This is a refactoring patch, it does not change the behaviour.
The MTR tests are being added only to cover the LIKE predicate better.
(these tests should have been added earlier under terms of MDEV 9711).
This patch does not need its own specific MTR tests.
Moving the duplicate code into a new shared file ctype-wildcmp.inl
and including it from multiple places, to define the following functions:
- my_wildcmp_uca_impl(), in ctype-uca.c
For utf8mb3, utf8mb4, ucs2, utf16, utf32, using cs->cset->mb_wc().
For UCA based collations.
- my_wildcmp_mb2_or_mb4_general_ci_impl(), in ctype-ucs2.c:
For ucs2, utf16, utf32, using cs->cset->mb_wc().
For general_ci-style collations:
- xxx_general_ci
- xxx_general_mysql500_ci
- xxx_general_nopad_ci
- my_wildcmp_mb2_or_mb4_bin_impl(), in ctype-ucs2.c:
For ucs2, utf16, utf32, using cs->cset->mb_wc().
For _bin collations:
- xxx_bin
- xxx_nopad_bin
- my_wildcmp_utf8mb3_general_ci_impl(), in ctype-utf8.c
Optimized for utf8mb3, using my_mb_wc_utf8mb3_quick().
For general_ci-style collations:
- utf8mb3_general_ci
- utf8mb3_general_mysql500_ci
- utf8mb3_general_nopad_ci
- my_wildcmp_utf8mb4_general_ci_impl(), in ctype-utf8.c
Optimized for utf8mb4, using my_mb_wc_utf8mb4_quick().
For general_ci-style collations:
- utf8mb4_general_ci
- utf8mb4_general_nopad_ci
This is a non-functional change. It changes the way how case folding data
and weight data (for simple Unicode collations) are stored:
- Removing data types MY_UNICASE_CHARACTER, MY_UNICASE_INFO
- Using data types MY_CASEFOLD_CHARACTER, MY_CASEFOLD_INFO instead.
This patch changes simple Unicode collations in a similar way
how MDEV-30695 previously changed Asian collations.
No new MTR tests are needed. The underlying code is thoroughly
covered by a number of ctype_*_ws.test and ctype_*_casefold.test
files, which were added recently as a preparation
for this change.
Old and new Unicode data layout
-------------------------------
Case folding data is now stored in separate tables
consisting of MY_CASEFOLD_CHARACTER elements with two members:
typedef struct casefold_info_char_t
{
uint32 toupper;
uint32 tolower;
} MY_CASEFOLD_CHARACTER;
while weight data (for simple non-UCA collations xxx_general_ci
and xxx_general_mysql500_ci) is stored in separate arrays of
uint16 elements.
Before this change case folding data and simple weight data were
stored together, in tables of the following elements with three members:
typedef struct unicase_info_char_st
{
uint32 toupper;
uint32 tolower;
uint32 sort; /* weights for simple collations */
} MY_UNICASE_CHARACTER;
This data format was redundant, because weights (the "sort" member) were
needed only for these two simple Unicode collations:
- xxx_general_ci
- xxx_general_mysql500_ci
Adding case folding information for Unicode-14.0.0 using the old
format would waste memory without purpose.
Detailed changes
----------------
- Changing the underlying data types as described above
- Including unidata-dump.c into the sources.
This program was earlier used to dump UnicodeData.txt
(e.g. https://www.unicode.org/Public/14.0.0/ucd/UnicodeData.txt)
into MySQL / MariaDB source files.
It was originally written in 2002, but has not been distributed yet
together with MySQL / MariaDB sources.
- Removing the old format Unicode data earlier dumped from UnicodeData.txt
(versions 3.0.0 and 5.2.0) from ctype-utf8.c.
Adding Unicode data in the new format into separate header files,
to maintain the code easier:
- ctype-unicode300-casefold.h
- ctype-unicode300-casefold-tr.h
- ctype-unicode300-general_ci.h
- ctype-unicode300-general_mysql500_ci.h
- ctype-unicode520-casefold.h
- Adding a new file ctype-unidata.c as an aggregator for
the header files listed above.
This is a non-functional change and should not change the server behavior.
