This is a 10.3 specific part of MDEV-13049.
It disables automatic sorting for
"SELECT .. FROM INFORMATION_SCHEMA.{SCHEMATA|TABLES}"
and adjusts the affected tests accordingly.
- Implementing stricter data type control for Item_long_func descendants
- Cleanup: renaming Type_handler::can_return_str_ascii() to can_return_text()
(a better name).
The bug happens because of a combination of unfortunate circumstances:
1. Arguments args[0] and args[2] of Item_func_concat point recursively
(through Item_direct_view_ref's) to the same Item_func_conv_charset.
Both args[0]->args[0]->ref[0] and args[2]->args[0]->ref[0] refer to
this Item_func_conv_charset.
2. When Item_func_concat::args[0]->val_str() is called,
Item_func_conv_charset::val_str() writes its result to
Item_func_conc_charset::tmp_value.
3. Then, for optimization purposes (to avoid copying),
Item_func_substr::val_str() initializes Item_func_substr::tmp_value
to point to the buffer fragment owned by Item_func_conv_charset::tmp_value
Item_func_substr::tmp_value is returned as a result of
Item_func_concat::args[0]->val_str().
4. Due to optimization to avoid memory reallocs,
Item_func_concat::val_str() remembers the result of args[0]->val_str()
in "res" and further uses "res" to collect the return value.
5. When Item_func_concat::args[2]->val_str() is called,
Item_func_conv_charset::tmp_value gets overwritten (see #1),
which effectively overwrites args[0]'s Item_func_substr::tmp_value (see #3),
which effectively overwrites "res" (see #4).
This patch does the following:
a. Changes Item_func_conv_charset::val_str(String *str) to use
tmp_value and str the other way around. After this change tmp_value
is used to store a temporary result, while str is used to return the value.
The fixes the second problem (without SUBSTR):
SELECT CONCAT(t2,'-',t2) c2
FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
As Item_func_concat::val_str() supplies two different buffers when calling
args[0]->val_str() and args[2]->val_str(), in the new reduction the result
created during args[0]->val_str() does not get overwritten by
args[2]->val_str().
b. Fixing the same problem in val_str() for similar classes
Item_func_to_base64
Item_func_from_base64
Item_func_weight_string
Item_func_hex
Item_func_unhex
Item_func_quote
Item_func_compress
Item_func_uncompress
Item_func_des_encrypt
Item_func_des_decrypt
Item_func_conv_charset
Item_func_reverse
Item_func_soundex
Item_func_aes_encrypt
Item_func_aes_decrypt
Item_func_buffer
c. Fixing Item_func::val_str_from_val_str_ascii() the same way.
Now Item_str_ascii_func::ascii_buff is used for temporary value,
while the parameter passed to val_str() is used to return the result.
This fixes the same problem when conversion (from ASCII to e.g. UCS2)
takes place. See the ctype_ucs.test for example queries that returned
wrong results before the fix.
d. Some Item_func descendand classes had temporary String buffers
(tmp_value and tmp_str), but did not really use them.
Removing these temporary buffers from:
Item_func_decode_histogram
Item_func_format
Item_func_binlog_gtid_pos
Item_func_spatial_collection:
e. Removing Item_func_buffer::tmp_value, because it's not used any more.
f. Renaming Item_func_[un]compress::buffer to "tmp_value",
for consistency with other classes.
Note, this patch does not fix the following classes
(although they have a similar problem):
Item_str_conv
Item_func_make_set
Item_char_typecast
They have a complex implementations and simple swapping between "tmp_value"
and "str" won't work. These classes will be fixed separately.
This is a join patch fixing these two bugs:
MDEV-12560 Wrong data type for SELECT NULL UNION SELECT Point(1,1)
MDEV-12665 Hybrid functions do not preserve geometry type
This patch does the following:
1. Adds a new method Type_handler_hybrid_field_type::aggregate_for_min_max()
- For non-traditional data types it uses
type_handler_data->m_type_aggregator_for_result.find_handler()
This allows pluggable data types to define in the future their
own behavior of the result data type detection for LEAST/GREATEST.
Also, this disallows expressions of the GEOMETRY data type
(and its variants such as POINT) to be mixed in with
numeric and temporal data types in LEAST/GREATEST.
- For traditional data types it reproduces the old behavior of
the result data type detection (but not attributes, see below).
2. Adds a new virtual method Type_handler::Item_func_min_max_fix_attributes()
and reuses as much as possible the code that calculates data type attributes
for CASE-alike functions (e.g. CASE..THEN, COALESCE, IF).
