make the path absolute before using it with gtk_file_chooser_set_current_folder() (patch 1753796)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@47477 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/filedlg.cpp

@@ -237,6 +237,7 @@ wxFileDialog::wxFileDialog(wxWindow *parent, const wxString& message,
         fn.AssignDir(defaultDir);
 
     // set the initial file name and/or directory
+    fn.MakeAbsolute(); // GTK+ needs absolute path
     const wxString dir = fn.GetPath();
     if ( !dir.empty() )
     {