This merges the patch series that fixes a lot of missing validation
checks for read_log_event(). The merge includes a few added fixes that
are needed in new code introduced in 13.1.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
This merges the patch series that fixes a lot of missing validation
checks for read_log_event(). The merge includes a few added fixes that
are needed in new code introduced in 12.3.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
my_strntoull10rnd_8bit() did not set *error when a signed negative value
was exactly LONGLONG_MIN (-9223372036854775808): that path returned the
value and left *error untouched. Callers passing an uninitialized
"int error", such as the associative array key conversion in
Type_handler_assoc_array, then read a garbage value and raised a
spurious ER_WRONG_VALUE. Field_num::get_int() and Field_year::store()
also pass an uninitialized error, and my_strntoull10rnd_mb2_or_mb4()
calls this function too.
Fix: initialize *error to 0 at function entry, like the sibling
my_strntoll_8bit() and my_strntoll_mb2_or_mb4() do, so that no exit
path can leave it unset.
The bug was introduced by commit 031f11717d (Fix all warnings given by
UBSAN, 2021-04-18), which started skipping the *error assignment when
the value equals LONGLONG_MIN.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
This SQL script failed:
SET NAMES latin1 COLLATE latin1_swedish_ci;
CREATE OR REPLACE VIEW v1 AS SELECT 'Y' AS c1;
SET NAMES big5 COLLATE big5_chinese_ci;
SELECT * FROM v1 WHERE c1='y';
with the following error:
ERROR 1267 (HY000): Illegal mix of collations
(latin1_swedish_ci,COERCIBLE) and (big5_chinese_ci,COERCIBLE)
for operation '='
Note, latin1_swedish_ci and big5_chinese_ci are used here as examples.
The error also happened with different collation combinations.
Fix main idea:
If two collations have equal comparison rules (known as "tailoring")
on a given character repertoire,
like latin1_swedish_ci and big5_chinese_ci on ASCII letters,
then the "Illegal mix of collations" error can be avoided in
a comparison operator. We can choose any of the sides as the operation
effective collation - the result will be equal.
This optimization is not applied when at least one side has an explicit
COLLATE clause. Two explicit COLLATE clauses in one comparison are
already illegal when the character sets are the same, so for
consistency this stays illegal when the character sets differ too.
Most important details:
- Splitting enum_repertoire_t into smaller subsets,
for better repertoire granularity.
A variable holding a repertoire value can now have multiple
MY_REPERTOIRE_XXX flags set.
This patch implements detecting tailoring equality
on these repertoires:
* MY_REPERTOIRE_ASCII_DIGITS - [0..9]
* MY_REPERTOIRE_ASCII_MINUS_DOT_DIGITS - [-.0..9], e.g. '-10.5'.
It consists of the new bits MY_REPERTOIRE_ASCII_MINUS and
MY_REPERTOIRE_ASCII_DOT. They were a part of
MY_REPERTOIRE_ASCII_NOT_IDENT before. As a result, the numeric values
of MY_REPERTOIRE_ASCII and MY_REPERTOIRE_UNICODE30 changed
(223 and 255).
* MY_REPERTOIRE_ASCII_ALNUM - [A..Z,a..z,0..9].
* MY_REPERTOIRE_ASCII_IDENT - ALNUM + underscore
* MY_REPERTOIRE_ASCII - the entire range U+0000..U+007F
- Adding a new virtual function "tailoring" in my_collation_handler_st.
It returns the tailoring on the given repertoire for the given
collation.
If cs1->coll->tailoring(cs1, some_repertoire) returns {0,0},
it means the illegal mix optimization cannot be used
for this collation on the given repertoire.
If these calls:
tr1= cs1->coll->tailoring(cs1, some_repertoire);
tr2= cs2->coll->tailoring(cs2, some_repertoire);
return both non-NULL results and tr1.str==tr2.str,
then these collations are equal on the given repertoire
and are mutually replaceable for a comparison operator,
so "Illegal mix of collations" can be avoided.
- Tailoring strings are shared constants my_tailoring_str_*
(strings/strings_def.h). Tailorings are compared by the string
pointer, so tailoring() implementations return strings only from
these constants. The strings do not depend on PAD/NOPAD.
