Odd behavior upon using Archive as default engine after plugin uninstallation

It's a meaningless test case in any practical sense, but as I've come across it accidentally, I'll leave a record of it.

install soname 'ha_archive';

set default_storage_engine = archive;

uninstall soname 'ha_archive';

create table t (a int);

show tables;

show create table t;

drop table if exists t;

install soname 'ha_archive';

set default_storage_engine = archive;

uninstall soname 'ha_archive';

Warnings:

Warning 1620    Plugin is busy and will be uninstalled on shutdown

create table t (a int);

show tables;

Tables_in_test

show create table t;

bug.t                                    [ fail ]

        Test ended at 2026-04-20 21:49:48

CURRENT_TEST: bug.t

mysqltest: At line 6: query 'show create table t' failed: ER_NO_SUCH_TABLE (1146): Table 'test.t' doesn't exist

We install the engine just to be able to set it as a default engine, then we uninstall the plugin and run CREATE TABLE. It pretends to work, but no table is actually created.

Other engines which I tried (Federated, Blackhole, RocksDB, Spider, Connect) in the same situation would still allow the table to be created – which is also a bit strange, given that engine=... specified explicitly in CREATE statement makes it throw the ER_UNKNOWN_STORAGE_ENGINE error (for all engines, including Archive), but I suppose creating a table is less wrong and can be justified by the prior "plugin is busy" warning, while pretending to create table without actually doing it can hardly be expected.