SET NAMES utf8;

--echo #
--echo # MDEV-4425 REGEXP enhancements
--echo #

--echo #
--echo # Checking RLIKE
--echo #

# Checking that à is a single character
SELECT 'à' RLIKE '^.$';

# Checking \x{FFFF} syntax and case sensitivity
SELECT 'à' RLIKE '\\x{00E0}';
SELECT 'À' RLIKE '\\x{00E0}';
SELECT 'à' RLIKE '\\x{00C0}';
SELECT 'À' RLIKE '\\x{00C0}';
SELECT 'à' RLIKE '\\x{00E0}' COLLATE utf8_bin;
SELECT 'À' RLIKE '\\x{00E0}' COLLATE utf8_bin;
SELECT 'à' RLIKE '\\x{00C0}' COLLATE utf8_bin;
SELECT 'À' RLIKE '\\x{00C0}' COLLATE utf8_bin;

# Checking how (?i) and (?-i) affect case sensitivity
CREATE TABLE t1 (s VARCHAR(10) CHARACTER SET utf8);
INSERT INTO t1 VALUES ('a'),('A');
CREATE TABLE t2 (p VARCHAR(10) CHARACTER SET utf8);
INSERT INTO t2 VALUES ('a'),('(?i)a'),('(?-i)a'),('A'),('(?i)A'),('(?-i)A');
SELECT s,p,s RLIKE p, s COLLATE utf8_bin RLIKE p FROM t1,t2 ORDER BY BINARY s, BINARY p;
DROP TABLE t1,t2;


# Checking Unicode character classes
CREATE TABLE t1 (ch VARCHAR(22)) CHARACTER SET utf8;
CREATE TABLE t2 (class VARCHAR(32)) CHARACTER SET utf8;
INSERT INTO t1 VALUES ('Я'),('Σ'),('A'),('À');
INSERT INTO t1 VALUES ('я'),('σ'),('a'),('à');
INSERT INTO t1 VALUES ('㐗'),('갷'),('ප');
INSERT INTO t1 VALUES ('1'),('௨');
INSERT INTO t2 VALUES ('\\p{Cyrillic}'),('\\p{Greek}'),('\\p{Latin}');
INSERT INTO t2 VALUES ('\\p{Han}'),('\\p{Hangul}');
INSERT INTO t2 VALUES ('\\p{Sinhala}'), ('\\p{Tamil}');
INSERT INTO t2 VALUES ('\\p{L}'),('\\p{Ll}'),('\\p{Lu}'),('\\p{L&}');
INSERT INTO t2 VALUES ('[[:alpha:]]'),('[[:digit:]]');
SELECT class, ch, ch RLIKE class FROM t1, t2 ORDER BY class, BINARY ch;
DROP TABLE t1, t2;

# Checking that UCP is disabled by default for binary data
SELECT 0xFF RLIKE '\\w';
SELECT 0xFF RLIKE '(*UCP)\\w';

# newline character
SELECT '\n' RLIKE '(*CR)';
SELECT '\n' RLIKE '(*LF)';
SELECT '\n' RLIKE '(*CRLF)';
SELECT '\n' RLIKE '(*ANYCRLF)';
SELECT '\n' RLIKE '(*ANY)';

SELECT 'a\nb' RLIKE '(*LF)(?m)^a$';
SELECT 'a\nb' RLIKE '(*CR)(?m)^a$';
SELECT 'a\nb' RLIKE '(*CRLF)(?m)^a$';
SELECT 'a\nb' RLIKE '(*ANYCRLF)(?m)^a$';

SELECT 'a\rb' RLIKE '(*LF)(?m)^a$';
SELECT 'a\rb' RLIKE '(*CR)(?m)^a$';
SELECT 'a\rb' RLIKE '(*CRLF)(?m)^a$';
SELECT 'a\rb' RLIKE '(*ANYCRLF)(?m)^a$';

SELECT 'a\r\nb' RLIKE '(*LF)(?m)^a$';
SELECT 'a\r\nb' RLIKE '(*CR)(?m)^a$';
SELECT 'a\r\nb' RLIKE '(*CRLF)(?m)^a$';
SELECT 'a\r\nb' RLIKE '(*ANYCRLF)(?m)^a$';

