It was wrong to derive Item_func_uuid from Item_func_sys_guid,
because the former is a function returning the UUID data type,
while the latter is a string function returning VARCHAR.
As a result of the wrong hierarchy, Item_func_uuid erroneously derived
Item_str_func::fix_fields(), which contains this code:
/*
In Item_str_func::check_well_formed_result() we may set null_value
flag on the same condition as in test() below.
*/
if (thd->is_strict_mode())
set_maybe_null();
This code is not relevant to UUID() at all.
A simple fix would be to set_maybe_null(false) in
Item_func_uuid::fix_length_and_dec(). However,
it'd fix only exactly this single consequence of the wrong
class hierarchy, and similar bugs could appear again in
the future. Moreover, we're going to add functions UUIDv4()
and UUIDv7() soon (in 11.6). So it's better to fix the class hierarchy
in the right way before adding these new functions.
Fix:
- Adding a new abstract class Item_fbt_func in the template
in sql_type_fixedbin.h
- Deriving Item_typecast_fbt from Item_fbt_func
- Deriving Item_func_uuid from Item_fbt_func
- Adding a new helper class UUIDv1. It derives from UUID, and additionally
initializes the value to "UUID version 1" right in the constructor.
Note, the new coming soon SQL functions UUIDv4() and UUIDv7()
will also have corresponding classes UUIDv4 and UUIDv7.
So now UUID() is a pure "returning UUID" function,
like CAST(expr AS UUID) used to be, without any unintentional
artifacts of functions returning VARCHAR/TEXT.
Cleanup:
- Removing the member Item_func_sys_guid::with_dashes,
as it's not needed any more:
* Item_func_sys_guid now does not have any descendants any more
* Item_func_sys_guid::val_str() itself always displays without dashes
This is a 10.2+ part of a jira task
The two bugs regarding virtual column marking have been fixed:
1. UPDATE of a partitioned table, where the optimizer has chosen a
secondary index to make a filesort;
2. INSERT into a table with a nonblob field generated from a blob, with
binlog enabled and binlog_row_image=noblob.
3. DELETE from a view on a table with virtual column.
Generally the assertion happens from update_virtual_fields() call
These bugs are root-caused by missing field marking for dependant fields
of a virtual column.
Therefore a fix is: mark all the fields involved in the vcol expression by
calling field->register_field_in_read_map() instead just setting a single
bit.
3 was reproducible only on 10.4+, however the problem might has just been
invisible in the earlier versions. The fix is applicable to 10.2-10.3 as
well.
table->move_fields wasn't undone in case of error.
1. move_fields is unconditionally undone even when error is occurred
2. cherry-pick an assertion in `ptr_in_record`, which is already in 10.5
The cause of this was several different bugs:
- When using binary logging with binlog_row_image=FULL
the all bits in read_set was set, which caused a
different (wrong) pattern for marking vcol_set.
- TABLE::mark_virtual_columns_for_write() didn't in all
cases mark vcol_set with the vcol_field.
- TABLE::update_virtual_fields() has to update all
vcol fields on REPLACE if binary logging with FULL
is used.
- VCOL_UPDATE_INDEXED should update all vcol fields part
of an index that was not updated by VCOL_UPDATE_FOR_READ
- max_row_length() calculated length of NULL and not
used fields. This didn't cause any crash, but used
more memory than needed.
