Passing a null pointer to a nonnull argument is not only undefined
behaviour, but it also grants the compiler the permission to optimize
away further checks whether the pointer is null. GCC -O2 at least
starting with version 8 may do that, potentially causing SIGSEGV.
After the MDEV-13118 fix there's no code in the server that
wants caseup/casedn to change the argument in place for simple
charsets. Let's remove this logic and always return the result in a
new string for all charsets, both simple and complex.
1. Removing the optimization that *some* character sets used in casedn()
and caseup(), which allowed (and required) to change the case in-place,
overwriting the string passed as the "src" argument.
Now all CHARSET_INFO's work in the same way:
non of them change the source string in-place, all of them now convert
case from the source string to the destination string, leaving
the source string untouched.
2. Adding "const" qualifier to the "char *src" parameter
to caseup() and casedn().
3. Removing duplicate implementations in ctype-mb.c.
Now both caseup() and casedn() implementations for all CJK character sets
use internally the same function my_casefold_mb()
(the former my_casefold_mb_varlen()).
4. Removing the "unused" attribute from parameters of some my_case{up|dn}_xxx()
implementations, as the affected parameters are now *used* in the code.
Previously these parameters were used only in DBUG_ASSERT().
This is a pre-requisite patch for:
- MDEV-8433 Make field<'broken-string' use indexes
- MDEV-8625 Bad result set with ignorable characters when using a prefix key
- MDEV-8626 Bad result set with contractions when using a prefix key
Adding a new virtual function MY_CHARSET_HANDLER::copy_abort().
Moving character set specific code into the correspoding implementations
(for simple, multi-byte and mbmaxlen>1 character sets).
The problem was that my_hash_sort didn't properly delete end-space characters properly, so strings that should compare
identically was seen as different strings. (Space was handled correctly, but not NBSP)
This caused duplicate key errors when a heap table was converted to Aria as part of overflow in group by.
Fixed by removing all characters that compares as end space when creating a hash.
Other things:
- Fixed that --sorted_results also works for errors in mysqltest.
- Speed up hash by not comparing strings that has different hash.
- Speed up many my_hash_sort functions by using registers to calculate hash instead of pointers.
This was previously done for some functions, but not for all.
- Made a macro of the hash function, to simplify code and to be able to experiment with new hash functions.
client/mysqltest.cc:
Fixed that --sorted_results also works for error messages.
mysql-test/r/ctype_partitions.result:
New test to ensure that partitions on hash works
mysql-test/suite/multi_source/gtid.result:
Updated result
mysql-test/suite/multi_source/gtid.test:
Test that --sorted_result works for error messages
mysql-test/suite/multi_source/gtid_ignore_duplicates.result:
Updated result
mysql-test/suite/multi_source/gtid_ignore_duplicates.test:
Updated result
mysql-test/suite/multi_source/load_data.result:
Updated result
mysql-test/suite/multi_source/load_data.test:
Updated result
mysql-test/t/ctype_partitions.test:
New test to ensure that partitions on hash works
storage/heap/hp_write.c:
Speed up hash by not comparing strings that has different hash.
storage/maria/ma_check.c:
Extra debug
strings/ctype-bin.c:
Use macro for hash function
strings/ctype-latin1.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-mb.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-simple.c:
Use macro for hash function
Use same variable names as in other my_hash_sort functions.
Update my_hash_sort_simple() to properly remove end space (patch by Bar)
strings/ctype-uca.c:
Ignore duplicated space inside strings and end space in my_hash_sort_uca(). This fixed MDEV-6255
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-ucs2.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-utf8.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/strings_def.h:
Made a macro of the hash function, to simplify code and to be able to experiment with new hash functions.
COLLATIONS ARE USED.
ISSUE :
-------
Code points of HALF WIDTH KATAKANA in SJIS/CP932 range from
A1 to DF. In function my_wildcmp_mb_bin_impl while comparing
such single byte code points, there is a code which compares
signed character with unsigned character. Because of this,
comparisons of two same code points representing a HALF
WIDTH KATAKANA character always fails.
Solution:
---------
A code point of HALF WIDTH KATAKANA at-least need 8 bits.
Promoting the variable from uchar to int will fix the issue.
mysql-test/t/ctype_cp932.test:
Tests which have conditions
LIKE 'STRING PATTERN WITH HALF WIDTH KATAKANA'.
strings/ctype-mb.c:
A code point of HALF WIDTH KATAKANA at-least need 8 bits.
Promoting the variable from uchar to int will fix the issue.
Description: A typo in create_tailoring() causes the "contraction_flags" to be written
into cs->contractions in the wrong place. This causes two problems:
(1) Anyone relying on `contraction_flags` to decide "could this character be
part of a contraction" is 100% broken.
(2) Anyone relying on `contractions` to determine the weight of a contraction
is mostly broken
Analysis: When we are preparing the contraction in create_tailoring(), we are corrupting the
cs->contractions memory location which is supposed to store the weights(8k) + contraction information(256 bytes). We started storing the contraction information after the 4k location. This is because of logic flaw in the code.
Fix: When we create the contractions, we need to calculate the contraction with (char*) (cs->contractions + 0x40*0x40) from ((char*) cs->contractions) + 0x40*0x40. This makes the "cs->contractions" to move to 8k bytes and stores the contraction information from there. Similarly when we are calculating it for like range queries we need to calculate it from the 8k bytes onwards, this can be done by changing the logic to (const char*) (cs->contractions + 0x40*0x40). And for ucs2 charsets we need to modify the my_cs_can_be_contraction_head() and my_cs_can_be_contraction_tail() to point to 8k+ locations.
includes:
* remove some remnants of "Bug#14521864: MYSQL 5.1 TO 5.5 BUGS PARTITIONING"
* introduce LOCK_share, now LOCK_ha_data is strictly for engines
* rea_create_table() always creates .par file (even in "frm-only" mode)
* fix a 5.6 bug, temp file leak on dummy ALTER TABLE
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