Casefolding information is now stored in items of a new data type MY_CASEFOLD_CHARACTER:
typedef struct casefold_info_char_t
{
uint32 toupper;
uint32 tolower;
} MY_CASEFOLD_CHARACTER;
Before this change, casefolding tables for Asian collations were stored in:
typedef struct unicase_info_char_st
{
uint32 toupper;
uint32 tolower;
uint32 sort;
} MY_UNICASE_CHARACTER;
The "sort" member was not used in the code handling Asian collations,
it only wasted space.
(it's only used by Unicode _general_ci and _general_mysql500_ci collations).
Unicode collations (at least UCA and _bin) should also be refactored later,
but under terms of a separate task.
String length growth during upper/lower conversion
in Unicode collations depends only on the underlying MY_UNICASE_INFO
used in the collation.
Maintaining a separate member CHARSET_INFO::caseup_multiply and
CHARSET_INFO::casedn_multiply duplicated this information
and caused bugs like this (when MY_UNICASE_INFO and case??_multiply
when out of sync because of incomplete CHARSET_INFO initialization).
Fix:
Changing CHARSET_INFO::caseup_multiply and CHARSET_INFO::casedn_multiply
from members to virtual functions.
The virtual functions in Unicode collations calculate case conversion
growth factors from the MY_UNICASE_INFO. This guarantees that the growth
factors are always in sync with the MY_UNICASE_INFO.
Moving these members:
CHARSET_INFO *cs;
const MY_UCA_WEIGHT_LEVEL *level;
from my_uca_scanner to a new separate structure my_uca_scanner_param.
Rationale:
During a comparison of two strings these members were initialized two times
(one time for every string).
After the change these members initialized only one time inside
a shared instance of my_uca_scanner_param, and the instance is
shared between two scanners (its const address is passed as new a parameter
to the underlying scanner functions).
This change gives a slight performance improvement (~5%).
Adding two levels of optimization:
1. For every bytes pair [00..FF][00..FF] which:
a. consists of two ASCII characters or makes a well-formed two-byte character
b. whose total weight string fits into 4 weights
(concatenated weight string in case of two ASCII characters,
or a single weight string in case of a two-byte character)
c. whose weight is context independent (i.e. does not depend on contractions
or previous context pairs)
store weights in a separate array of MY_UCA_2BYTES_ITEM,
so during scanner_next() we can scan two bytes at a time.
Byte pairs that do not match the conditions a-c are marked in this array
as not applicable for optimization and scanned as before.
2. For every byte pair which is applicable for optimization in #1,
and which produces only one or two weights, store
weights in one more array of MY_UCA_WEIGHT2. So in the beginning
of strnncoll*() we can skip equal prefixes using an even more efficient
loop. This loop consumes two bytes at a time. The loop scans while the
two bytes on both sides produce weight strings of equal length
(i.e. one weight on both sides, or two weight on both sides).
This allows to compare efficiently:
- Context independent sequences consisting of two ASCII characters
- Context independent 2-byte characters
- Contractions consisting of two ASCII characters, e.g. Czech "ch".
- Some tricky cases: "ss" vs "SHARP S"
("ss" produces two weights, 0xC39F also produces two weights)
Adding a hash table for contractions.
The old code iterated through all items in MY_CONTRACTIONS,
and was much slower, especially for those contractions
in the end of the list.
- Added one neutral and 22 tailored (language specific) collations based on
Unicode Collation Algorithm version 14.0.0.
Collations were added for Unicode character sets
utf8mb3, utf8mb4, ucs2, utf16, utf32.
Every tailoring was added with four accent and case
sensitivity flag combinations, e.g:
* utf8mb4_uca1400_swedish_as_cs
* utf8mb4_uca1400_swedish_as_ci
* utf8mb4_uca1400_swedish_ai_cs
* utf8mb4_uca1400_swedish_ai_ci
and their _nopad_ variants:
* utf8mb4_uca1400_swedish_nopad_as_cs
* utf8mb4_uca1400_swedish_nopad_as_ci
* utf8mb4_uca1400_swedish_nopad_ai_cs
* utf8mb4_uca1400_swedish_nopad_ai_ci
- Introducing a conception of contextually typed named collations:
CREATE DATABASE db1 CHARACTER SET utf8mb4;
CREATE TABLE db1.t1 (a CHAR(10) COLLATE uca1400_as_ci);
The idea is that there is no a need to specify the character set prefix
in the new collation names. It's enough to type just the suffix
"uca1400_as_ci". The character set is taken from the context.
