In case of direct execution(stmtid=-1, mariadb_stmt_execute_direct in C
API) application is in control of how many parameters client sends to
the server. In case this number is not equal to actual query parameters
number, the server may start to interprete packet data incorrectly, e.g.
starting from the size of null bitmap. And that could cause it to crash
at some point. The commit introduces some additional COM_STMT_EXECUTE
packet sanity checks:
- checking that "types sent" byte is set, and the value is equal to 1.
if it's not direct execution, then that value is 0 or 1.
- checking that parameter type value is a valid type, and parameter
flags value is 0 or only "unsigned" bit is set
- added more checks that read does not go beyond the end of the packet
For some reason, adding -fsanitize=undefined (cmake -DWITH_UBSAN=ON)
to the compilation flags will cause even more warnings to be emitted.
The warning was a bogus one:
tests/mysql_client_test.c:8632:22: error: '%d' directive writing between
1 and 11 bytes into a region of size 9 [-Werror=format-overflow=]
8632 | sprintf(field, "c%d int", i);
| ^~
tests/mysql_client_test.c:8632:20: note: directive argument
in the range [-2147483648, 999]
The warning does not take into account that the lower bound of the
variable actually is 0. But, we can help the compiler and use an
unsigned variable.
The COM_MULTI did not take off. No connector is using it.
Remove related code from server, and client.
If anything it is a step simplification of already-bloated
dispatch_command(), and related code.
When a prepared statement parameter '?' is used in a CTE that is used
multiple times, the following happens:
- The CTE definition is re-parsed multiple times.
- There are multiple Item_param objects referring to the same "?" in
the original query.
- Prepared_statement::param has a pointer to the first of them, the
others are "clones".
- When prepared statement parameter gets the value, it should be passed
over to clones with param->sync_clones() call.
This call is made in insert_params(), etc. It was not made in
insert_params_with_log().
This would cause Item_param to not have any value which would confuse
the query optimizer.
Added the missing call.
Type_handler_xxx::Item_const_eq() can handle only non-NULL values.
The code in Item_basic_value::eq() did not take this into account.
Adding a test to detect three different combinations:
- Both values are NULLs, return true.
- Only one value is NULL, return false.
- Both values are not NULL, call Type_handler::Item_const_eq()
to check equality.
- --default-character-set can now be disabled in mysqldump
- --skip-resolve can be be disabled in mysqld
- mysql_client_test now resets global variables it changes
- mtr couldn't handle [mysqldump] in config files (wrong regexp used)
The bug was that when using mysql_list_fields, then
table_list->schema_table_name was not filled in.
Fixed by using table_list->schema_table instead, which is always
filled in.
The problem happened because Item_ident_for_show did not implement val_native().
Solution:
- Removing class Item_ident_for_show
- Implementing a new method Protocol::send_list_fields() instead,
which accepts a List<Field> instead of List<Item> as input.
Now no any Item creation is done during mysqld_list_fields().
Adding helper methods, to reuse the code easier:
- Moved a part of Protocol::send_result_set_metadata(),
responsible for sending an individual field metadata,
into a new method Protocol_text::store_field_metadata().
Reusing it in both send_list_fields() and send_result_set_metadata().
- Adding Protocol_text::store_field_metadata()
- Adding Protocol_text::store_field_metadata_for_list_fields()
Note, this patch also automatically fixed another bug:
MDEV-18685 mysql_list_fields() returns DEFAULT 0 instead of DEFAULT NULL for view columns
The reason for this bug was that Item_ident_for_show::val_xxx() and get_date()
did not check field->is_null() before calling field->val_xxx()/get_date().
Now the default value is correctly sent by Protocol_text::store(Field*).
This patch contains a full implementation of the optimization
that allows to use in-memory rowid / primary filters built for range
conditions over indexes. In many cases usage of such filters reduce
the number of disk seeks spent for fetching table rows.
In this implementation the choice of what possible filter to be applied
(if any) is made purely on cost-based considerations.
This implementation re-achitectured the partial implementation of
the feature pushed by Galina Shalygina in the commit
8d5a11122c.
Besides this patch contains a better implementation of the generic
handler function handler::multi_range_read_info_const() that
takes into account gaps between ranges when calculating the cost of
range index scans. It also contains some corrections of the
implementation of the handler function records_in_range() for MyISAM.
This patch supports the feature for InnoDB and MyISAM.
- Removed test if HA_FT_WTYPE == HA_KEYTYPE_FLOAT as this never worked
(HA_KEYTYPE_FLOAT is an enum)
- Define HA_FT_MAXLEN to 126 (was tested before but never defined)
