Another Dash vs. hyphen bug?

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

The split doesn't work as expected in the first case below, probably
because the hyphen has been tokenized (or has failed to be
un-tokenized).

% print -r -- ${(@s.-.):-A-B}
A-B
% print -r -- ${(@s.-.):-A\-B}
A B
% ab=A-B
% print -r -- ${(@s.-.):-$ab}
A B
%

I'm not exactly sure what should happen in this case:

% print -r -- ${(@~s.-.):-A-B}
A B
%