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@laptop:~$ dropdb --if-exists tempdel && createdb tempdel
ubuntu@laptop:~$ ./pg_regress --use-existing --schedule=serial_schedule --dbname=tempdel >/dev/null
ubuntu@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@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@laptop:~$ sleep 5 && psql -c "SELECT 1;" tempdel
 ?column?
----------
        1
(1 row)

-
robins tharakan