Re: ProcessStartupPacket(): database_name and user_name truncation

Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> writes:
> At Wed, 21 Jun 2023 09:43:50 +0200, "Drouvot, Bertrand" <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote in
>> Trying to connect with the 64 bytes name:
>> $ psql -d ääääääääääääääääääääääääääääääää
>> psql: error: connection to server on socket "/tmp/.s.PGSQL.55448"
>> failed: FATAL: database "äääääääääääääääääääääääääääääää" does not
>> exist

> IMHO, I'm not sure we should allow connections without the exact name
> being provided. In that sense, I think we might want to consider
> outright rejecting the estblishment of a connection when the given
> database name doesn't fit the startup packet, since the database with
> the exact given name cannot be found.

I think I agree. I don't like the proposed patch at all, because it's
making completely unsupportable assumptions about what encoding the
names are given in. Simply failing to match when a name is overlength
sounds safer.

(Our whole story about what is the encoding of names in shared catalogs
is a mess. But this particular point doesn't seem like the place to
start if you want to clean that up.)

regards, tom lane