INSERT IGNORE had a pecular undocumented case that when one row was
inserted, there was an error rather than a warning.
As LOAD DATA IGNORE, UPDATE IGNORE, INSERT IGNORE SELECT, and INSERT
IGNORE VALUES (single row, for foreign key violation) all behave the same
way with a warning lets keep the behaviour normalized.
In compatibility, previously a error was generated, now a warning is
generated.
This behaviour is now consistent with MySQL-8.0 too.
remove the hack where NO_DEFAULT_VALUE_FLAG was temporarily removed
from a field to initialize DEFAULT() functions in CHECK constraints
while disabling self-reference field checks.
Instead, initialize DEFAULT() functions in CHECK explicitly,
don't call check_field_expression_processor() for CHECK at all.
This patch adds for "--ps-protocol" second execution
of queries "SELECT".
Also in this patch it is added ability to disable/enable
(--disable_ps2_protocol/--enable_ps2_protocol) second
execution for "--ps-prototocol" in testcases.
partially revert 76063c2a13. Item::clone() is not an all-purpose
Item copying machine, it was specifically created for pushdown
of predicates into derived tables and views and it does not
copy everything. In particular, it does not copy Item_func_regex.
Fix the bug differently by preserving the old constraint name.
But keep setting automatic_name=true to have it regenerated
for cases like ALTER TABLE ... ADD CONSTRAINT.