- my_string_repertoire() for ucs2, utf16, utf32 and NONASCII 8bit
character sets no longer stops at the first bad byte sequence with
the repertoire found so far, which could be MY_REPERTOIRE_NONE
(compatible with everything). It returns MY_REPERTOIRE_EXTENDED
for such strings. A unit test was added into unittest/strings.
- Adding CHARSET_INFO::is_ascii_superset(). It tells if a character set
can store all ASCII characters (it is false for swe7).
It is used in Item_func_conv_charset to calculate "safe", and in
left_is_algorithmically_simpler() to prefer other character sets
to those where ASCII strings cannot be converted safely.
- DBUG_ASSERTs were added into mysys/charset.c, to check that
the "tailoring" method is set in collation handlers when a collation
is added: compiled-in, from ctype-extra.c, or loaded from Index.xml.
- Adding a new function my_collations_equal_on_repertoire(cs1, cs2,
repertoire) in strings/. It tells if two collations are equal on
the repertoire, taking tailoring() results and PAD/NOPAD and the UCA
version into account. Callers do not compare tailoring() results
directly, so the way tailorings are compared (currently by the pointer
to the shared constant string) is private to strings/ and can be
extended later, e.g. for UCA collations on MY_REPERTOIRE_UNICODE30.
- Adding a new method DTCollation::aggregate_by_tailoring().
Collations with different MY_CS_NOPAD are never compatible.
UCA collations of different versions are not compatible on
the repertoire with ASCII punctuation, as the UCA version
affects its order (e.g. UCA-6.2.0 moved GRAVE ACCENT
and CIRCUMFLEX ACCENT after PERCENT SIGN).
- DTCollation::aggregate() now makes the repertoire of the result cover
the repertoires of both sides in all successful branches.
Before, set(dt) replaced the repertoire with the repertoire of the
winner side only, so the result could have a too narrow repertoire,
e.g. IF(1, 1.5, HEX(255)) had MY_REPERTOIRE_ASCII_ALNUM although the
value '1.5' has a punctuation character. With the more granular
repertoires this could wrongly allow mixing collations which are
equal on ALNUM but different on punctuation.
- Adding a new flag MY_COLL_ALLOW_BY_TAILORING.
It indicates to DTCollation::aggregate() that the illegal
mix optimization by repertoire can be used in the given context.
MY_COLL_CMP_CONV now includes MY_COLL_ALLOW_BY_TAILORING.
Note, only comparison operators pass this flag.
Functions returning a string result do not pass this flag,
because in operations like CONCAT(a,b) we still need to evaluate
precisely the collation of the result - we cannot just choose
a collation of one of the sides (even if they are compatible
on the given repertoire). This also applies to ExtractValue()
and UpdateXML(), which now aggregate their arguments without
this flag.
- As in my_repertoire_t the value MY_REPERTOIRE_ASCII is now a set of
bits rather than a single bit, the way to detect "is only ASCII"
repertoires has changed in the code.
For example:
// repertoire *IS* ascii
if (repertoire == MY_REPERTOIRE_ASCII)
has changed in multiple places in the code to
// repertoire *HAS* only ascii characters
if (my_repertoire_is_subset_of(repertoire, MY_REPERTOIRE_ASCII))
The new function my_repertoire_is_subset_of() in m_ctype.h
is used for this purpose in C code. In C++ code
DTCollation::repertoire_is_subset_of() is used, e.g.:
if (collation.repertoire_is_subset_of(MY_REPERTOIRE_ASCII))
- Repertoire of some expressions was adjusted to the new meaning:
* Item_null now has MY_REPERTOIRE_NONE (was ASCII).
* MY_LOCALE::repertoire() now returns MY_REPERTOIRE_UNICODE30
(was EXTENDED).
* Lex_string_with_metadata_st::repertoire(cs) now scans the string
contents to detect the actual repertoire.
* HEX() now has MY_REPERTOIRE_ASCII_ALNUM.
* DATE_FORMAT() decides on MY_REPERTOIRE_EXTENDED using the locale
which is actually used: the explicit third argument, or
@@lc_time_names. It was always @@lc_time_names before.
A non-constant locale argument is assumed to be non-ASCII.
* QUOTE, MAKE_SET, EXPORT_SET, LPAD, RPAD, GROUP_CONCAT, JSON_ARRAY,
JSON_OBJECT and JSON_OBJECTAGG add the repertoire of the extra
characters they put into the result (quotes, separators, padding,
brackets).