#backreference
SELECT 'aa' RLIKE '(a)\\g1';
SELECT 'aa bb' RLIKE '(a)\\g1 (b)\\g2';

#repitition
SELECT 'aaaaa' RLIKE 'a{0,5}';
SELECT 'aaaaa' RLIKE 'a{1,3}';
SELECT 'aaaaa' RLIKE 'a{0,}';
SELECT 'aaaaa' RLIKE 'a{10,20}';

#Recursion
SELECT 'aabb' RLIKE 'a(?R)?b';
SELECT 'aabb' RLIKE 'aa(?R)?bb';

#subroutine
#SELECT 'abbbc' RLIKE '(a(b|(?1))*c)';
#SELECT 'abca' RLIKE '([abc])(?1){3}';

#Atomic grouping
SELECT 'abcc' RLIKE 'a(?>bc|b)c';
SELECT 'abc' RLIKE 'a(?>bc|b)c';

#lookahead - negative
SELECT 'ab' RLIKE 'a(?!b)';
SELECT 'ac' RLIKE 'a(?!b)';

#lookahead - positive
SELECT 'ab' RLIKE 'a(?=b)';
SELECT 'ac' RLIKE 'a(?=b)';

#lookbehind - negative
SELECT 'ab' RLIKE '(?<!a)b';
SELECT 'cb' RLIKE '(?<!a)b';

#lookbehind - positive
SELECT 'ab' RLIKE '(?<=a)b';
SELECT 'cb' RLIKE '(?<=a)b';

# named subpatterns
SELECT 'aa' RLIKE '(?P<pattern>a)(?P=pattern)';
SELECT 'aba' RLIKE '(?P<pattern>a)b(?P=pattern)';

#comments
SELECT 'a' RLIKE 'a(?#comment)';
SELECT 'aa' RLIKE 'a(?#comment)a';
SELECT 'aba' RLIKE 'a(?#b)a';

#ungreedy maching
#SELECT 'ddd <ab>cc</ab> eee' RLIKE '<.+?>';

#Extended character classes 
SELECT 'aaa' RLIKE '\\W\\W\\W';
SELECT '%' RLIKE '\\W';
SELECT '%a$' RLIKE '\\W.\\W';

SELECT '123' RLIKE '\\d\\d\\d';
SELECT 'aaa' RLIKE '\\d\\d\\d';
SELECT '1a3' RLIKE '\\d.\\d';
SELECT 'a1b' RLIKE '\\d.\\d';

SELECT '8' RLIKE '\\D';
SELECT 'a' RLIKE '\\D';
SELECT '%' RLIKE '\\D';
SELECT 'a1' RLIKE '\\D\\d';
SELECT 'a1' RLIKE '\\d\\D';

SELECT '\t' RLIKE '\\s'; 
SELECT '\r' RLIKE '\\s';
SELECT '\n' RLIKE '\\s';
SELECT '\v' RLIKE '\\s';

SELECT 'a' RLIKE '\\S';
SELECT '1' RLIKE '\\S';
SELECT '!' RLIKE '\\S';
SELECT '.' RLIKE '\\S';

# checking 0x00 bytes
# Bug#70470 REGEXP fails to find matches after NUL character
SELECT 'abc\0def' REGEXP 'def';
SELECT 'abc\0def' REGEXP 'abc\\x{00}def';
SELECT HEX(REGEXP_SUBSTR('abc\0def','abc\\x{00}def'));


--echo #
--echo # Checking REGEXP_REPLACE
--echo #

# Check data type
CREATE TABLE t1 AS SELECT REGEXP_REPLACE('abc','b','x');
SHOW CREATE TABLE t1;
DROP TABLE t1;

# Check print()
EXPLAIN EXTENDED SELECT REGEXP_REPLACE('abc','b','x');

# Check decimals
SET STATEMENT sql_mode = 'NO_ENGINE_SUBSTITUTION' FOR
CREATE TABLE t1 AS SELECT REGEXP_REPLACE('abc','b','x')+0;
SHOW CREATE TABLE t1;
DROP TABLE t1;

# Return NULL if any of the arguments are NULL
SELECT REGEXP_REPLACE(NULL,'b','c');
SELECT REGEXP_REPLACE('a',NULL,'c');
SELECT REGEXP_REPLACE('a','b',NULL);