In the above example script the context character set is utf8mb4.
So the CREATE TABLE will make a column with the collation
utf8mb4_uca1400_as_ci.
Short collations names can be used in any parts of the SQL syntax
where the COLLATE clause is understood.
- New collations are displayed only one time
(without character set combinations) by these statements:
SELECT * FROM INFORMATION_SCHEMA.COLLATIONS;
SHOW COLLATION;
For example, all these collations:
- utf8mb3_uca1400_swedish_as_ci
- utf8mb4_uca1400_swedish_as_ci
- ucs2_uca1400_swedish_as_ci
- utf16_uca1400_swedish_as_ci
- utf32_uca1400_swedish_as_ci
have just one entry in INFORMATION_SCHEMA.COLLATIONS and SHOW COLLATION,
with COLLATION_NAME equal to "uca1400_swedish_as_ci", which is the suffix
without the character set name:
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.COLLATIONS
WHERE COLLATION_NAME LIKE '%uca1400_swedish_as_ci';
+-----------------------+
| COLLATION_NAME |
+-----------------------+
| uca1400_swedish_as_ci |
+-----------------------+
Note, the behaviour of old collations did not change.
Non-unicode collations (e.g. latin1_swedish_ci) and
old UCA-4.0.0 collations (e.g. utf8mb4_unicode_ci)
are still displayed with the character set prefix, as before.
- The structure of the table INFORMATION_SCHEMA.COLLATIONS was changed.
The NOT NULL constraint was removed from these columns:
- CHARACTER_SET_NAME
- ID
- IS_DEFAULT
and from the corresponding columns in SHOW COLLATION.
For example:
SELECT COLLATION_NAME, CHARACTER_SET_NAME, ID, IS_DEFAULT
FROM INFORMATION_SCHEMA.COLLATIONS
WHERE COLLATION_NAME LIKE '%uca1400_swedish_as_ci';
+-----------------------+--------------------+------+------------+
| COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT |
+-----------------------+--------------------+------+------------+
| uca1400_swedish_as_ci | NULL | NULL | NULL |
+-----------------------+--------------------+------+------------+
The NULL value in these columns now means that the collation
is applicable to multiple character sets.
The behavioir of old collations did not change.
Make sure your client programs can handle NULL values in these columns.
- The structure of the table
INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY was changed.
Three new NOT NULL columns were added:
- FULL_COLLATION_NAME
- ID
- IS_DEFAULT
New collations have multiple entries in COLLATION_CHARACTER_SET_APPLICABILITY.
The column COLLATION_NAME contains the collation name without the character
set prefix. The column FULL_COLLATION_NAME contains the collation name with
the character set prefix.
Old collations have full collation name in both FULL_COLLATION_NAME and
COLLATION_NAME.
SELECT COLLATION_NAME, FULL_COLLATION_NAME, CHARACTER_SET_NAME, ID, IS_DEFAULT
FROM INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY
WHERE FULL_COLLATION_NAME RLIKE '^(utf8mb4|latin1).*swedish.*ci$';
+-----------------------------+-------------------------------------+--------------------+------+------------+
| COLLATION_NAME | FULL_COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT |
+-----------------------------+-------------------------------------+--------------------+------+------------+
| latin1_swedish_ci | latin1_swedish_ci | latin1 | 8 | Yes |
| latin1_swedish_nopad_ci | latin1_swedish_nopad_ci | latin1 | 1032 | |
| utf8mb4_swedish_ci | utf8mb4_swedish_ci | utf8mb4 | 232 | |
| uca1400_swedish_ai_ci | utf8mb4_uca1400_swedish_ai_ci | utf8mb4 | 2368 | |
| uca1400_swedish_as_ci | utf8mb4_uca1400_swedish_as_ci | utf8mb4 | 2370 | |
| uca1400_swedish_nopad_ai_ci | utf8mb4_uca1400_swedish_nopad_ai_ci | utf8mb4 | 2372 | |
| uca1400_swedish_nopad_as_ci | utf8mb4_uca1400_swedish_nopad_as_ci | utf8mb4 | 2374 | |
+-----------------------------+-------------------------------------+--------------------+------+------------+
- Other INFORMATION_SCHEMA queries:
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS;
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.PARAMETERS;
SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES;
SELECT DEFAULT_COLLATION_NAME FROM INFORMATION_SCHEMA.SCHEMATA;
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.ROUTINES;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.EVENTS;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.EVENTS;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.ROUTINES;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.ROUTINES;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.TRIGGERS;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.TRIGGERS;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.VIEWS;
display full collation names, including character sets prefix,
for all collations, including new collations.
