1 files changed, 9 insertions, 4 deletions
diff --git a/Source/WebKit/qt/WebCoreSupport/PageClientQt.cpp b/Source/WebKit/qt/WebCoreSupport/PageClientQt.cpp
index 92ab84b64..369307cba 100644
--- a/Source/WebKit/qt/WebCoreSupport/PageClientQt.cpp
+++ b/Source/WebKit/qt/WebCoreSupport/PageClientQt.cpp
@@ -282,11 +282,16 @@ void PageClientQGraphicsWidget::setRootGraphicsLayer(GraphicsLayer* layer)
 {
     if (layer) {
         TextureMapperLayerClient = adoptPtr(new TextureMapperLayerClientQt(page->mainFrame(), layer));
-#if USE(TEXTURE_MAPPER_GL)
+#if USE(TEXTURE_MAPPER_GL) && defined(QT_OPENGL_LIB)
         QGraphicsView* graphicsView = view->scene()->views()[0];
-        if (graphicsView && graphicsView->viewport() && graphicsView->viewport()->inherits("QGLWidget")) {
-            TextureMapperLayerClient->setTextureMapper(TextureMapper::create(TextureMapper::OpenGLMode));
-            return;
+        if (graphicsView && graphicsView->viewport()) {
+            QGLWidget* glWidget = qobject_cast<QGLWidget*>(graphicsView->viewport());
+            if (glWidget) {
+                // The GL context belonging to the QGLWidget viewport must be current when TextureMapper is being created.
+                glWidget->makeCurrent();
+                TextureMapperLayerClient->setTextureMapper(TextureMapper::create(TextureMapper::OpenGLMode));
+                return;
+            }
         }
 #endif
         TextureMapperLayerClient->setTextureMapper(TextureMapper::create());