FOREIGN_KEY_CHECKS is disabled
- Referenced index can be null While renaming the referenced column name.
In that case, rename the referenced column name in dict_foreign_t and
find the equivalent referenced index.
FOREIGN_KEY_CHECKS is disabled
- dict_foreign_find_index() can return NULL if InnoDB already dropped
the foreign index when FOREIGN_KEY_CHECKS is disabled.
dict_create_foreign_constraints_low(): Tolerate the keywords
IGNORE and ONLINE between the keywords ALTER and TABLE.
We should really remove the hacky FOREIGN KEY constraint parser
from InnoDB.
dict_create_foreign_constraints_low(): Clean up the way in
which the error messages are initialized, and ensure that
the table name is always initialized.
The code path where the table was not being rebuilt during ALTER TABLE
was not covered by the test. Add coverage, and remove the debug assertion
that could fail in this case.
ha_innobase::commit_inplace_alter_table(): Do not crash if
innobase_update_foreign_cache() returns an error. It can return
an error on ALTER TABLE if an inconsistent FOREIGN KEY constraint
was created earlier when SET foreign_key_checks=0 was in effect.
Instead, report a warning to the client that constraints cannot
be loaded.
In RENAME TABLE, when an error occurs while renaming FOREIGN KEY
constraint, that error would be overwritten when renaming the
InnoDB internal tables related to FULLTEXT INDEX.
row_rename_table_for_mysql(): Do not attempt to rename the internal
tables if an error already occurred.
This problem was originally reported as Oracle Bug#27545888.
table_already_fk_prelocked() was looking for a table in the wrong
list (not the complete list of prelocked tables, but only in its tail,
starting from the current table - which is always empty for the last
added table), so for circular FKs it kept adding same tables to the list
indefinitely.
Backport of d6d7e169fb