* LOWER() and UPPER() add the letters of both cases to the repertoire,
because the result can contain letters of the opposite case.
In Turkish collations they also add MY_REPERTOIRE_EXTENDED, as an
ASCII letter can be converted to a non-ASCII one (I -> dotless i).
Unicode collations are detected by the new member
casefold_info_st::can_convert_to_non_ascii_on_casefolding,
simple 8bit collations by to_lower['I'] and to_upper['i'].
- Lex_string_with_metadata_st::repertoire(cs) now scans a string literal
for any byte oriented character set (mbminlen==1), not only for
ASCII based ones. It was assumed to have the full repertoire for swe7,
which is not ASCII based. The scan is done by Unicode code points, so
swe7 strings with digits and letters get a narrow repertoire, while
e.g. 0x5B (LATIN CAPITAL LETTER A WITH DIAERESIS in swe7) is non-ASCII.
Therefore swe7_swedish_ci can be mixed with other collations now,
in the same way as other collations with MY_CS_IDENT_CASEUP_CI.
The test func_time was adjusted: a swe7 literal ' ull' with ASCII
characters is now safe to convert, the error is still tested for '[ull'.
- cp1250_czech_cs sorts -, . and 0..9 in the code point order, so it gets
the MINUS_DOT_DIGITS tailoring. latin2_czech_cs gets only DIGITS,
as it sorts the minus and the dot differently. Both were verified
with ctype_digits_verify.
- The tis620 collations now set CHARSET_INFO::tab_to_uni (was NULL),
so my_charset_is_ascii_based() is true for tis620.
It was false for tis620, although tis620 is ASCII compatible.
Therefore tis620 string literals were always considered to have
a non-ASCII repertoire, and the repertoire optimizations did not work
for them. Now ASCII-only tis620 literals are detected as ASCII.
This changes the result of subselect_extra_no_semijoin
from an error to success.
- tis620_thai_ci and tis620_thai_nopad_ci fold letters to lower case
and then compare by the code point on the entire ASCII range
(the Thai specific rules affect only non-ASCII characters).
A new function my_tailoring_ascii_casedn_ci() returns tailorings
for such collations on ALNUM, IDENT and ASCII. For example, the
underscore sorts before the letters, unlike in the caseup tailorings.
- New flags were added for CHARSET_INFO::state
* MY_CS_ASCII_CASEUP_CI - for simple 8bit case insensitive collations.
It means that this collation has no irregularities on the ASCII
repertoire, and converts lower case letters to upper case ones,
so the underscore sorts after the letters (with an upper to lower
case conversion it would sort before the letters).
* MY_CS_IDENT_CASEUP_CI - for simple 8bit case insensitive collations.
It means that this collation has no irregularities on the IDENT
repertoire (but can have irregularities say on punctuation).
* MY_CS_ASCII_STD_UCA - for UCA collations.
It means that a UCA collation does not reorder ASCII characters.
* MY_CS_DIGITS_STD - for any collation. It means that the ASCII digits
0..9 are sorted in the code point order and are not tailored, and,
for PAD collations, the space sorts before the digits. Strings of
digits are compared in the same way in all such collations, even if
they have irregularities on letters (latin7, cp866, czech, danish,
turkish UCA, etc.), or differ by case sensitivity. It is detected
from sort_order for 8bit collations, and from the tailoring rules
for UCA collations. Collations with MY_CS_DIGITS_STD still must have
the same PAD/NOPAD attribute.
* MY_CS_ASCII_MINUS_DOT_DIGITS - for any collation. Means
MY_CS_DIGITS_STD, and additionally the minus sorts before the dot,
which sorts before the digits (and the space sorts before the minus
in PAD collations). Strings like '-10.5' are compared in the same
way in all such collations. It is detected from sort_order for simple
8bit collations (my_coll_init_simple()), and from the tailoring rules
for UCA collations. For the multi-byte collations big5_chinese_ci,
gbk_chinese_ci, gb2312_chinese_ci and sjis_japanese_ci it is declared
by my_tailoring_ident_caseup_ci_generic(). The flags MY_CS_DIGITS_STD
and MY_CS_ASCII_MINUS_DOT_DIGITS are stored in ctype-extra.c for
compiled collations (conf_to_src.c prints them), and the detection is
skipped for a collation which already has any of the repertoire flags
(MY_CS_REPERTOIRE_FLAGS).