As the old code responsible for attributes calculation in the old
implementation of Item_func_min_max::fix_length_and_dec()
was not fully correct, this automatically fixes the following bugs:
- MDEV-12497 Wrong data type for LEAST(latin1_expr, utf8_expr)
The old fix_length_and_dec() calculated max_length before
character set aggregation. Now max_length is calculated after, in
Item_func::count_string_length() called from
Item_func::aggregate_attributes_string() called from
Type_handler_string_result::Item_hybrid_func_fix_attributes() called from
Type_handler::Item_func_min_max_fix_attributes() called from
Item_func_min_max::fix_length_and_dec().
- MDEV-12504 Wrong data type for LEAST(date_expr,time_expr)
The old fix_length_and_dec() simply used the maximum of max_length
among all arguments to set its own max_length and did not take
into account that a mixture of DATE and TIME becomes DATETIME.
Now this is correctly handled by:
Type_handler_datetime_common::Item_hybrid_func_fix_attributes() called from
Type_handler::Item_func_min_max_fix_attributes() called from
Item_func_min_max::fix_length_and_dec().
3. Removes the old implementation of Item_func_min_max::fix_length_and_dec()
and replaces it to calls of the new methods.
4. Cleanup: moves the code related to unsigned_flag processing
from Type_handler_hybrid_field_type::aggregate_for_result()
to Type_handler_int_result::Item_hybrid_func_fix_attributes().
This is done:
- to avoid code duplication in
Type_handler_hybrid_field_type::aggregate_for_min_max()
- to get rid of one more call for field_type(), which is unfriendly
to the conceipt of pluggable data types.
This patch implements MDEV-12514 according to the task descriptions.
It automatically fixes:
MDEV-12515 Wrong value when storing DATE_ADD() and ADDTIME() to a numeric field
Additionally:
a. Moves Item_func::set_attributes_temporal() to
Type_str_attributes::fix_attributes_temporal(),
which is a more proper place and name for it.
b. Continues replacing calls for:
set_handler_by_field_type(MYSQL_TYPE_XXX)
to corresponding:
set_handler(&type_handler_xxx)
which is faster.
Note, we should eventually get rid of almost all set_handler_by_field_type().
c. Makes type_handler_string, type_handler_time2, type_handler_newdate,
type_handler_datetime2 public.
(all built-in handlers will become public eventually)
d. Removing Item_temporal_func::sql_mode, as it was not used.
Make SELECT <columns> FROM I_S.TABLES behave identically independently
from whether <columns> require opening the table in engine or
<columns> can be filled with only opening the frm.
In particular, fill_schema_table_from_frm() should not silently skip
frms with unknown engine, but should fill the I_S.TABLES row
with NULLs just like fill_schema_table_by_open() does.
This patch makes the following changes (according to the task description):
- Adds Type_handler::Item_func_round_fix_length_and_dec().
- Splits the code from Item_func_round::fix_length_and_dec() into new
Item_func_round methods fix_arg_int(), fix_arg_decimal(), fix_arg_double().
- Calls the new Item_func_round methods from the relevant implementations of
Type_handler_xxx::Item_func_round_fix_length_and_dec().
- Adds a new error message ER_ILLEGAL_PARAMETER_DATA_TYPE_FOR_OPERATION
- Makes ROUND() return the new error for GEOMETRY
Additionally:
- Inherits Item_func_round directly from Item_func_numhybrid as it
uses nothing from Item_func_num1.
- Fixes "MDEV-12000 ROUND(expr,const_expr_returning_NULL) creates DOUBLE(0,0)".
Now if args[1] returns NULL, the data type is set to DOUBLE with
NOT_FIXED_DEC decimals instead of 0 decimals.
- Adding SHOW CREATE TABLE into all DEFAULT tests,
to cover need_parentheses_in_default() for all items
- Fixing a few items not to print parentheses in DEFAULT:
spatial function-alike predicates, IS_IPV4 and IS_IPV6 functions,
COLUMN_CHECK() and COLUMN_EXISTS().
Problem was that we considered the point itself as the 'border' object. Instead
of that the 'border' of a POINT is an empty set, and the point is the 'interior'.
Another error fixed by the way - not all operations of the resulting function were properly
allocated.
- Renaming Item::is_bool_func() to is_bool_type(), to avoid assumption
that the item is an Item_func derivant.
- Deriving Item_func_spatial_rel from Item_bool_func rather than Item_int_func
