QQuickWindow: Run render jobs when there is a render control in NoStage

When running a QML application with using Canvas3D component inside a
QQuickWidget, the Canvas3D is not rendered. This is due to no scheduled
OpenGL commands with RenderStage == NoStage are actually executed when
there is a render control instead of a window manager.

Fixes: QTBUG-51993
Change-Id: I33323893cd6144187feccb1c6bcd010eff0fff6d
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 10 insertions, 2 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index c6bfcaa647..bd01e9b3ce 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -4828,10 +4828,18 @@ void QQuickWindow::scheduleRenderJob(QRunnable *job, RenderStage stage)
     } else if (stage == AfterSwapStage) {
         d->afterSwapJobs << job;
     } else if (stage == NoStage) {
-        if (isExposed())
+        if (d->renderControl && openglContext()
+#if QT_CONFIG(opengl)
+            && openglContext()->thread() == QThread::currentThread()
+#endif
+            ) {
+            job->run();
+            delete job;
+        } else if (isExposed()) {
             d->windowManager->postJob(this, job);
-        else
+        } else {
             delete job;
+        }
     }
     d->renderJobMutex.unlock();
 }