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

[Drew Adams]

> > (Which reminds me -- I've always found it odd that that function
> > lives in help.el, and is in Emacs Lisp instead of C.

I don't care where it lives, but why should you
even consider moving it to C?  Is this to solve
some performance problem?  Leave it in Lisp, so
users can modify or otherwise improve it.

More should be moved from C to Lisp, not vice versa.

> > It is, after all, used by eldoc etc,

So move it somewhere else in Lisp.

> and it'd probably be nice if it were more efficient.)

That's never been a good enough reason to move something
to C.  Not unless there's a real performance problem
that needs to be solved by doing so (i.e., can't be
solved some other, better way).

> So I started taking a stab at this to see whether there's 
> any gains to be had, and I've now basically rewritten it in C.

Gag.

> And, yes, I think it makes sense, because we can avoid
> at least some garbage generating functions without
> contorting ourselves too much.

Stats?  The problem is ________.  ?

> this help-function-arglist rewrite is totally irrelevant
> for this bug report.

For what problem do you think it _is_ relevant?  Why?