# Return the original string if no match
SELECT REGEXP_REPLACE('a','x','b');

# Return the original string for an empty pattern
SELECT REGEXP_REPLACE('a','','b');

# Check that replace stops on the first empty match
# 'a5b' matches the pattern and '5' is replaced to 'x'
# then 'ab' matches the pattern, but the match '5*' is empty,
# so replacing stops here.
SELECT REGEXP_REPLACE('a5b ab a5b','(?<=a)5*(?=b)','x');

# A modified version of the previous example,
# to check that all matches are replaced if no empty match is met.
SELECT REGEXP_REPLACE('a5b a5b a5b','(?<=a)5*(?=b)','x');


# Check that case sensitiviry respects the collation
SELECT REGEXP_REPLACE('A','a','b');
SELECT REGEXP_REPLACE('a','A','b');
SELECT REGEXP_REPLACE('A' COLLATE utf8_bin,'a','b');
SELECT REGEXP_REPLACE('a' COLLATE utf8_bin,'A','b');

# Pattern references in the "replace" string
SELECT REGEXP_REPLACE('James Bond', '(.*) (.*)', '\\2, \\1 \\2');

# Checking with UTF8
SELECT REGEXP_REPLACE('абвгд','в','ц');

# Check that it does not treat binary strings as UTF8
SELECT REGEXP_REPLACE('г',0xB3,0xB4);

# Check that it replaces all matches by default
SELECT REGEXP_REPLACE('aaaa','a','b');

# Replace all matches except the first letter
SELECT REGEXP_REPLACE('aaaa','(?<=.)a','b');

# Replace all matches except the last letter
SELECT REGEXP_REPLACE('aaaa','a(?=.)','b');

# Replace all matches except the first and the last letter
SELECT REGEXP_REPLACE('aaaa','(?<=.)a(?=.)','b');

# newline character
SELECT REGEXP_REPLACE('a\nb','(*LF)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\nb','(*CR)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\nb','(*CRLF)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\nb','(*ANYCRLF)(?m)^a$','c');

SELECT REGEXP_REPLACE('a\rb','(*LF)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\rb','(*CR)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\rb','(*CRLF)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\rb','(*ANYCRLF)(?m)^a$','c');

SELECT REGEXP_REPLACE('a\r\nb','(*LF)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\r\nb','(*CR)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\r\nb','(*CRLF)(?m)^a$','c');
SELECT REGEXP_REPLACE('a\r\nb','(*ANYCRLF)(?m)^a$','c');

#backreference
SELECT REGEXP_REPLACE('aa','(a)\\g1','b');
SELECT REGEXP_REPLACE('aa bb','(a)\\g1 (b)\\g2','c');

#repitition
SELECT REGEXP_REPLACE('aaaaa','a{1,3}','b');
SELECT REGEXP_REPLACE('aaaaa','a{10,20}','b');

#Recursion
SELECT REGEXP_REPLACE('daabbd','a(?R)?b','c');
SELECT REGEXP_REPLACE('daabbd','aa(?R)?bb','c');

#Atomic grouping
SELECT REGEXP_REPLACE('dabccd','a(?>bc|b)c','e');
SELECT REGEXP_REPLACE('dabcd','a(?>bc|b)c','e');

#lookahead - negative
SELECT REGEXP_REPLACE('ab','a(?!b)','e');
SELECT REGEXP_REPLACE('ac','a(?!b)','e');

#lookahead - positive
SELECT REGEXP_REPLACE('ab','a(?=b)','e');
SELECT REGEXP_REPLACE('ac','a(?=b)','e');

#lookbehind - negative
SELECT REGEXP_REPLACE('ab','(?<!a)b','e');
SELECT REGEXP_REPLACE('cb','(?<!a)b','e');

#lookbehind - positive
SELECT REGEXP_REPLACE('ab','(?<=a)b','e');
SELECT REGEXP_REPLACE('cb','(?<=a)b','e');

# named subpatterns
SELECT REGEXP_REPLACE('aa','(?P<pattern>a)(?P=pattern)','b');
SELECT REGEXP_REPLACE('aba','(?P<pattern>a)b(?P=pattern)','c');