- strings/conf_to_src.c was modified to detect and print
MY_CS_ASCII_CASEUP_CI and MY_CS_IDENT_CASEUP_CI flags.
- strings/ctype-extra.c was regenerated with new flags.
- 8bit collations are not given MY_CS_ASCII_CASEUP_CI and
MY_CS_IDENT_CASEUP_CI if they are PAD and the space does not sort
before the digits. A shorter string is padded with spaces for
comparison, so the position of the space matters even for strings
without spaces ("ab" is compared to "abc" as "ab " to "abc").
A test collation latin1_space_after_letters_ci was added to
mysql-test/std_data/ldml/ for this. ctype-extra.c does not change.
- The initializer of my_collation_cs_handler in ctype-utf8.c
(utf8mb3_general_cs, under HAVE_UTF8_GENERAL_CS) was fixed to match
my_collation_handler_st: the missing get_id and get_collation_name
members were added, so that eq_collation was not initialized in their
place, and the new member "tailoring" is now set to my_tailoring_none.
- Results of the existing tests func_str, func_test, ps, view
and subselect_sj changed from "Illegal mix of collations" to success.
In these tests ASCII-only strings were compared using collations
with equal tailoring on ASCII, e.g. latin1_swedish_ci with
latin2_general_ci (func_str, ps), koi8r_general_ci with
latin1_swedish_ci (func_test), latin1_general_ci with
latin1_swedish_ci on letters and digits (view), cp932_japanese_ci
with latin1_swedish_ci (subselect_sj).
Such comparisons are now allowed.
Cases with collations that are still incompatible on ASCII,
e.g. latin7_general_ci, were added to the tests and still fail.
- Adding a number of MTR tests in
plugin/func_test/mysql-test/func_test/.
They display a tailoring by collation name and repertoire as
returned by:
cs->coll->tailoring(cs, some_repertoire)
A dynamically linked plugin function collation_tailoring() was added
for the purpose of these tests. Tailorings do not depend on PAD/NOPAD
and on the UCA version, so the function shows "[nopad]" for NOPAD
collations, and "[version X.Y.Z]" for UCA collations on the ASCII
repertoire. The version is formatted by a new class UCAVersion,
which uses a new method CharBuffer::append_uint8().
- Adding the test plugin/func_test/mysql-test/func_test/
ctype_caseup_ci_verify.test. It checks the order of ASCII characters
for all collations declared "caseup CI" on the ASCII or IDENT range.
- Adding the test plugin/func_test/mysql-test/func_test/
collation_tailoring_args.test. It checks the arguments of the plugin
function collation_tailoring(): the repertoire passed by name or by
number, and the NULL results for unknown names.
- Adding the test plugin/func_test/mysql-test/func_test/ctype_ldml.test.
It displays the tailorings of collations loaded at runtime from
Index.xml: simple 8bit collations (flags detected from the weights)
and Unicode collations (LDML rules which do or do not reorder ASCII).
- Adding a number of MTR tests mysql-test/main/ctype_xxx_tailoring.test
They display two-dimensional charts showing which collations
are compatible on which repertoires.
Tests for DATE_FORMAT() with an explicit locale were added to
ctype_big5_tailoring.test, ctype_cp932_tailoring.test and
ctype_latin5_tailoring.test, which also has the chart for latin5.
- Adding a number of MTR tests in the form of the originally
reported script for various collations:
SELECT Insert_priv FROM mysql.user WHERE Insert_priv='...';
The repeated blocks of queries are shared through
mysql-test/include/
ctype_tailoring_0{1,2,3}_mysql_user_Insert_priv*.inc.
- Adding tests to ctype_cp932.test checking that ExtractValue() and
UpdateXML() still raise "Illegal mix of collations".
A field of an element of an associative array of RECORDs, passed to
an OUT or INOUT parameter of a stored routine, crashed the server:
CREATE PROCEDURE p1(a OUT INT) AS BEGIN a:= 7; END;
DECLARE
TYPE rec_t IS RECORD (i INT, s VARCHAR(10));
TYPE tab_t IS TABLE OF rec_t INDEX BY INT;
t tab_t:= tab_t(1 => rec_t(0, 'x'));
BEGIN
p1(t(1).i);
END;
There were three problems:
- Item_splocal_assoc_array_element_field inherited set_value() of
Item_splocal_row_field_by_name, which treated the associative array
variable as a ROW variable (assertion failure in
sp_rcontext::virtual_tmp_table_for_row()). Added
Item_splocal_assoc_array_element_field::set_value(), which stores the
value into the field of the element.
