: do-once ( guard-variable quot -- )
dupd '[ t _ set-global @ ] [ get-global ] dip unless ; inline
-SYMBOL: init-message-filter-done?
-
! Ignore the errors: on WinXP the function is missing, and is not needed.
: init-message-filter ( -- )
- init-message-filter-done? [
+ \ init-message-filter [
[ (init-message-filter) ] [ drop ] recover
] do-once ;