The is_infoschema_db is a deep character set based
comparision. In in many cases the db is still
an empty structure.
Doing this comparion early prevents a UBSAN error
by not performing character set operations on
a null pointer.
The patch for MDEV-31340 fixed the following bugs:
MDEV-33084 LASTVAL(t1) and LASTVAL(T1) do not work well with lower-case-table-names=0
MDEV-33085 Tables T1 and t1 do not work well with ENGINE=CSV and lower-case-table-names=0
MDEV-33086 SHOW OPEN TABLES IN DB1 -- is case insensitive with lower-case-table-names=0
MDEV-33088 Cannot create triggers in the database `MYSQL`
MDEV-33103 LOCK TABLE t1 AS t2 -- alias is not case sensitive with lower-case-table-names=0
MDEV-33108 TABLE_STATISTICS and INDEX_STATISTICS are case insensitive with lower-case-table-names=0
MDEV-33109 DROP DATABASE MYSQL -- does not drop SP with lower-case-table-names=0
MDEV-33110 HANDLER commands are case insensitive with lower-case-table-names=0
MDEV-33119 User is case insensitive in INFORMATION_SCHEMA.VIEWS
MDEV-33120 System log table names are case insensitive with lower-cast-table-names=0
Backporting the fixes from 11.5 to 10.5
This patch also fixes:
MDEV-33050 Build-in schemas like oracle_schema are accent insensitive
MDEV-33084 LASTVAL(t1) and LASTVAL(T1) do not work well with lower-case-table-names=0
MDEV-33085 Tables T1 and t1 do not work well with ENGINE=CSV and lower-case-table-names=0
MDEV-33086 SHOW OPEN TABLES IN DB1 -- is case insensitive with lower-case-table-names=0
MDEV-33088 Cannot create triggers in the database `MYSQL`
MDEV-33103 LOCK TABLE t1 AS t2 -- alias is not case sensitive with lower-case-table-names=0
MDEV-33109 DROP DATABASE MYSQL -- does not drop SP with lower-case-table-names=0
MDEV-33110 HANDLER commands are case insensitive with lower-case-table-names=0
MDEV-33119 User is case insensitive in INFORMATION_SCHEMA.VIEWS
MDEV-33120 System log table names are case insensitive with lower-cast-table-names=0
- Removing the virtual function strnncoll() from MY_COLLATION_HANDLER
- Adding a wrapper function CHARSET_INFO::streq(), to compare
two strings for equality. For now it calls strnncoll() internally.
In the future it will turn into a virtual function.
- Adding new accent sensitive case insensitive collations:
- utf8mb4_general1400_as_ci
- utf8mb3_general1400_as_ci
They implement accent sensitive case insensitive comparison.
The weight of a character is equal to the code point of its
upper case variant. These collations use Unicode-14.0.0 casefolding data.
The result of
my_charset_utf8mb3_general1400_as_ci.strcoll()
is very close to the former
my_charset_utf8mb3_general_ci.strcasecmp()
There is only a difference in a couple dozen rare characters, because:
- the switch from "tolower" to "toupper" comparison, to make
utf8mb3_general1400_as_ci closer to utf8mb3_general_ci
- the switch from Unicode-3.0.0 to Unicode-14.0.0
This difference should be tolarable. See the list of affected
characters in the MDEV description.
Note, utf8mb4_general1400_as_ci correctly handles non-BMP characters!
Unlike utf8mb4_general_ci, it does not treat all BMP characters
as equal.
- Adding classes representing names of the file based database objects:
Lex_ident_db
Lex_ident_table
Lex_ident_trigger
Their comparison collation depends on the underlying
file system case sensitivity and on --lower-case-table-names
and can be either my_charset_bin or my_charset_utf8mb3_general1400_as_ci.
