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A qualified UNIT-LEVEL proc call cannot omit a defaulted parameter

A defaulted Variant parameter works for a METHOD called from NilPy (the omitted argument arrives as tag 0 / None), but the same signature on a unit-level procedure, called qualified, does not:

import vunit
vunit.show("x")        # Nil Python: no overload matches



procedure show(const text: AnsiString; const opts: Variant = 0);

The overload probe for a qualified unit-level call requires every parameter to be supplied, so a façade written as free procedures cannot offer optional Python-shaped options — which is why lib/pcl/tkinter.pas exposes options on METHODS throughout.

Why it is filed rather than worked around

The workaround (put it on a class) is what the façade already does, so nothing is blocked today. It is filed because the asymmetry is invisible at the call site: the same declaration behaves differently depending on where it lives, and the diagnostic ("no overload matches") points at the caller rather than at the real cause.

Already fixed — verified 2026-07-31, closing

Re-measured rather than assumed still-broken: TryFillTrailingDefaults (parser.inc) already scopes its overload probe by qUnit and already fills trailing defaults for a qualified unit-level call — confirmed directly with the ticket's own repro shape (a unit exposing procedure show(const text: AnsiString; const opts: Variant = 0);, called qualified with and without the optional argument, and a two-defaulted-parameter variant) — both work today. Landed by an earlier, unrelated commit (the TryFillTrailingDefaults introduction) without this ticket being closed alongside it. Added a regression test so a future regression here is caught rather than silently re-opening this exact gap.

Gate

make test-nilpy with a unit exposing a defaulted parameter on a free procedure, called both with and without the optional argument.

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