CanvasRenderJob: check if QOpenGLContext::currentContext() is NULL

Using a Canvas3D inside a QQuickWidget, for some reason sometimes QOpenGLContext::currentContext() is NULL,
that causes a crash in CanvasRenderJob.
The easy fix that seems to work is to just check QOpenGLContext::currentContext() if is NULL and so prevent the application to crash

Task-number: QTBUG-54466
Change-Id: Icbc0e1500b06d3768bd238e54533b20f72e31500
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/imports/qtcanvas3d/renderjob.cpp b/src/imports/qtcanvas3d/renderjob.cpp
index 754aacb..4719251 100644
--- a/src/imports/qtcanvas3d/renderjob.cpp
+++ b/src/imports/qtcanvas3d/renderjob.cpp
@@ -82,7 +82,9 @@ void CanvasRenderJob::run()
         QSurface *oldSurface(0);
         if (!m_renderer->usingQtContext()) {
             oldContext = QOpenGLContext::currentContext();
-            oldSurface = oldContext->surface();
+            if (oldContext)
+                oldSurface = oldContext->surface();
+
             m_renderer->makeCanvasContextCurrent();
         }