MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8

10 files changed, 517 insertions, 20 deletions

diff --git a/mysql-test/include/ctype_casefolding.inc b/mysql-test/include/ctype_casefolding.inc
new file mode 100644
index 00000000000..4ee402c95ad
--- /dev/null
+++ b/mysql-test/include/ctype_casefolding.inc
@@ -0,0 +1,18 @@
+CREATE OR REPLACE TABLE case_folding AS SELECT 0 AS code, SPACE(32) AS c LIMIT 0;
+SHOW CREATE TABLE case_folding;
+# Uncode code points that have a variable length case mapping in utf8
+# (e.g.  LOWER('2-byte-character') -> '3-byte-character'
+INSERT INTO case_folding (code) VALUES
+(0x23A),
+(0x23E),
+(0x23F),
+(0x240),
+(0x250),
+(0x251),
+(0x252),
+(0x26B),
+(0x271),
+(0x27D);
+UPDATE case_folding SET c=CHAR(code USING ucs2);
+SELECT HEX(code), HEX(LOWER(c)), HEX(UPPER(c)), c FROM case_folding;
+DROP TABLE case_folding;
diff --git a/mysql-test/main/ctype_ldml.result b/mysql-test/main/ctype_ldml.result
index 3ce50331ed0..ac1d66f3c91 100644
--- a/mysql-test/main/ctype_ldml.result
+++ b/mysql-test/main/ctype_ldml.result
@@ -3034,3 +3034,48 @@ SELECT 'chž'< 'i';
 1
 SELECT 'a' COLLATE utf8_czech_test_bad_w2;
 ERROR HY000: Unknown collation: 'utf8_czech_test_bad_w2'
+#
+# End of 10.2 tests
+#
+#
+# Start of 10.3 tests
+#
+#
+# MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8
+#
+SET NAMES utf8mb4 COLLATE utf8mb4_test_520_nopad_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_test_520_nopad_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);
+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
+DROP TABLE case_folding;
+#
+# End of 10.3 tests
+#
diff --git a/mysql-test/main/ctype_ldml.test b/mysql-test/main/ctype_ldml.test
index 68891646c0f..368e26dba20 100644
--- a/mysql-test/main/ctype_ldml.test
+++ b/mysql-test/main/ctype_ldml.test
@@ -605,3 +605,24 @@ SELECT 'chž'< 'i';
 
 --error ER_UNKNOWN_COLLATION
 SELECT 'a' COLLATE utf8_czech_test_bad_w2;
+
+--echo #
+--echo # End of 10.2 tests
+--echo #
+
+
+--echo #
+--echo # Start of 10.3 tests
+--echo #
+
+--echo #
+--echo # MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8
+--echo #
+
+SET NAMES utf8mb4 COLLATE utf8mb4_test_520_nopad_ci;
+--source include/ctype_casefolding.inc
+
+
+--echo #
+--echo # End of 10.3 tests
+--echo #
diff --git a/mysql-test/main/ctype_uca.result b/mysql-test/main/ctype_uca.result
index af2798f12f3..2298733851d 100644
--- a/mysql-test/main/ctype_uca.result
+++ b/mysql-test/main/ctype_uca.result
@@ -8204,7 +8204,7 @@ INSERT INTO t1 VALUES (_utf32 0x2CEE);
 SELECT hex(c), hex(lower(c)), hex(upper(c)), hex(weight_string(c)), c
 FROM t1 ORDER BY c, BINARY c;
 hex(c)	hex(lower(c))	hex(upper(c))	hex(weight_string(c))	c
-C8BA		C8BA	1214	Ⱥ
+C8BA	E2B1A5	C8BA	1214	Ⱥ
 E2B1A5	E2B1A5	C8BA	1214	ⱥ
 C680	C680	C983	122D	ƀ
 C983	C680	C983	122D	Ƀ
@@ -8229,7 +8229,7 @@ E2B1AA	E2B1AA	E2B1A9	1328	ⱪ
 C8BD	C69A	C8BD	133B	Ƚ
 E2B1A0	E2B1A1	E2B1A0	133F	Ⱡ
 E2B1A1	E2B1A1	E2B1A0	133F	ⱡ
-C9AB	C9AB		1340	ɫ
+C9AB	C9AB	E2B1A2	1340	ɫ
 E2B1A2	C9AB	E2B1A2	1340	Ɫ
 E1B5BD	E1B5BD	E2B1A3	13B8	ᵽ
 E2B1A3	E1B5BD	E2B1A3	13B8	Ᵽ
@@ -8237,11 +8237,11 @@ C98A	C98B	C98A	13D2	Ɋ
 C98B	C98B	C98A	13D2	ɋ
 C98C	C98D	C98C	13E4	Ɍ
 C98D	C98D	C98C	13E4	ɍ
-C9BD	C9BD		13FC	ɽ
+C9BD	C9BD	E2B1A4	13FC	ɽ
 E2B1A4	C9BD	E2B1A4	13FC	Ɽ
 EA9CA8	EA9CA9	EA9CA8	143314AD	Ꜩ
 EA9CA9	EA9CA9	EA9CA8	143314AD	ꜩ
-C8BE		C8BE	143C	Ⱦ
+C8BE	E2B1A6	C8BE	143C	Ⱦ
 E2B1A6	E2B1A6	C8BE	143C	ⱦ
 C984	CA89	C984	145B	Ʉ
 CA89	CA89	C984	145B	ʉ
diff --git a/mysql-test/main/ctype_utf8_uca.result b/mysql-test/main/ctype_utf8_uca.result
index a6e1616997f..bf4e5ed2fd8 100644
--- a/mysql-test/main/ctype_utf8_uca.result
+++ b/mysql-test/main/ctype_utf8_uca.result
@@ -587,3 +587,177 @@ DROP TABLE t1;
 #
 # End of 10.2 tests
 #
+#
+# Start of 10.3 tests
+#
+#
+# MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8
+#
+SET NAMES utf8mb3 COLLATE utf8mb3_unicode_ci /*Unicode-4.0 folding*/;
+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 utf8 COLLATE utf8_unicode_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);
+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
+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;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8 COLLATE utf8_unicode_520_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);
+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
+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;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8 COLLATE utf8_unicode_520_nopad_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);