- Adding classes representing names of other database objects,
whose names have case insensitive comparison style,
using my_charset_utf8mb3_general1400_as_ci:
Lex_ident_column
Lex_ident_sys_var
Lex_ident_user_var
Lex_ident_sp_var
Lex_ident_ps
Lex_ident_i_s_table
Lex_ident_window
Lex_ident_func
Lex_ident_partition
Lex_ident_with_element
Lex_ident_rpl_filter
Lex_ident_master_info
Lex_ident_host
Lex_ident_locale
Lex_ident_plugin
Lex_ident_engine
Lex_ident_server
Lex_ident_savepoint
Lex_ident_charset
engine_option_value::Name
- All the mentioned Lex_ident_xxx classes implement a method streq():
if (ident1.streq(ident2))
do_equal();
This method works as a wrapper for CHARSET_INFO::streq().
- Changing a lot of "LEX_CSTRING name" to "Lex_ident_xxx name"
in class members and in function/method parameters.
- Replacing all calls like
system_charset_info->coll->strcasecmp(ident1, ident2)
to
ident1.streq(ident2)
- Taking advantage of the c++11 user defined literal operator
for LEX_CSTRING (see m_strings.h) and Lex_ident_xxx (see lex_ident.h)
data types. Use example:
const Lex_ident_column primary_key_name= "PRIMARY"_Lex_ident_column;
is now a shorter version of:
const Lex_ident_column primary_key_name=
Lex_ident_column({STRING_WITH_LEN("PRIMARY")});
Under terms of MDEV 27490 we'll add support for non-BMP identifiers
and upgrade casefolding information to Unicode version 14.0.0.
In Unicode-14.0.0 conversion to lower and upper cases can increase octet length
of the string, so conversion won't be possible in-place any more.
This patch removes virtual functions performing in-place casefolding:
- my_charset_handler_st::casedn_str()
- my_charset_handler_st::caseup_str()
and fixes the code to use the non-inplace functions instead:
- my_charset_handler_st::casedn()
- my_charset_handler_st::caseup()
Problem:
Under terms of MDEV-27490, we'll update Unicode version used
to compare identifiers to 14.0.0. Unlike in the old Unicode version,
in the new version a string can grow during lower-case. We cannot
perform check_db_name() inplace any more.
Change summary:
- Allocate memory to store lower-cased identifiers in memory root
- Removing check_db_name() performing both in-place lower-casing and validation
at the same time. Splitting it into two separate stages:
* creating a memory-root lower-cased copy of an identifier
(using new MEM_ROOT functions and Query_arena wrapper methods)
* performing validation on a constant string
(using Lex_ident_fs methods)
Implementation details:
- Adding a mysys helper function to allocate lower-cased strings on MEM_ROOT:
lex_string_casedn_root()
and a Query_arena wrappers for it:
make_ident_casedn()
make_ident_opt_casedn()
- Adding a Query_arena method to perform both MEM_ROOT lower-casing and
database name validation at the same time:
to_ident_db_internal_with_error()
This method is very close to the old (pre-11.3) check_db_name(),
but performs lower-casing to a newly allocated MEM_ROOT
memory (instead of performing lower-casing the original string in-place).
- Adding a Table_ident method which additionally handles derived table names:
to_ident_db_internal_with_error()
- Removing the old check_db_name()
Also fixes MDEV-32025 Crashes in MDL_key::mdl_key_init with lower-case-table-names=2
Change overview:
- In changes made in MDEV-31948, MDEV-31982 the code path
which originaly worked only in case of lower-case-table-names==1
also started to work in case of lower-case-table-names==2 in a mistake.
Restoring the original check_db_name() compatible behavior
(but without re-using check_db_name() itself).
- MDEV-31978 erroneously added a wrong DBUG_ASSERT. Removing.
Details:
- In mysql_change_db() the database name should be lower-cased only
in case of lower_case_table_names==1. It should not be lower-cased
for lower_case_table_names==2. The problem was caused by MDEV-31948.
The new code version restored the pre-MDEV-31948 behavior, which
used check_db_name() behavior.
- Passing lower_case_table_names==1 instead of just lower_case_table_names
to the "casedn" parameter to DBNameBuffer constructor in sql_parse.cc
The database name should not be lower-cased for lower_case_table_names==2.
This restores pre-MDEV-31982 behavioir which used check_db_name() here.
