winId())
+                eglDestroySurface(eglContext->display(), eglSurface);
+            else
+                qWarning("WARNING: Potential EGL surface leak!");
+        } else
+#endif
+            eglDestroySurface(eglContext->display(), eglSurface);
+        eglSurface = EGL_NO_SURFACE;
+    }
+}
+
 void QGLWidget::setMouseTracking(bool enable)
 {
     QWidget::setMouseTracking(enable);
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index 11770d3..99c0f33 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -288,6 +288,7 @@ public:
 #if defined(QT_OPENGL_ES)
     QEglContext *eglContext;
     EGLSurface eglSurface;
+    void destroyEglSurfaceForDevice();
 #elif defined(Q_WS_X11) || defined(Q_WS_MAC)
     void* cx;
 #endif