Also fixes MDEV-32025 Crashes in MDL_key::mdl_key_init with lower-case-table-names=2
Change overview:
- In changes made in MDEV-31948, MDEV-31982 the code path
which originaly worked only in case of lower-case-table-names==1
also started to work in case of lower-case-table-names==2 in a mistake.
Restoring the original check_db_name() compatible behavior
(but without re-using check_db_name() itself).
- MDEV-31978 erroneously added a wrong DBUG_ASSERT. Removing.
Details:
- In mysql_change_db() the database name should be lower-cased only
in case of lower_case_table_names==1. It should not be lower-cased
for lower_case_table_names==2. The problem was caused by MDEV-31948.
The new code version restored the pre-MDEV-31948 behavior, which
used check_db_name() behavior.
- Passing lower_case_table_names==1 instead of just lower_case_table_names
to the "casedn" parameter to DBNameBuffer constructor in sql_parse.cc
The database name should not be lower-cased for lower_case_table_names==2.
This restores pre-MDEV-31982 behavioir which used check_db_name() here.
- Adding a new data type Lex_ident_db_normalized, it stores database
names which are both checked and normalized to lower case
in case lower_case_table_names==1 and lower_case_table_names==2.
- Changing the data type for the "db" parameter to Lex_ident_db_normalized in
lock_schema_name(), lock_db_routines(), find_db_tables_and_rm_known_files().
This is to avoid incorrectly passing a non-normalized name in the future.
- Restoring the database name normalization in mysql_create_db_internal()
and mysql_rm_db_internal() before calling lock_schema_name().
The problem was caused MDEV-31982.
- Adding database name normalization in mysql_alter_db_internal()
and mysql_upgrade_db(). This fixes MDEV-32026.
- Removing a wrong assert in Create_sp_func::create_with_db() was incorrect:
DBUG_ASSERT(Lex_ident_fs(*db).ok_for_lower_case_names());
The database name comes to here checked, but not normalized
to lower case with lower-case-table-names=2.
The assert was erroneously added by MDEV-31978.
- Recording lowercase_tables2.results and lowercase_tables4.results
according to
MDEV-29446 Change SHOW CREATE TABLE to display default collations
These tests are skipped on buildbot on all platforms, so this change
was forgotten in the patch for MDEV-29446.