- Adding a new data type Lex_ident_db_normalized, it stores database
names which are both checked and normalized to lower case
in case lower_case_table_names==1 and lower_case_table_names==2.
- Changing the data type for the "db" parameter to Lex_ident_db_normalized in
lock_schema_name(), lock_db_routines(), find_db_tables_and_rm_known_files().
This is to avoid incorrectly passing a non-normalized name in the future.
- Restoring the database name normalization in mysql_create_db_internal()
and mysql_rm_db_internal() before calling lock_schema_name().
The problem was caused MDEV-31982.
- Adding database name normalization in mysql_alter_db_internal()
and mysql_upgrade_db(). This fixes MDEV-32026.
- Removing a wrong assert in Create_sp_func::create_with_db() was incorrect:
DBUG_ASSERT(Lex_ident_fs(*db).ok_for_lower_case_names());
The database name comes to here checked, but not normalized
to lower case with lower-case-table-names=2.
The assert was erroneously added by MDEV-31978.
- Recording lowercase_tables2.results and lowercase_tables4.results
according to
MDEV-29446 Change SHOW CREATE TABLE to display default collations
These tests are skipped on buildbot on all platforms, so this change
was forgotten in the patch for MDEV-29446.
Replacing my_casedn_str() called on local char[] buffer variables
to CharBuffer::copy_casedn() calls.
This is a sub-task for MDEV-31531 Remove my_casedn_str()
Details:
- Adding a helper template class IdentBuffer (a CharBuffer descendant),
which assumes utf8 data. Like CharBuffer, it's initialized to an empty
string in the constructor, but can be populated with lower-cased data
later.
- Adding a helper template class IdentBufferCasedn, which initializes
to lower case right in the constructor.
- Removing char[] buffers, replacing them to IdentBuffer and IdentBufferCasedn.
- Changing the data type of "db" and "table" parameters from
"const char*" to LEX_CSTRING in the following functions:
find_field_in_table_ref()
insert_fields()
set_thd_db()
mysql_grant()
to reuse IdentBuffer easeir.
- Replacing the old style inplace check_db_name() in make_table_name_list()
to the new style non-modifying code
- Adding "const" qualifier to the "db" parameter to ha_discover_table_names()
and its dependency functions.
- Adding a new class Lex_ident_db, to store normalized database names:
lower-cased if lower-case-table-name says so,
and checked to be a valid database name using Lex_ident_fs::check_db_name()
- Reusing the new class in parameters to functions:
prepare_db_action()
mysql_create_db()
mysql_alter_db()
mysql_rm_db()
mysql_upgrade_db()
This change removed two old-style check_db_name() calls.
- Changing the global function ok_for_lower_case_names()
into a method in class Lex_ident_fs.
- Changing a few functions/methods to get the database name
as a "const LEX_CSTRING" instead of a "const char *".
All these functions/methods use ok_for_lower_case_names()
inside. This change helps to avoid new strlen() calls, and also
removes a few old strlen() calls.
- Adding a class Lex_ident_fs, to store identifiers for on-disk
database objects, such as databases, tables, triggers.
- Moving the validation code from check_db_name()
to non-modifying methods in Lex_ident_fs:
Lex_ident_fs::check_body()
Lex_ident_fs::check_db_name()
Adding a new method Lex_ident_fs::check_db_name_with_error(),
which performs validation and raises an error on validation failure.
Unlike the old function check_db_name(), the new class Lex_ident_fs
does not lower-case the identifier during the validation.
Lower-casing must be done before calling Lex_ident_fs validation methods.
- Adding a low level helper template class CharBuffer which can:
* store exact or lower-cased strings with a short fixed maximum length
* return the value as a LEX_CSTRING efficiently
- Adding a helper template class DBNameBuffer (deriving from CharBuffer), to
allocate optionally lower-cased database identifiers on stack when relevant.
Useful for temporary values which don't need to be allocated on MEM_ROOT.
- Using DBNameBuffer in mysql_change_db()
- Using DBNameBuffer in show_create_db()
