Re: proposal psql \gdesc

Hello Pavel,

> I am sending a variant with message instead empty result.

Thanks. Patch looks good, applies, make check ok, code is neat.

> Personally I prefer empty result instead message.

Hmm. I think that this version is less likely to raise questions from
users, especially compared to having a somehow correct but strangely
looking description.

> It is hard to choose some good text of this message. Empty result is
> just empty result for all cases.

I'd suggest a very minor change: "No columns or command has no result"
(not -> no). If some English native speaker has a better suggestion,
fine with me.

Another good point of this version is that the type name query is
simplified because it does not need to handle an empty result, thus the
code is easier to understand.

A few other suggestions:

- could you update the comment on the type name query?
Maybe the comment can be simply removed?

- I'm wondering whether the Name & Type columns names should be
translatable. What do you think?

- Maybe tests could also exercise unnamed columns, eg:
SELECT 1, 2, 3 \gdesc \g

--
Fabien.