ALTER TABLE ALTER COLUMN SET TYPE crash

Hi,

Unlike a recently reported similar issue, executing the following ALTER
TABLE on the regression database crashes Postgres (master).

Admittedly it doesn't do anything constructive (and am new to the tool),
but do let me know if such reports are interesting and / or if you need
more details for reproduction.

Steps to reproduce:
==================

ubuntu(at)laptop:~$ dropdb --if-exists tempdel && createdb tempdel
ubuntu(at)laptop:~$ ./pg_regress --use-existing --schedule=serial_schedule
--dbname=tempdel >/dev/null
ubuntu(at)laptop:~$ sleep 5 && psql -c "SELECT version();" tempdel
version
--------------------------------------------------------------------------------------------------------
PostgreSQL 14devel on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu
7.5.0-3ubuntu1~18.04) 7.5.0, 64-bit
(1 row)

ubuntu(at)laptop:~$ psql -c "begin; ALTER TABLE ONLY public.xacttest ALTER
COLUMN a SET DATA TYPE TEXT USING public.max_xacttest(); ROLLBACK;"
tempdel
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
connection to server was lost
ubuntu(at)laptop:~$ sleep 5 && psql -c "SELECT 1;" tempdel
?column?
----------
1
(1 row)

-
robins tharakan