>> Here is a non-intrusive patch that doesn't change the default behavior
>> while provides navigation of completions from the minibuffer
>> like web browsers do on their address bar.
>
> [...]
>
>> +  "M-<up>"    #'minibuffer-completion-previous
>> +  "M-<down>"  #'minibuffer-completion-next
>> +  "M-RET"     #'minibuffer-completion-choose)
>
> If I'm reading this patch correctly, then this looks like just what I've
> wanted for decades.  😀
>
> [...]
>
>> +    (choose-completion nil t t)))
>
> But this doesn't seem quite correct?  The function only takes a single
> parameter...  Or is that part of the patch missing?

Oops, it depends on another patch: