Re: psql: Fix CREATE SCHEMA scanning of nested routine bodies

> On Jun 23, 2026, at 00:04, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> writes:
>> See this repro:
>> ```
>> evantest=# CREATE SCHEMA s CREATE VIEW begin AS SELECT 1;
>> evantest-# end;
>> WARNING: there is no transaction in progress
>> CREATE SCHEMA
>> COMMIT
>> ```
>
> Meh. Yeah, you can fool psql by using non-reserved keywords as
> identifiers. I'm not super excited about adding complexity that
> resolves specific edge cases of that kind, because there will always
> be more of them. As an example, this fools both HEAD and the back
> branches:
>
> regression=# create function begin() returns int
> regression-# begin atomic return 2+2; end;
> regression-#
>
> Is it really likely that anyone will use "begin" as an object name?
>
> Having said that, I agree that what psqlscan.l is doing now is quite
> hokey and maybe we should make it smarter. I don't like the details
> of your patch too much though. It's too obviously bolted on: the
> added parsing logic looks nothing like what was there before.
> Also, I think it can still be fooled by
>
> create schema s
> create function f() ... as $$ function body $$
> create view begin as ...
>
> because you don't reset create_schema_routine_body unless you
> see "end".
>
> What I'd think about doing, if you want to pursue this, is to
> have a buffer similar to cur_state->identifiers[] but it tracks
> identifiers starting from the most recent CREATE sub-clause
> start within CREATE SCHEMA (ie, a non-nested CREATE keyword),
> and then applies basically the same logic as in the original code
> to decide if we're within a CREATE FUNCTION sub-clause.
>
> Also, you could avoid cluttering other productions by resetting
> all the new state when identifier_count is zero, in the same place
> where we reset cur_state->identifiers[] today.
>
> It'd likely be appropriate to pull all this logic out of the
> {identifier} production and put it in a subroutine, just because
> it's getting unduly complicated.
>
> regards, tom lane

Thanks for the detailed explanation. I will try to rework the patch along the direction you suggested.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/