#comments
SELECT REGEXP_REPLACE('a','a(?#comment)','e');
SELECT REGEXP_REPLACE('aa','a(?#comment)a','e');
SELECT REGEXP_REPLACE('aba','a(?#b)a','e');

#ungreedy maching
SELECT REGEXP_REPLACE('ddd<ab>cc</ab>eee','<.+?>','*');

#Extended character classes 
SELECT REGEXP_REPLACE('aaa','\\W\\W\\W','e');
SELECT REGEXP_REPLACE('aaa','\\w\\w\\w','e');
SELECT REGEXP_REPLACE('%','\\W','e');
SELECT REGEXP_REPLACE('%a$','\\W.\\W','e');
SELECT REGEXP_REPLACE('%a$','\\W\\w\\W','e');

SELECT REGEXP_REPLACE('123','\\d\\d\\d\\d\\d\\d','e');
SELECT REGEXP_REPLACE('123','\\d\\d\\d','e');
SELECT REGEXP_REPLACE('aaa','\\d\\d\\d','e');
SELECT REGEXP_REPLACE('1a3','\\d.\\d\\d.\\d','e');
SELECT REGEXP_REPLACE('1a3','\\d.\\d','e');
SELECT REGEXP_REPLACE('a1b','\\d.\\d','e');

SELECT REGEXP_REPLACE('8','\\D','e');
SELECT REGEXP_REPLACE('a','\\D','e');
SELECT REGEXP_REPLACE('%','\\D','e');
SELECT REGEXP_REPLACE('a1','\\D\\d','e');
SELECT REGEXP_REPLACE('a1','\\d\\D','e');

SELECT REGEXP_REPLACE('\t','\\s','e');
SELECT REGEXP_REPLACE('\r','\\s','e');
SELECT REGEXP_REPLACE('\n','\\s','e');

SELECT REGEXP_REPLACE('a','\\S','e');
SELECT REGEXP_REPLACE('1','\\S','e');
SELECT REGEXP_REPLACE('!','\\S','e');
SELECT REGEXP_REPLACE('.','\\S','e');

--echo #
--echo # Checking REGEXP_INSTR
--echo #
SELECT REGEXP_INSTR('abcd','X');
SELECT REGEXP_INSTR('abcd','a');
SELECT REGEXP_INSTR('abcd','b');
SELECT REGEXP_INSTR('abcd','c');
SELECT REGEXP_INSTR('abcd','d');
SELECT REGEXP_INSTR('aaaa','(?<=a)a');

SELECT REGEXP_INSTR('вася','в');
SELECT REGEXP_INSTR('вася','а');
SELECT REGEXP_INSTR('вася','с');
SELECT REGEXP_INSTR('вася','я');
SELECT REGEXP_INSTR(CONVERT('вася' USING koi8r), CONVERT('в' USING koi8r));
SELECT REGEXP_INSTR(CONVERT('вася' USING koi8r), CONVERT('а' USING koi8r));
SELECT REGEXP_INSTR(CONVERT('вася' USING koi8r), CONVERT('с' USING koi8r));
SELECT REGEXP_INSTR(CONVERT('вася' USING koi8r), CONVERT('я' USING koi8r));


--echo #
--echo # Checking REGEXP_SUBSTR
--echo #

# Check data type
CREATE TABLE t1 AS SELECT REGEXP_SUBSTR('abc','b');
SHOW CREATE TABLE t1;
DROP TABLE t1;

# Check print()
EXPLAIN EXTENDED SELECT REGEXP_SUBSTR('abc','b');

# Check decimals
SET STATEMENT sql_mode = 'NO_ENGINE_SUBSTITUTION' FOR
CREATE TABLE t1 AS SELECT REGEXP_SUBSTR('abc','b')+0;
SHOW CREATE TABLE t1;
DROP TABLE t1;


SELECT REGEXP_SUBSTR('See https://mariadb.org/en/foundation/ for details', 'https?://[^/]*');


