1. Store assignment failures on incompatible data types now raise errors if:
- STRICT_ALL_TABLES or STRICT_TRANS_TABLES sql_mode is used, and
- IGNORE is not used
Otherwise, only a warning is raised and the statement continues.
2. Changing the error/warning test as follows:
-ERROR HY000: Illegal parameter data types inet6 and int for operation 'SET'
+ERROR HY000: Cannot cast 'int' as 'inet6' in assignment of `db`.`t`.`col`
so in case of a big table it's easier to see which column has the problem.
The new error text is also applied to SP variables.
This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
The problem described in the bug report happened because the code
did not test check_cols(1) after fix_fields() in a few places.
Additionally, fix_fields() could be called multiple times for SP variables,
because they are all fixed at a early stage in append_for_log().
Solution:
1. Adding a few helper methods
- fix_fields_if_needed()
- fix_fields_if_needed_for_scalar()
- fix_fields_if_needed_for_bool()
- fix_fields_if_needed_for_order_by()
and using it in many cases instead of fix_fields() where
the "fixed" status is not definitely known to be "false".
2. Adding DBUG_ASSERT(!fixed) into Item_splocal*::fix_fields()
to catch double execution.
3. Adding tests.
As a good side effect, the patch removes a lot of duplicate code (~60 lines):
if (!item->fixed &&
item->fix_fields(..) &&
item->check_cols(1))
return true;