MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8

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.

6 files changed, 376 insertions, 0 deletions

diff --git a/mysql-test/main/ctype_ldml.result b/mysql-test/main/ctype_ldml.result
index efafa9dc041..a23e835d1fa 100644
--- a/mysql-test/main/ctype_ldml.result
+++ b/mysql-test/main/ctype_ldml.result
@@ -3068,6 +3068,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -3081,6 +3087,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 #
 # End of 10.3 tests
@@ -3230,5 +3240,51 @@ is_520	0
 is_1400	1
 DROP TABLE t1;
 #
+# MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8
+#
+SET NAMES utf8mb4 COLLATE utf8mb4_uca1400_test01_as_ci;
+CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_uca1400_test01_as_ci DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+INSERT INTO case_folding (code) VALUES
+(0x23A),
+(0x23E),
+(0x23F),
+(0x240),
+(0x250),
+(0x251),
+(0x252),
+(0x26B),
+(0x271),
+(0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
+UPDATE case_folding SET c=CHAR(code USING ucs2);
+SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
+HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
+23A	E2B1A5	C8BA	Ⱥ
+23E	E2B1A6	C8BE	Ⱦ
+23F	C8BF	E2B1BE	ȿ
+240	C980	E2B1BF	ɀ
+250	C990	E2B1AF	ɐ
+251	C991	E2B1AD	ɑ
+252	C992	E2B1B0	ɒ
+26B	C9AB	E2B1A2	ɫ
+271	C9B1	E2B1AE	ɱ
+27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
+DROP TABLE case_folding;
+#
 # End of 10.10 tests
 #
diff --git a/mysql-test/main/ctype_ldml.test b/mysql-test/main/ctype_ldml.test
index 5ee56c3b950..6336a1d0f5f 100644
--- a/mysql-test/main/ctype_ldml.test
+++ b/mysql-test/main/ctype_ldml.test
@@ -698,5 +698,12 @@ ORDER BY a, HEX(a);
 DROP TABLE t1;
 
 --echo #
+--echo # MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8
+--echo #
+
+SET NAMES utf8mb4 COLLATE utf8mb4_uca1400_test01_as_ci;
+--source include/ctype_casefolding.inc
+
+--echo #
 --echo # End of 10.10 tests
 --echo #
diff --git a/mysql-test/main/ctype_utf8_uca.result b/mysql-test/main/ctype_utf8_uca.result
index e31acf8edc4..ecd2daa5272 100644
--- a/mysql-test/main/ctype_utf8_uca.result
+++ b/mysql-test/main/ctype_utf8_uca.result
@@ -612,6 +612,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -625,6 +631,53 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	C9AB	ɫ
 271	C9B1	C9B1	ɱ
 27D	C9BD	C9BD	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
+DROP TABLE case_folding;
+SET NAMES utf8mb3 COLLATE utf8mb3_turkish_ci /*Unicode-4.0 folding, with Turkish mapping for I */;
+CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_turkish_ci DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+INSERT INTO case_folding (code) VALUES
+(0x23A),
+(0x23E),
+(0x23F),
+(0x240),
+(0x250),
+(0x251),
+(0x252),
+(0x26B),
+(0x271),
+(0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
+UPDATE case_folding SET c=CHAR(code USING ucs2);
+SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
+HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
+23A	C8BA	C8BA	Ⱥ
+23E	C8BE	C8BE	Ⱦ
+23F	C8BF	C8BF	ȿ
+240	C980	C980	ɀ
+250	C990	C990	ɐ
+251	C991	C991	ɑ
+252	C992	C992	ɒ
+26B	C9AB	C9AB	ɫ
+271	C9B1	C9B1	ɱ
+27D	C9BD	C9BD	ɽ
+49	C4B1	49	I
+69	69	C4B0	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb3 COLLATE utf8mb3_unicode_520_ci;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -645,6 +698,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -658,6 +717,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb3 COLLATE utf8mb3_unicode_520_nopad_ci;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -678,6 +741,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -691,6 +760,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb3 COLLATE utf8mb3_myanmar_ci;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -711,6 +784,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -724,6 +803,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb3 COLLATE utf8mb3_thai_520_w2;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -744,6 +827,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -757,6 +846,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 #
 # End of 10.3 tests
@@ -1533,3 +1626,55 @@ SET NAMES utf8mb3;
 #
 # End of 10.10 tests
 #
+#
+# Start of 10.10 tests
+#
+#
+# MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8
+#
+SET NAMES utf8mb3 COLLATE utf8mb3_uca1400_ai_ci;
+CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_uca1400_ai_ci DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+INSERT INTO case_folding (code) VALUES
+(0x23A),
+(0x23E),
+(0x23F),
+(0x240),
+(0x250),
+(0x251),
+(0x252),
+(0x26B),
+(0x271),
+(0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
+UPDATE case_folding SET c=CHAR(code USING ucs2);
+SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
+HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
+23A	E2B1A5	C8BA	Ⱥ
+23E	E2B1A6	C8BE	Ⱦ
+23F	C8BF	E2B1BE	ȿ
+240	C980	E2B1BF	ɀ
+250	C990	E2B1AF	ɐ
+251	C991	E2B1AD	ɑ
+252	C992	E2B1B0	ɒ
+26B	C9AB	E2B1A2	ɫ
+271	C9B1	E2B1AE	ɱ
+27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
+DROP TABLE case_folding;
+#
+# End of 10.10 tests
+#
diff --git a/mysql-test/main/ctype_utf8_uca.test b/mysql-test/main/ctype_utf8_uca.test
index 946649417ae..5abf9192511 100644
--- a/mysql-test/main/ctype_utf8_uca.test
+++ b/mysql-test/main/ctype_utf8_uca.test
@@ -34,6 +34,9 @@ SET NAMES utf8 COLLATE utf8_unicode_nopad_ci;
 SET NAMES utf8mb3 COLLATE utf8mb3_unicode_ci /*Unicode-4.0 folding*/;
 --source include/ctype_casefolding.inc
 
