Fixes #10437 (wxDataObjectComposite::Add may add objects having data formats that already exist in the composite object)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58549 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/dataobj.h

@@ -297,7 +297,7 @@ public:
 
 protected:
     // returns the pointer to the object which supports this format or NULL
-    wxDataObjectSimple *GetObject(const wxDataFormat& format) const;
+    wxDataObjectSimple *GetObject(const wxDataFormat& format, wxDataObjectBase::Direction dir=Get) const;
 
 private:
     // the list of all (simple) data objects whose formats we support