+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
+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;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8 COLLATE utf8_myanmar_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);
+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
+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;
+SHOW CREATE TABLE case_folding;
+Table	Create Table
+case_folding	CREATE TABLE `case_folding` (
+  `code` int(1) NOT NULL,
+  `c` varchar(32) CHARACTER SET utf8 COLLATE utf8_thai_520_w2 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);
+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
+DROP TABLE case_folding;
+#
+# End of 10.3 tests
+#
diff --git a/mysql-test/main/ctype_utf8_uca.test b/mysql-test/main/ctype_utf8_uca.test
index 0879b4d2810..38bcce8f4ba 100644
--- a/mysql-test/main/ctype_utf8_uca.test
+++ b/mysql-test/main/ctype_utf8_uca.test
@@ -21,3 +21,32 @@ SET NAMES utf8 COLLATE utf8_unicode_nopad_ci;
 --echo #
 --echo # End of 10.2 tests
 --echo #
+
+
+--echo #
+--echo # Start of 10.3 tests
+--echo #
+
+--echo #
+--echo # MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8
+--echo #
+
+SET NAMES utf8mb3 COLLATE utf8mb3_unicode_ci /*Unicode-4.0 folding*/;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb3 COLLATE utf8mb3_unicode_520_ci;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb3 COLLATE utf8mb3_unicode_520_nopad_ci;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb3 COLLATE utf8mb3_myanmar_ci;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb3 COLLATE utf8mb3_thai_520_w2;
+--source include/ctype_casefolding.inc
+
+
+--echo #
+--echo # End of 10.3 tests
+--echo #
diff --git a/mysql-test/main/ctype_utf8mb4_uca.result b/mysql-test/main/ctype_utf8mb4_uca.result
index 8d2e81d8d89..d0a63d0dd36 100644
--- a/mysql-test/main/ctype_utf8mb4_uca.result
+++ b/mysql-test/main/ctype_utf8mb4_uca.result
@@ -6605,3 +6605,177 @@ SET NAMES utf8mb4;
 #
 # End of 10.2 tests
 #
+#
+# Start of 10.3 tests
+#
+#
+# MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8
+#
+SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci /*Unicode-4.0 folding*/;
+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_unicode_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);
+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
+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;
+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_unicode_520_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);
+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
+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;
+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_unicode_520_nopad_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);
+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
+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;
+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_myanmar_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);
+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
+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;
+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_thai_520_w2 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);
+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
+DROP TABLE case_folding;
+#
+# End of 10.3 tests
+#
diff --git a/mysql-test/main/ctype_utf8mb4_uca.test b/mysql-test/main/ctype_utf8mb4_uca.test
index 160cb48bad6..9b532f109d8 100644
--- a/mysql-test/main/ctype_utf8mb4_uca.test
+++ b/mysql-test/main/ctype_utf8mb4_uca.test
@@ -108,3 +108,32 @@ SET NAMES utf8mb4;
 --echo #
 --echo # End of 10.2 tests
 --echo #
+
+
+--echo #
+--echo # Start of 10.3 tests
+--echo #
+
+--echo #
+--echo # MDEV-30556 UPPER() returns an empty string for U+0251 in Unicode-5.2.0+ collations for utf8
+--echo #
+
+SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci /*Unicode-4.0 folding*/;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb4 COLLATE utf8mb4_unicode_520_ci;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb4 COLLATE utf8mb4_unicode_520_nopad_ci;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb4 COLLATE utf8mb4_myanmar_ci;
+--source include/ctype_casefolding.inc
+
+SET NAMES utf8mb4 COLLATE utf8mb4_thai_520_w2;
+--source include/ctype_casefolding.inc
+
+
+--echo #
+--echo # End of 10.3 tests
+--echo #
diff --git a/mysys/charset.c b/mysys/charset.c
