Re: Re: [BUGS] 回复： [BUGS] BUG #13762: server will crash after superuser alter function and set client_encoding

Michael Paquier <michael(dot)paquier(at)gmail(dot)com> writes:
> On Tue, Nov 10, 2015 at 9:51 AM, <funnyxj(at)qq(dot)com> wrote:
>> Sorry, the correct statements which make server crash is:
>>
>> 1. alter function koi8r_to_utf8(integer, integer, cstring, internal,
>> integer) set work_mem = '4MB';
>> 2. set client_encoding = 'koi8';
>> 3. select 1;

> This indeed crashes, and that's not limited to this particular
> function, try for example iso8859_to_utf8 with ISO_8859_6 as
> client_encoding on even a different parameter for the same result.
> FWIW, here is a backtrace with assertions enabled:

Yeah... if you trace through this, you'll notice that (1) calling a
function having non-null proconfig requires fetching its pg_proc entry,
and (2) fetching anything from a catalog requires being inside a live
transaction, and (3) the client/server encoding translation functions have
to be invokable outside any transaction. So as I said, this is not
going to work and we are not very interested in making it work.

regards, tom lane