Avoid binding reference to NULL pointer when wxUSE_VALIDATORS==0

Undefined behavior sanitizer complains about it

include/wx/validate.h

@@ -97,8 +97,6 @@ private:
     wxDECLARE_NO_ASSIGN_CLASS(wxValidator);
 };
 
-extern WXDLLIMPEXP_DATA_CORE(const wxValidator) wxDefaultValidator;
-
 #define wxVALIDATOR_PARAM(val) val
 
 #else // !wxUSE_VALIDATORS
@@ -107,13 +105,13 @@ extern WXDLLIMPEXP_DATA_CORE(const wxValidator) wxDefaultValidator;
     // a wxValidator parameter to avoid using "#if wxUSE_VALIDATORS"
     // everywhere
     class WXDLLIMPEXP_FWD_CORE wxValidator;
-    static const wxValidator* const wxDefaultValidatorPtr = NULL;
-    #define wxDefaultValidator (*wxDefaultValidatorPtr)
 
     // this macro allows to avoid warnings about unused parameters when
     // wxUSE_VALIDATORS == 0
     #define wxVALIDATOR_PARAM(val)
 #endif // wxUSE_VALIDATORS/!wxUSE_VALIDATORS
 
+extern WXDLLIMPEXP_DATA_CORE(const wxValidator) wxDefaultValidator;
+
 #endif // _WX_VALIDATE_H_
 

src/common/validate.cpp

@@ -23,8 +23,6 @@
     #include "wx/window.h"
 #endif
 
-const wxValidator wxDefaultValidator;
-
 wxIMPLEMENT_DYNAMIC_CLASS(wxValidator, wxEvtHandler);
 
 // VZ: personally, I think true would be more appropriate - these bells are
@@ -39,6 +37,10 @@ wxValidator::wxValidator()
 wxValidator::~wxValidator()
 {
 }
+#else
 
-#endif
-  // wxUSE_VALIDATORS
+class WXDLLIMPEXP_CORE wxValidator { };
+
+#endif // wxUSE_VALIDATORS
+
+const wxValidator wxDefaultValidator;