- Before the call, sp_head::bind_input_param() destructed the whole
variable for an OUT argument, even if the argument was only a part of
the variable (a ROW field, an assoc array element or its field), so
the other elements of the array were lost: after p1(a0(2)), the array
a0(1), a0(2), a0(3) had only one element left. Added
Item_splocal::is_part_of_variable().
- sp_head::bind_output_param() evaluated the actual argument in the
context of the callee. For arguments like t(i) or t(i).field this
resolved the variables t and i in a wrong context. Now the argument
is evaluated in the context of the caller.
The second problem also affected a SYS_REFCURSOR field of a ROW variable
passed as an OUT argument: the cursors in the other fields of the ROW
variable were closed. Now they are kept.
Known limitations, not changed by this fix:
- The actual OUT argument is evaluated when the value is copied back,
not when the routine is called. If an earlier OUT argument of the same
call changes the variable used as the key, as in CALL p(i, a0(i)), the
new value of the key is used.
- For an OUT argument which is a part of a variable (a ROW field, an
assoc array element or its field), only the destruct of the whole
variable is skipped, the part itself is not destructed. A
SYS_REFCURSOR field of a ROW stays open during the call and is
released when the new value is copied back.
Tests: sp-assoc-array (OUT and INOUT elements and fields of elements,
NULL key, element deleted by the callee, ROW and RECORD fields) and
type_sys_refcursor-type_row-debug (SYS_REFCURSOR fields of a ROW
variable).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Type_handler_assoc_array::sp_variable_declarations_finalize() prepared
the member definitions of the RECORD (sp_type_def_record::field) in
place. These definitions are shared by all variables of the RECORD type
and by all associative arrays of it, so they were prepared more than
once, e.g. after declaring an associative array and then a RECORD
variable. Preparing a definition twice is wrong: a MEDIUMTEXT member
became TINYTEXT, so the values were truncated to 255 characters, and a
SET member crashed the server with an assertion failure in
store_lowendian(). The check based on FIELDFLAG_MAYBE_NULL, which tried
to prevent the second preparation, did not work.
Prepare a copy of the definitions (Row_definition_list::deep_copy()),
like Type_handler_row::sp_variable_declarations_finalize() does for a
variable of the RECORD type.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
1. Built-in plugins (plugin_init):
A non-ASCII builtin name is a developer error. Added a check
using my_string_repertoire() that prints an error via
print_init_failed_error() and returns 1 to abort server startup.
2. Dynamically loaded plugins (plugin_add):
Added a pre-validation loop before the registration loop. If any
plugin name in the .so is non-ASCII, the entire .so is rejected
before any plugin is registered, preventing partial state where
valid plugins from the same .so get left INACTIVE in the hash.
Added test plugins and MTR tests to verify both rejection of
non-ASCII named plugins and successful loading of ASCII named plugins.
The test fails on random secret with backslash.
The random handlersocket_plain_secret is generated from the '0'..'z'
range, which includes the backslash. The test masked the secret with
--replace_result $HS_SECRET, and mysqltest parses --replace_result
arguments with backslash escapes, so the search string lost the
backslash and did not match the output. The unmasked secret then
appeared in the result (about 19% of runs).
The fix masks the secret in SQL: IF(variable_name LIKE
'handlersocket_plain_secret%', 'HS_SECRET', variable_value), which does
not depend on the secret value.
SET sql_mode=ORACLE;
DELIMITER $$
CREATE OR REPLACE PACKAGE pkg AS
-- Declare a package public data type
TYPE varchar_array IS TABLE OF VARCHAR(2000) INDEX BY INTEGER;
END;
$$
DELIMITER ;
DELIMITER $$
CREATE OR REPLACE PROCEDURE p1 AS
v pkg.varchar_array; -- Use the package public data type
BEGIN
v(0):='test';
SELECT v(0);
END;
$$
DELIMITER ;
Note, the change is done only for sql_mode=ORACLE, because the TYPE
declaration is not available for the default mode.
Where package-wide types are available
--------------------------------------
- Variabe list type:
DECLARE var pkg1.type1;
- RETURN type for a package routine:
CREATE FUNCTION .. RETURN pkg1.type1 ...