--echo #
--echo # MDEV-6027 RLIKE: "." no longer matching new line
--echo #
SELECT  'cat and\ndog'  RLIKE 'cat.*dog';
SELECT  'cat and\r\ndog'  RLIKE 'cat.*dog';
SELECT 'a\nb' RLIKE 'a.b';
SELECT 'a\nb' RLIKE '(?-s)a.b';
SET default_regex_flags='DOTALL';
SELECT @@default_regex_flags;
SELECT  'cat and\ndog'  RLIKE 'cat.*dog';
SELECT  'cat and\r\ndog'  RLIKE 'cat.*dog';
SELECT 'a\nb' RLIKE 'a.b';
SELECT 'a\nb' RLIKE '(?-s)a.b';
SET default_regex_flags=DEFAULT;

--error ER_REGEXP_ERROR
SELECT REGEXP_SUBSTR('Monday Mon','^((?<DN>Mon|Fri|Sun)day|(?<DN>Tue)sday).*(?P=DN)$');
SET default_regex_flags='DUPNAMES';
SELECT REGEXP_SUBSTR('Monday Mon','^((?<DN>Mon|Fri|Sun)day|(?<DN>Tue)sday).*(?P=DN)$');
SELECT REGEXP_SUBSTR('Tuesday Tue','^((?<DN>Mon|Fri|Sun)day|(?<DN>Tue)sday).*(?P=DN)$');
SET default_regex_flags=DEFAULT;

SELECT 'AB' RLIKE 'A B';
SELECT 'AB' RLIKE 'A# this is a comment\nB';
SET default_regex_flags='EXTENDED';
SELECT 'AB' RLIKE 'A B';
SELECT 'AB' RLIKE 'A# this is a comment\nB';
SET default_regex_flags=DEFAULT;

SELECT 'Aq' RLIKE 'A\\q';
SET default_regex_flags='EXTRA';
--error ER_REGEXP_ERROR
SELECT 'Aq' RLIKE 'A\\q';
SET default_regex_flags=DEFAULT;

SELECT 'a\nb\nc' RLIKE '^b$';
SET default_regex_flags='MULTILINE';
SELECT 'a\nb\nc' RLIKE '^b$';
SET default_regex_flags=DEFAULT;

SELECT REGEXP_SUBSTR('abc','.+');
SELECT REGEXP_REPLACE('abc','^(.*)(.*)$','\\1/\\2');
SET default_regex_flags='UNGREEDY';
SELECT REGEXP_SUBSTR('abc','.+');
SELECT REGEXP_REPLACE('abc','^(.*)(.*)$','\\1/\\2');
SET default_regex_flags=DEFAULT;

--echo #
--echo # MDEV-6965 non-captured group \2 in regexp_replace
--echo #
SELECT REGEXP_REPLACE('1 foo and bar', '(\\d+) foo and (\\d+ )?bar', '\\1 this and \\2that');

--echo #
--echo # MDEV-8102 REGEXP function fails to match hex values when expression is stored as a variable
--echo #

--echo # Testing a warning
SET NAMES latin1;
SET @regCheck= '\\xE0\\x01';
SELECT 0xE001 REGEXP @regCheck;

--echo # Testing workaround N1: This makes the pattern to be a binary string:
SET NAMES latin1;
SET @regCheck= X'E001';
SELECT 0xE001 REGEXP @regCheck;

--echo # Testing workaround N2: This also makes the pattern to be a binary string, using a different syntax:
SET NAMES latin1;
SET @regCheck= _binary '\\xE0\\x01';
SELECT 0xE001 REGEXP @regCheck;

--echo # Testing workarond N3: This makes derivation of the subject string stronger (IMLICIT instead of COERCIBLE)
SET NAMES latin1;
SET @regCheck= '\\xE0\\x01';
SELECT CAST(0xE001 AS BINARY) REGEXP @regCheck;

