Ignore non-existant string selection in wxComboBox::SetValue() in read-only mode, as per the very exact docs, fixes #12329: wxComboBox can set non-existing string in read only mode

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65324 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/combobox.h

@@ -101,6 +101,8 @@ public:
 
     void OnChar( wxKeyEvent &event );
 
+    virtual void SetValue(const wxString& value);
+
     // Standard event handling
     void OnCut(wxCommandEvent& event);
     void OnCopy(wxCommandEvent& event);