Render cell background in renderer only if rendering on propgrid canvas

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56930 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/propgrid/editors.cpp

@@ -691,6 +691,8 @@ void wxPropertyGrid::OnComboItemPaint( const wxPGComboBox* pCb,
 
         if ( flags & wxODCB_PAINTING_CONTROL )
             renderFlags |= wxPGCellRenderer::Control;
+        else
+            renderFlags |= wxPGCellRenderer::ChoicePopup;
 
         if ( flags & wxODCB_PAINTING_SELECTED )
             renderFlags |= wxPGCellRenderer::Selected;