+SET NAMES utf8mb3 COLLATE utf8mb3_turkish_ci /*Unicode-4.0 folding, with Turkish mapping for I */;
+--source include/ctype_casefolding.inc
+
 SET NAMES utf8mb3 COLLATE utf8mb3_unicode_520_ci;
 --source include/ctype_casefolding.inc
 
@@ -79,3 +82,19 @@ SET NAMES utf8mb3;
 --echo #
 --echo # End of 10.10 tests
 --echo #
+
+
+--echo #
+--echo # Start of 10.10 tests
+--echo #
+
+--echo #
+--echo # MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8
+--echo #
+
+SET NAMES utf8mb3 COLLATE utf8mb3_uca1400_ai_ci;
+--source include/ctype_casefolding.inc
+
+--echo #
+--echo # End of 10.10 tests
+--echo #
diff --git a/mysql-test/main/ctype_utf8mb4_uca.result b/mysql-test/main/ctype_utf8mb4_uca.result
index 195c47e0360..42de45c98a3 100644
--- a/mysql-test/main/ctype_utf8mb4_uca.result
+++ b/mysql-test/main/ctype_utf8mb4_uca.result
@@ -6630,6 +6630,55 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
+UPDATE case_folding SET c=CHAR(code USING ucs2);
+SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
+HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
+23A	C8BA	C8BA	Ⱥ
+23E	C8BE	C8BE	Ⱦ
+23F	C8BF	C8BF	ȿ
+240	C980	C980	ɀ
+250	C990	C990	ɐ
+251	C991	C991	ɑ
+252	C992	C992	ɒ
+26B	C9AB	C9AB	ɫ
+271	C9B1	C9B1	ɱ
+27D	C9BD	C9BD	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
+DROP TABLE case_folding;
+SET NAMES utf8mb4 COLLATE utf8mb4_turkish_ci /*Unicode-4.0 folding with Turkish mapping for I */;
+CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_turkish_ci DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+INSERT INTO case_folding (code) VALUES
+(0x23A),
+(0x23E),
+(0x23F),
+(0x240),
+(0x250),
+(0x251),
+(0x252),
+(0x26B),
+(0x271),
+(0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -6643,6 +6692,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	C9AB	ɫ
 271	C9B1	C9B1	ɱ
 27D	C9BD	C9BD	ɽ
+49	C4B1	49	I
+69	69	C4B0	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb4 COLLATE utf8mb4_unicode_520_ci;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -6663,6 +6716,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -6676,6 +6735,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb4 COLLATE utf8mb4_unicode_520_nopad_ci;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -6696,6 +6759,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -6709,6 +6778,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb4 COLLATE utf8mb4_myanmar_ci;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -6729,6 +6802,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -6742,6 +6821,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 SET NAMES utf8mb4 COLLATE utf8mb4_thai_520_w2;
 CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
@@ -6762,6 +6845,12 @@ INSERT INTO case_folding (code) VALUES
 (0x26B),
 (0x271),
 (0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
 UPDATE case_folding SET c=CHAR(code USING ucs2);
 SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
 HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
@@ -6775,6 +6864,10 @@ HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
 26B	C9AB	E2B1A2	ɫ
 271	C9B1	E2B1AE	ɱ
 27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
 DROP TABLE case_folding;
 #
 # End of 10.3 tests
@@ -11379,5 +11472,51 @@ DROP TABLE t1;
 DROP PROCEDURE exec_verbose;
 DROP PROCEDURE test_styles;
 #
+# MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8
+#
+SET NAMES utf8mb4 COLLATE utf8mb4_uca1400_ai_ci;
+CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_uca1400_ai_ci DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
+INSERT INTO case_folding (code) VALUES
+(0x23A),
+(0x23E),
+(0x23F),
+(0x240),
+(0x250),
+(0x251),
+(0x252),
+(0x26B),
+(0x271),
+(0x27D);
+INSERT INTO case_folding (code) VALUES
+(0x0049) /* LATIN CAPITAL LETTER I */,
+(0x0069) /* LATIN SMALL LETTER I */,
+(0x0130) /* LATIN CAPITAL LETTER I WITH DOT ABOVE */,
+(0x0131) /* LATIN SMALL LETTER DOTLESS I */
+;
+UPDATE case_folding SET c=CHAR(code USING ucs2);
+SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
+HEX(code)	HEX(LOWER(c))	HEX(UPPER(c))	c
+23A	E2B1A5	C8BA	Ⱥ
+23E	E2B1A6	C8BE	Ⱦ
+23F	C8BF	E2B1BE	ȿ
+240	C980	E2B1BF	ɀ
+250	C990	E2B1AF	ɐ
+251	C991	E2B1AD	ɑ
+252	C992	E2B1B0	ɒ
+26B	C9AB	E2B1A2	ɫ
+271	C9B1	E2B1AE	ɱ
+27D	C9BD	E2B1A4	ɽ
+49	69	49	I
+69	69	49	i
+130	69	C4B0	İ
+131	C4B1	49	ı
+DROP TABLE case_folding;
+#
 # End of 10.10 tests
 #
diff --git a/mysql-test/main/ctype_utf8mb4_uca.test b/mysql-test/main/ctype_utf8mb4_uca.test
index b4cfc910336..3f428447cc9 100644
--- a/mysql-test/main/ctype_utf8mb4_uca.test
+++ b/mysql-test/main/ctype_utf8mb4_uca.test
@@ -121,6 +121,9 @@ SET NAMES utf8mb4;
 SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci /*Unicode-4.0 folding*/;
 --source include/ctype_casefolding.inc
 
+SET NAMES utf8mb4 COLLATE utf8mb4_turkish_ci /*Unicode-4.0 folding with Turkish mapping for I */;
+--source include/ctype_casefolding.inc
+
 SET NAMES utf8mb4 COLLATE utf8mb4_unicode_520_ci;
 --source include/ctype_casefolding.inc
 
@@ -427,5 +430,12 @@ DROP PROCEDURE exec_verbose;
 DROP PROCEDURE test_styles;
 
 --echo #
+--echo # MDEV-30661 UPPER() returns an empty string for U+0251 in uca1400 collations for utf8
+--echo #
+
+SET NAMES utf8mb4 COLLATE utf8mb4_uca1400_ai_ci;
+--source include/ctype_casefolding.inc
+
+--echo #
 --echo # End of 10.10 tests
 --echo #