Corresponding SHOW commands also display full collation names
in collation related columns:
SHOW CREATE TABLE t1;
SHOW CREATE DATABASE db1;
SHOW TABLE STATUS;
SHOW CREATE FUNCTION f1;
SHOW CREATE PROCEDURE p1;
SHOW CREATE EVENT ev1;
SHOW CREATE TRIGGER tr1;
SHOW CREATE VIEW;
These INFORMATION_SCHEMA queries and SHOW statements may change in
the future, to display show collation names.
Implicit weights are now handled according to the Unicode version
(14.0.0 vs earlier versions).
- Adding a new member MY_UCA_INFO::version
- Copy logical positions and the version from "src_uca" to "new_uca"
in init_weight_level().
- Adding a "const MY_UCA_INFO *" parameter to a few functions
to know Unicode version to generate implicit weights accordingly:
- during the collation initialization time, to pages which are
a mixture of explicit and implicit weights
- during comparison time, for fully implicit pages
- uca-dump can now dump logical positions as a set of "#define" directives.
Logical positions for 4.0.0 and for 5.2.0 were calculated and put into
ctype-uca.c manually. That required some efforts by analyzing allkeys.txt
with help of grep and sort.
Now when defining a new MY_UCA_INFO it's possible to use the new #define's
instead of calculating logical positions manually.
Logical positions also print their weights in DUCET format as a comment
before the define:
/*
[.0000.0021.0002]
[.0000.0117.0002]
*/
The comment helps to know weight ranges on various levels,
which makes it easier to debug the code.
- uca-dump can now dump built-in DUCET contractions
- Adding a new uca-dump command line option --no-contractions, this is useful
if one needs to re-dump 4.0.0 and 5.2.0 data in ctype-uca.c compatible way.
- Adding a new uca-dump command line options --case-first=upper|level.
This can be useful if one need to dump with UPPER case first by default.
It's not yet decided if we'll use --case-first=upper during the dump though.
- Moving parts of the code from the main loop into separate functions
parse_chars() and parse_weights(). This allows to reuse the code between
single characters and contractions.
- Adding a new function my_ducet_weight_normalize(), to cut zero weights
from a weight string, e.g. [AAAA][0000][BBBB] -> [AAAA][BBBB].
This helps to reuse the code between single characters and contractions.
- Weight normalization is now done before printing, in separate loops inside
my_ducet_normalize(). Before this change, normalization was done during
priting, inside the printing loop. This helps to separate steps:
loading -> normalizing -> printing.
This makes it easier to follow what's going on, e.g. while debugging.
- Fixing ctype-uca.c to handle built-in contractions of any length.
Previously we had only built-in contractions in utf8mb4_thai_520_w2,
which contains only 2-character contractions.
1. Adding separate functions for different Unicode versions
- my_uca_520_implicit_weight_primary()
It calculates implicit weights according to the old algorithm
that we used to dump Unicode-5.2.0 weights.
- my_uca_1400_implicit_weight_primary()
It calculates implicit weights according to
https://unicode.org/reports/tr10/#Values_For_Base_Table
as of November 2021, Unicode version 14.0.0.
2. Adding the "@version" line recognition when dumping allkeys.txt.
Implicit weights are dumped according to @version.
3. Dumping the scanned version as a "#define"
4. Removing dumping MY_UCA_NPAGES, MY_UCA_NCHARS, MY_UCA_CMASK, MY_UCA_PSHIFT,
as they are defined in ctype-uca.c. Removing dumping of "main()", it's not
needed. The intent is to generate an *.h file which can be put directly
to the MariaDB source tree.
