MDEV-25867 main.trigger-trans failed in bb, Assertion `ticket->m_dura…

…tion == MDL_EXPLICIT' failed in MDL_context::release_lock

release MDL on the trigger as early as possible, after everything that
cannot be done concurrently was done (under MDL), but before relocking
tables.

update C/C

Merge 10.3 to 10.4

MDEV-25886 CHECK TABLE crash with DB_MISSING_HISTORY if innodb_read_only

Occasionally, the test innodb.alter_copy would fail in MariaDB 10.6.1,
reporting DB_MISSING_HISTORY during CHECK TABLE. It started to occur during
the development of MDEV-25180, which introduced purge_sys.stop_SYS().
If we delay purge more during DDL operations, then the test would
almost always fail. The reason is that during startup we will restore
a purge view, and CHECK TABLE would still use REPEATABLE READ
even though innodb_read_only is set and other isolation levels
than READ UNCOMMITTED are not guaranteed to work.

ha_innobase::check(): Use READ UNCOMMITTED isolation level if
innodb_read_only is set or innodb_force_recovery exceeds 3.

dict_set_corrupted(): Do not update the persistent data dictionary
if innodb_force_recovery exceeds 3.

MDEV-25869 Change buffer entries are lost on InnoDB restart

buf_read_ibuf_merge_pages(): If space->size is 0, invoke
fil_space_get_size() to determine the size of the tablespace
by reading the header page. Only after that proceed to delete
any entries that are beyond the end of the tablespace.
Otherwise, we could be deleting valid entries that actually
need to be applied.

This fixes a regression that had been introduced in
commit b80df9e (MDEV-21069),
which aimed to avoid crashes during DROP TABLE of corrupted tables.

update test result

Merge branch bb-10.4-release into bb-10.5-release

remove the test for MDEV-16962

after b9d64989 the test for MDEV-16962 is not suitable anymore
(and probably the bug is not reproducible).

Fix of ppc64 by Wlad

MDEV-21603 Crashing SHOW TABLES with derived table in WHERE condition

When you only need view structure, don't call handle_derived with
DT_CREATE and rely on its internal hackish check to skip DT_CREATE.
Because handle_derived is called from many different places,
and this internal hackish check is indiscriminative.

Instead, just don't ask handle_derived to do DT_CREATE
if you don't want it to do DT_CREATE.