Reset wxPGEditor singleton instance pointers in dtors. This is useful if wxPropertyGrid is being accessed from an external main loop.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65666 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/propgrid/propgrid.cpp

@@ -235,6 +235,10 @@ wxPGGlobalVarsClass::~wxPGGlobalVarsClass()
         delete ((wxPGEditor*)vt_it->second);
     }
 
+    // Make sure the global pointers have been reset
+    wxASSERT(wxPG_EDITOR(TextCtrl) == NULL);
+    wxASSERT(wxPG_EDITOR(ChoiceAndButton) == NULL);
+
     delete wxPGProperty::sm_wxPG_LABEL;
 }