Hi Štěpán, thanks for your very detailed feedback.

>> +  (if (or keywords (and packages (listp packages)))
>                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> AKA "(consp packages)", though maybe you find your version more
> descriptive.

Thanks, didn't know they were equivalent.

>> +(defun package-menu-search (name)
>> +  "Filter the *Packages* buffer.
>> +Show only those items whose name matches NAME. If NAME is nil or an
>> +empty string, show all packages.
>
> If I was reading it as a user, I would appreciate it if the doc string
> was more specific regarding the NAME argument, e.g. said "matches the
> regular expression NAME" or something to that effect.

> Also, I think "empty string" is usually prefixed with "the", not "an",
> as there is only one such thing, e.g. (eq "" "") => t. 

I've changed the docstring as you described, I think it's clearer now.

>> +To restore the full package list, type `q'."
>> +  (interactive
>> +   (list (read-from-minibuffer "Package name: ")
>> +         current-prefix-arg))
>             ^^^^^^^^^^^^^^^^^^
>
> Is this a remnant of some previous WIP version? The function now takes a
> single argument, right?

Correct! I forgot to remove it. I was experimenting with making 'C-u s'
search packages by name, but only considering packages that were already
listed. This way it was possible to combine the keyword search and name
search. I decided against it in the end because I'm not sure if it is a
necessary addition.

I'm attaching a new patch with some changes.

- Fede