ER_PROCACCESS_DENIED_ERROR loses SP name when SET PATH points at a wrong location, UBSAN errors in char_buffer.h

CREATE USER u;

CREATE DATABASE db;

GRANT SELECT ON db.* TO u;

CREATE FUNCTION db.f() RETURNS INT RETURN 1;

--connect (con1,localhost,u,,)

--error ER_PROCACCESS_DENIED_ERROR

SELECT db.f();

--error ER_PROCACCESS_DENIED_ERROR

SELECT xx.f();

SET PATH 'db';

--error ER_PROCACCESS_DENIED_ERROR

SELECT f();

SET PATH 'xx';

--error ER_PROCACCESS_DENIED_ERROR

SELECT f();

--disconnect con1

--connection default

DROP DATABASE db;

DROP USER u;

SELECT db.f();

ERROR 42000: execute command denied to user 'u'@'%' for routine 'db.f'

SELECT xx.f();

ERROR 42000: execute command denied to user 'u'@'%' for routine 'xx.f'

SET PATH 'db';

SELECT f();

ERROR 42000: execute command denied to user 'u'@'%' for routine 'db.f'

SET PATH 'xx';

SELECT f();

ERROR 42000: execute command denied to user 'u'@'%' for routine ''

/data/bld/12.3-asan-ubsan/sql/char_buffer.h:113:11: runtime error: null pointer passed as argument 2, which is declared to never be null