[Gretl-devel] 'null' list args in function package call

I'm just packaging the Gonzalo-Granger and Stock-Watson permanent-transitory decomposition functions as requested recently on the list, and I encountered what looks to me like a regression with respect to earlier (maybe much earlier) gretl versions: In my package two list arguments of the public function are optional, i.e. the default value in the package is 'null'. This shows up fine in the GUI function call window, at least at first. But after defining a new list for *another* argument, this newly created list is entered into *all* list argument fields, and the 'null' keyword also disappears from the respective drop-down menus. (I can manually write the word 'null' in the field ok, though.) It would be nice if 'null' were unaffected and preserved in this case. thanks, sven