5. Adding a structure MY_DUCET. It now contains weights for single
characters and version related members. Later we'll add contractions
and logical positions in here.
- Adding uca-dump into build targets
- Adding ctype-uca.h and moving implicit weight related routines there
- Reusing implicit weight routines in ctype-uca.c and uca-dump.c
- Adding handling of command line arguments to uca-dump
- Fixing some compile-time warnings in uca-dump.c
The weight scanner routine scanner_next() did not properly handle the cases
when a contraction produces no weights (is ignorable).
Adding a helper routine my_uca_scanner_set_weight() and using
it in all cases:
- A single ASCII character
- A contraction starting with an ASCII character
- A multi-byte character
- A contraction starting with a multi-byte character
Also adding two other helper routines:
- my_uca_scanner_next_expansion_weight()
- my_uca_scanner_set_weight_outside_maxchar()
to avoid using scanner->wbeg directly inside scanner_next().
This reduces the probability of similar future bugs.
This patch prepares the code for upcoming changes:
MDEV-27009 Add UCA-14.0.0 collations
MDEV-27042 UCA: Resetting contractions to ignorable does not work well
1. Adding "const" qualifiers to return type and parameters in functions:
- my_uca_contraction2_weight()
- my_wmemcmp()
- my_uca_contraction_weight()
- my_uca_scanner_contraction_find()
- my_uca_previous_context_find()
- my_uca_context_weight_find()
2. Adding a helper function my_uca_true_contraction_eq()
3. Changing the way how scanner->wbeg is set during context weight handling.
It was previously set inside functions:
- my_uca_scanner_contraction_find()
- my_uca_previous_context_find()
Now it's set inside scanner_next(), which makes the code more symmetric
for context-free and context-dependent sequences.
This makes then upcoming fix for MDEV-27042 simpler.
This change removed 68 explict strlen() calls from the code.
The following renames was done to ensure we don't use the old names
when merging code from earlier releases, as using the new variables
for print function could result in crashes:
- charset->csname renamed to charset->cs_name
- charset->name renamed to charset->coll_name
Almost everything where mechanical changes except:
- Changed to use the new Protocol::store(LEX_CSTRING..) when possible
- Changed to use field->store(LEX_CSTRING*, CHARSET_INFO*) when possible
- Changed to use String->append(LEX_CSTRING&) when possible
Other things:
- There where compiler issues with ensuring that all character set names
points to the same string: gcc doesn't allow one to use integer constants
when defining global structures (constant char * pointers works fine).
To get around this, I declared defines for each character set name
length.
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 easiest way to compile and test the server with UBSAN is to run:
./BUILD/compile-pentium64-ubsan
and then run mysql-test-run.
After this commit, one should be able to run this without any UBSAN
warnings. There is still a few compiler warnings that should be fixed
at some point, but these do not expose any real bugs.
The 'special' cases where we disable, suppress or circumvent UBSAN are:
- ref10 source (as here we intentionally do some shifts that UBSAN
complains about.
- x86 version of optimized int#korr() methods. UBSAN do not like unaligned
memory access of integers. Fixed by using byte_order_generic.h when
compiling with UBSAN
- We use smaller thread stack with ASAN and UBSAN, which forced me to
disable a few tests that prints the thread stack size.
- Verifying class types does not work for shared libraries. I added
suppression in mysql-test-run.pl for this case.
- Added '#ifdef WITH_UBSAN' when using integer arithmetic where it is
safe to have overflows (two cases, in item_func.cc).
Things fixed:
- Don't left shift signed values
(byte_order_generic.h, mysqltest.c, item_sum.cc and many more)
- Don't assign not non existing values to enum variables.
- Ensure that bool and enum values are properly initialized in
constructors. This was needed as UBSAN checks that these types has
correct values when one copies an object.
(gcalc_tools.h, ha_partition.cc, item_sum.cc, partition_element.h ...)
- Ensure we do not called handler functions on unallocated objects or
deleted objects.
(events.cc, sql_acl.cc).
