Fix crash in QVGSharedContext shutdown

The reference count was reducing down to zero during paint engine
cleanup when we weren't ready to destroy the context.  Artificially
increase it to prevent the early context destroy.

Reviewed-by: Sarah Smith

1 files changed, 4 insertions, 0 deletions

diff --git a/src/openvg/qwindowsurface_vgegl.cpp b/src/openvg/qwindowsurface_vgegl.cpp
index 1365344088..06759d4f8d 100644
--- a/src/openvg/qwindowsurface_vgegl.cpp
+++ b/src/openvg/qwindowsurface_vgegl.cpp
@@ -139,6 +139,10 @@ QVGSharedContext::QVGSharedContext()
 
 QVGSharedContext::~QVGSharedContext()
 {
+    // Don't accidentally destroy the QEglContext if the reference
+    // count falls to zero while deleting the paint engine.
+    ++refCount;
+
     if (context)
         qt_vg_make_current(context, qt_vg_shared_surface());
     delete engine;