bug#45333: complex command history should not save optional nil parameters

[Stefan Monnier]

>> OClosure or not doesn't make much of a difference here, I think (the
>> previous version of the code would also be quite hideous in C).
>> Why not just call `advice--cd*r`?
> Sure, that's possible, but just seems a bit backwards.

Don't know about backward, but if you don't like that dependency, you
could break it using a hook, like a `function-unwrap-function` whose
default value is `identity` and which `nadvice.el` could change to
`advice-cd*r`.


        Stefan