- Fixed bugs in Item_sp::Item_sp() where we did not call constructor
on Query_arena object.
- Fixed several cast of objects to an incompatible class!
(Item.cc, Item_buff.cc, item_timefunc.cc, opt_subselect.cc, sql_acl.cc,
sql_select.cc ...)
- Ensure we do not do integer arithmetic that causes over or underflows.
This includes also ++ and -- of integers.
(Item_func.cc, Item_strfunc.cc, item_timefunc.cc, sql_base.cc ...)
- Added JSON_VALUE_UNITIALIZED to json_value_types and ensure that
value_type is initialized to this instead of to -1, which is not a valid
enum value for json_value_types.
- Ensure we do not call memcpy() when second argument could be null.
- Fixed that Item_func_str::make_empty_result() creates an empty string
instead of a null string (safer as it ensures we do not do arithmetic
on null strings).
Other things:
- Changed struct st_position to an OBJECT and added an initialization
function to it to ensure that we do not copy or use uninitialized
members. The change to a class was also motived that we used "struct
st_position" and POSITION randomly trough the code which was
confusing.
- Notably big rewrite in sql_acl.cc to avoid using deleted objects.
- Changed in sql_partition to use '^' instead of '-'. This is safe as
the operator is either 0 or 0x8000000000000000ULL.
- Added check for select_nr < INT_MAX in JOIN::build_explain() to
avoid bug when get_select() could return NULL.
- Reordered elements in POSITION for better alignment.
- Changed sql_test.cc::print_plan() to use pointers instead of objects.
- Fixed bug in find_set() where could could execute '1 << -1'.
- Added variable have_sanitizer, used by mtr. (This variable was before
only in 10.5 and up). It can now have one of two values:
ASAN or UBSAN.
- Moved ~Archive_share() from ha_archive.cc to ha_archive.h and marked
it virtual. This was an effort to get UBSAN to work with loaded storage
engines. I kept the change as the new place is better.
- Added in CONNECT engine COLBLK::SetName(), to get around a wrong cast
in tabutil.cpp.
- Added HAVE_REPLICATION around usage of rgi_slave, to get embedded
server to compile with UBSAN. (Patch from Marko).
- Added #ifdef for powerpc64 to avoid a bug in old gcc versions related
to integer arithmetic.
Changes that should not be needed but had to be done to suppress warnings
from UBSAN:
- Added static_cast<<uint16_t>> around shift to get rid of a LOT of
compiler warnings when using UBSAN.
- Had to change some '/' of 2 base integers to shift to get rid of
some compile time warnings.
Reviewed by:
- Json changes: Alexey Botchkov
- Charset changes in ctype-uca.c: Alexander Barkov
- InnoDB changes & Embedded server: Marko Mäkelä
- sql_acl.cc changes: Vicențiu Ciorbaru
- build_explain() changes: Sergey Petrunia
This patch ensures that all identical character sets shares the same
cs->csname.
This allows us to replace strcmp() in my_charset_same() with comparisons
of pointers. This fixes a long standing performance issue that could cause
as strcmp() for every item sent trough the protocol class to the end user.
One consequence of this patch is that we don't allow one to add a character
definition in the Index.xml file that changes the csname of an existing
character set. This is by design as changing character set names of existing
ones is extremely dangerous, especially as some storage engines just records
character set numbers.
As we now have a hash over character set's csname, we can in the future
use that for faster access to a specific character set. This could be done
by changing the hash to non unique and use the hash to find the next
character set with same csname.
main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
Additional changes:
1. Adding a fast path for ASCII characters
2. Adding dedicated MY_COLLATION_HANDLERs for collations with no contractions
(for utf8 and for utf8mb4 character sets). The choice between
the full-featured handler and the "no contraction" handler is
made at the collation initialization time.
Synchronizing sources in:
- my_wildcmp_uca_impl() handling utf8_unicode_ci
- my_wildcmp_unicode_impl() handling utf8_general_ci
The latter has already had a fix for a similar MySQL bug in utf8_general_ci:
Bug#11754 SET NAMES utf8 followed by SELECT "A\\" LIKE "A\\" returns 0
So fix is now propagated to utf8_unicode_ci.