--echo # MDEV-12420: Testing recursion overflow
--replace_regex /[0-9]+ exceeded/NUM exceeded/
SELECT 1 FROM dual WHERE ('Alpha,Bravo,Charlie,Delta,Echo,Foxtrot,StrataCentral,Golf,Hotel,India,Juliet,Kilo,Lima,Mike,StrataL3,November,Oscar,StrataL2,Sand,P3,P4SwitchTest,Arsys,Poppa,ExtensionMgr,Arp,Quebec,Romeo,StrataApiV2,PtReyes,Sierra,SandAcl,Arrow,Artools,BridgeTest,Tango,SandT,PAlaska,Namespace,Agent,Qos,PatchPanel,ProjectReport,Ark,Gimp,Agent,SliceAgent,Arnet,Bgp,Ale,Tommy,Central,AsicPktTestLib,Hsc,SandL3,Abuild,Pca9555,Standby,ControllerDut,CalSys,SandLib,Sb820,PointV2,BfnLib,Evpn,BfnSdk,Sflow,ManagementActive,AutoTest,GatedTest,Bgp,Sand,xinetd,BfnAgentLib,bf-utils,Hello,BfnState,Eos,Artest,Qos,Scd,ThermoMgr,Uniform,EosUtils,Eb,FanController,Central,BfnL3,BfnL2,tcp_wrappers,Victor,Environment,Route,Failover,Whiskey,Xray,Gimp,BfnFixed,Strata,SoCal,XApi,Msrp,XpProfile,tcpdump,PatchPanel,ArosTest,FhTest,Arbus,XpAcl,MacConc,XpApi,telnet,QosTest,Alpha2,BfnVlan,Stp,VxlanControllerTest,MplsAgent,Bravo2,Lanz,BfnMbb,Intf,XCtrl,Unicast,SandTunnel,L3Unicast,Ipsec,MplsTest,Rsvp,EthIntf,StageMgr,Sol,MplsUtils,Nat,Ira,P4NamespaceDut,Counters,Charlie2,Aqlc,Mlag,Power,OpenFlow,Lag,RestApi,BfdTest,strongs,Sfa,CEosUtils,Adt746,MaintenanceMode,MlagDut,EosImage,IpEth,MultiProtocol,Launcher,Max3179,Snmp,Acl,IpEthTest,PhyEee,bf-syslibs,tacc,XpL2,p4-ar-switch,p4-bf-switch,LdpTest,BfnPhy,Mirroring,Phy6,Ptp'  REGEXP '^((?!\b(Strata|StrataApi|StrataApiV2)\b).)*$');

#
# MDEV-13173 An RLIKE that previously worked on 10.0 now returns "Got error 'pcre_exec: recursion limit of 100 exceeded' from regexp"
#
SELECT CONCAT(REPEAT('100,',60),'101') RLIKE '^(([1-9][0-9]*),)*[1-9][0-9]*$';
--replace_regex /[0-9]+ exceeded/NUM exceeded/
SELECT CONCAT(REPEAT('100,',200),'101') RLIKE '^(([1-9][0-9]*),)*[1-9][0-9]*$';

SELECT REGEXP_INSTR(CONCAT(REPEAT('100,',60),'101'), '^(([1-9][0-9]*),)*[1-9][0-9]*$');
--replace_regex /[0-9]+ exceeded/NUM exceeded/
SELECT REGEXP_INSTR(CONCAT(REPEAT('100,',200),'101'), '^(([1-9][0-9]*),)*[1-9][0-9]*$');

SELECT LENGTH(REGEXP_SUBSTR(CONCAT(REPEAT('100,',60),'101'), '^(([1-9][0-9]*),)*[1-9][0-9]*$'));
--replace_regex /[0-9]+ exceeded/NUM exceeded/
SELECT LENGTH(REGEXP_SUBSTR(CONCAT(REPEAT('100,',200),'101'), '^(([1-9][0-9]*),)*[1-9][0-9]*$'));

SELECT LENGTH(REGEXP_REPLACE(CONCAT(REPEAT('100,',60),'101'), '^(([1-9][0-9]*),)*[1-9][0-9]*$', ''));
--replace_regex /[0-9]+ exceeded/NUM exceeded/
SELECT LENGTH(REGEXP_REPLACE(CONCAT(REPEAT('100,',200),'101'), '^(([1-9][0-9]*),)*[1-9][0-9]*$', ''));

#
# MDEV-12942 REGEXP_INSTR returns 1 when using brackets
#
SELECT REGEXP_INSTR('a_kollision', 'oll');
SELECT REGEXP_INSTR('a_kollision', '(oll)');
SELECT REGEXP_INSTR('a_kollision', 'o([lm])\\1');

#
# MDEV-12939 A query crashes MariaDB in Item_func_regex::cleanup
#
SELECT a FROM (SELECT "aa" a) t WHERE a REGEXP '[0-9]';