bug#39436: 27.0.60; Documentaion error for package-menu-hide-package

[Eli Zaretskii]

> From: Pieter van Oostrum <pieter-l@vanoostrum.org>
> Cc: eliz@gnu.org,  pieter@vanoostrum.org
> Date: Sat, 08 Feb 2020 14:58:27 +0100
> 
> This part isn't correct.
> 
> The default value of the
> regexp will hide only the package whose name is at point, so just
> pressing @key{RET} to the prompt will hide the current package.
> 
> It will hide every package whose name STARTS WITH the name of the
> current package

Which is a bug in the code, not in the documentation, IMO.  It makes
no sense to show as default a regexp that will hide more than just the
package at point.

This is why I said in the documentation what I think should happen,
although I did see the regexp we offer as the default.  Patches to
make the code do what it should are welcome.