- Parameter type for a package routine:
PROCEDURE p1(param1 pkg1.type1);
- Assoc array element type:
TYPE assoc1_t IS TABLE OF pkg1.type1 ...
- REF CURSOR RETURN type:
TYPE cur1_t IS REF CURSOR RETURN pkg1.type1;
Change details
--------------
- Adding a member Lex_length_and_dec_st::m_foreign_module_type
It's set to true when the data type was initialized from a TYPE
in foreign routine (e.g. in PACKAGE spec).
It's needed to prevent use of qualified identifiers in public contexts,
i.e. in schema public routine parameter types and schema publuc function
RETURN types.
Adding a helper method sp_head::check_applicability() which prevents
use of qualified types in public context.
- Adding a helper method sp_head::raise_unknown_data_type().
- Adding methods LEX::set_field_type_typedef_package_spec() for
2-step and 3-step qualified indentifiers.
It's used in field_type_all_with_typedefs which covers cases:
- Variabe list type : DECLARE var pkg1.type1;
- RETURN type : CREATE FUNCTION .. RETURN pkg1.type1 ...
- Parameter type : PROCEDURE p1(param1 pkg1.type1);
- Assoc array element type : TYPE assoc1_t IS TABLE OF pkg1.type1 ...
- Adding a method LEX::declare_type_ref_cursor_return_typedef().
It handles cases when a new TYPE REF CURSOR RETURN is declared,
for both for qualified RETURN types and non-qualified RETURN types:
- TYPE cur0_t IS REF CURSOR RETURN rec1_t;
- TYPE cur0_t IS REF CURSOR RETURN pkg1.rec1_t;
- TYPE cur0_t IS REF CURSOR RETURN db1.pkg1.rec1_t;
The code was moved from LEX::declare_type_ref_cursor() into
LEX::declare_type_ref_cursor_return_typedef() and extended
to cover qualified RETURN types.
- Adding a method Sql_path::find_package_spec_type().
It iterates through all schemas specified in @@path and searches
for the given type in the given package.
- Adding a helper method sp_pcontext::type_defs_add_ref_cursor()
to reuse the code.
- Adding a new method sp_package::get_typedef() to search
for TYPE definitions in PACKAGE specifications.
- Adding a new method sp_head::get_typedef_package_spec()
to search for TYPE definitions used by a PROCEDURE or FUNCTION.
- Adding a helper method
Sp_handler::sp_cache_routine_reentrant_suppress_errors
Adding a method Sp_handler::find_package_spec().
plugins are not yet supported in replay mode.
So, disabling tests type_test.type_test_int8, and type_test.type_test_double
to be run in replay-server mode
qc_info cannot parse query cache key, this cannot be done
without changing query cache key format.
let's limit the (possibly incorrect) db_length to make sure
it does not extend beyond the db name end, this way there will be no
OOB reads and no information leak.
* reduced PARSEC_ITERATIONS_MAX because PKCS5_PBKDF2_HMAC() takes
a signed int
* instead of checking for '0'..'L' range (which includes punctuation,
check for the valid result of base62_to_uchar()
* add a connection test with non-default parsec_iterations
* make parsec_iterations a normal command line option
* update C/C to allow larger number of iterations in the client parsec
This patch adds a global and session level plugin variable
parsec_iterations to define the number of iterations to be
used when generating the key corresponding to the password.
It has a default value, lower and upper bounds.
THDVAR(thd, loc_info) can return NULL if the plugin was previously
uninstalled. get_loc_info() and its callers dereferenced it.
Guard against a NULL loc_info in get_loc_info(), auditing() and
log_current_query(). Such a session is not audited.
The plugin used clock() only to timestamp cache entries and measure
elapsed time against millisecond timeouts. As shown in MDEV-12345,
clock() is prohibitively expensive, and we do not need per-thread or
per-process CPU time here, only time differences.
Replace clock()/clock_t with the monotonic std::chrono::steady_clock.
Timeouts are kept as std::chrono::milliseconds
This statement:
OPEN c FOR 'dynamic sql'
was only allowed for SYS_REFCURSOR.
Additionally allow it for REF CURSOR with no RETURN clause, e.g.:
TYPE cur0_t IS REF CURSOR; -- No RETURN clause - OK for OPEN FOR
Note, REF CURSORs with RETURN clause are still not allowed for dynamic OPEN,
as expected.