Bail out in composeAndFlush when makeCurrent fails

And show a warning so we have a chance of knowing what
happened.

Change-Id: I9ddf3842b7d19946876ac1a2375611e8c13bbb9a
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp
index 0d550887d9..8e50059ca4 100644
--- a/src/gui/painting/qplatformbackingstore.cpp
+++ b/src/gui/painting/qplatformbackingstore.cpp
@@ -237,7 +237,11 @@ void QPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion &regi
 {
     Q_UNUSED(offset);
 
-    context->makeCurrent(window);
+    if (!context->makeCurrent(window)) {
+        qWarning("composeAndFlush: makeCurrent() failed");
+        return;
+    }
+
     QOpenGLFunctions *funcs = context->functions();
     funcs->glViewport(0, 0, window->width() * window->devicePixelRatio(), window->height() * window->devicePixelRatio());
     funcs->glClearColor(0, 0, 0, translucentBackground ? 0 : 1);