runtime-undef not folding

Some examples:

$ perl -MO=Deparse -e'"" || 1'
'???';
-e syntax OK

- - - - -

$ perl -MO=Deparse -e'undef || 1'
'???' unless undef;
-e syntax OK

- - - - -

$ perl -MO=Deparse -e'
   use constant F => undef;
   F and 1;
   undef and 2;
'
use constant ('F', undef);
'???';
'???' if undef;
-e syntax OK

- - - - -

So compile-time-undef folds,
but runtime-undef doesn't.

(which initially surprised me, but now looks fine with me)

-- Ruud

• runtime-undef not folding by "Ruud H.G. van Tol" via perl5-porters