bug#64902: 30.0.50; REQUIRE-MATCH completing-read arg in describe-* commands

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

> I still don't understand why you insist to have confirmation from user,

Hmm... maybe you're right and we don't need the confirmation.

>> This way `describe-function` could distinguish between names which are
>> sure to correspond to nothing (e.g. there is no matching symbol in
>> `obarray`, or there is but it has both `symbol-function` and
>> `symbol-plist` are empty) and names where `symbol-function` is nil, but
>> there are some properties defined.
>
> Not sure to understand what the predicate would be:
>
> (and (symbol-function sym) (symbol-plist sym))

No.

> (or (symbol-function sym) (symbol-plist sym))

Yes.

> In the example shown in screenshot I sent before I used symbol-function
> alone, isn't it enough?

Having tried now I see that the command signals an error when
symbol-function is void.  Apparently this use-case is not tested enough
to keep it working, so I've changed my mind: I just reverted
my change.

Thanks for bringing it up :-)


        Stefan