added check for index validity to OnTabButton()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45164 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/aui/auibook.cpp

@@ -3575,6 +3575,8 @@ void wxAuiNotebook::OnTabButton(wxCommandEvent& command_evt)
             else
             {
                 int main_idx = m_tabs.GetIdxFromWindow(close_wnd);
+                wxCHECK_RET( main_idx != wxNOT_FOUND, _T("no page to delete?") );
+
                 DeletePage(main_idx);
             }
         }