there is a discrepancy between GtkMenuPositionFunc and gtk_status_icon_position_menu (the latter is intended to be dropped into the former's slot with a StatusIcon as user_data):

the push_in argument is labeled inout in gtkmenu.h (GtkMenuPositionFunc), but out in gtkstatusicon.c (gtk_status_icon_position_menu).

this becomes a problem in gir generated bindings, where it causes the functions not to "fit". (Gtk.StatusIcon.position_menu is called with (menu, push_in, my_icon) while expecting (menu, my_icon); it returns the correct (x, y, push_in) triple)

my problem with fixing it is that i'm not sure which is correct. it seems that it would be ok if the PositionFunc decided alone whether or not to set push_in, but it could just as well be passed a default value it would just pass on if it is not interested in changing it (one could argue that x and y should be inout as well in that case). the current implementation of gtk_menu_popup(_for_device) (or, rather, gtk_menu_position, from where the GtkMenuPositionFunc stored in priv->position_func is called) constantly sets pushed_in to FALSE before passing the pointer to the function. (x and y seem to be set to sensible values as well.)

a workaround exists and, for python, looks like this:

my_position_menu = lambda menu, push_in, userdata: Gtk.StatusIcon.position_menu(menu, userdata)

i can provide a patch for either solution (setting both to inout or out), i'd just need to know which way to go.

(finally, i should add that there seems to exist another problem later in popup menu positioning that causes the popup not to show at all unless i raise an exception from inside the GtkMenuPositionFunc, but that should be easier to debug once this is fixed.)