index f44dc7606c1..c84039b0071 100644
--- a/mysys/charset.c
+++ b/mysys/charset.c
@@ -368,6 +368,8 @@ static int add_collation(struct charset_info_st *cs)
                                   &my_charset_utf8mb4_unicode_ci,
                                   cs);
         newcs->ctype= my_charset_utf8mb4_unicode_ci.ctype;
+        if (init_state_maps(newcs))
+          return MY_XML_ERROR;
         newcs->state|= MY_CS_AVAILABLE | MY_CS_LOADED;
 #endif
       }
diff --git a/strings/ctype-uca.c b/strings/ctype-uca.c
index fbca4df39e7..969f642b51f 100644
--- a/strings/ctype-uca.c
+++ b/strings/ctype-uca.c
@@ -33859,6 +33859,11 @@ create_tailoring(struct charset_info_st *cs,
   {
     src_uca= &my_uca_v520;
     cs->caseinfo= &my_unicase_unicode520;
+    if (cs->mbminlen == 1 && cs->mbmaxlen >=3)
+    {
+      cs->caseup_multiply= 2;
+      cs->casedn_multiply= 2;
+    }
   }
   else if (rules.version == 400)      /* Unicode-4.0.0 requested */
   {
@@ -35692,8 +35697,8 @@ struct charset_info_st my_charset_utf8_myanmar_uca_ci=
     NULL,                /* state_map    */
     NULL,                /* ident_map    */
     8,                   /* strxfrm_multiply */
-    1,                   /* caseup_multiply  */
-    1,                   /* casedn_multiply  */
+    2,                   /* caseup_multiply  */
+    2,                   /* casedn_multiply  */
     1,                   /* mbminlen     */
     3,                   /* mbmaxlen     */
     9,                   /* min_sort_char */
@@ -35725,8 +35730,8 @@ struct charset_info_st my_charset_utf8_unicode_520_ci=
     NULL,                /* state_map    */
     NULL,                /* ident_map    */
     8,                   /* strxfrm_multiply */
-    1,                   /* caseup_multiply  */
-    1,                   /* casedn_multiply  */
+    2,                   /* caseup_multiply  */
+    2,                   /* casedn_multiply  */
     1,                   /* mbminlen     */
     3,                   /* mbmaxlen     */
     9,                   /* min_sort_char */
@@ -35757,8 +35762,8 @@ struct charset_info_st my_charset_utf8_thai_520_w2=
     NULL,                /* state_map    */
     NULL,                /* ident_map    */
     4,                   /* strxfrm_multiply */
-    1,                   /* caseup_multiply  */
-    1,                   /* casedn_multiply  */
+    2,                   /* caseup_multiply  */
+    2,                   /* casedn_multiply  */
     1,                   /* mbminlen     */
     3,                   /* mbmaxlen     */
     9,                   /* min_sort_char */
@@ -35855,8 +35860,8 @@ struct charset_info_st my_charset_utf8_unicode_520_nopad_ci=
     NULL,                               /* state_map        */
     NULL,                               /* ident_map        */
     8,                                  /* strxfrm_multiply */
-    1,                                  /* caseup_multiply  */
-    1,                                  /* casedn_multiply  */
+    2,                                  /* caseup_multiply  */
+    2,                                  /* casedn_multiply  */
     1,                                  /* mbminlen         */
     3,                                  /* mbmaxlen         */
     9,                                  /* min_sort_char    */
@@ -36670,8 +36675,8 @@ struct charset_info_st my_charset_utf8mb4_myanmar_uca_ci=
     NULL,               /* state_map    */
     NULL,               /* ident_map    */
     8,                  /* strxfrm_multiply */
-    1,                  /* caseup_multiply  */
-    1,                  /* casedn_multiply  */
+    2,                  /* caseup_multiply  */
+    2,                  /* casedn_multiply  */
     1,                  /* mbminlen     */
     4,                  /* mbmaxlen     */
     9,                  /* min_sort_char */
@@ -36702,8 +36707,8 @@ struct charset_info_st my_charset_utf8mb4_thai_520_w2=
     NULL,                /* state_map    */
     NULL,                /* ident_map    */
     4,                   /* strxfrm_multiply */
-    1,                   /* caseup_multiply  */
-    1,                   /* casedn_multiply  */
+    2,                   /* caseup_multiply  */
+    2,                   /* casedn_multiply  */
     1,                   /* mbminlen     */
     4,                   /* mbmaxlen     */
     9,                   /* min_sort_char */
@@ -36734,8 +36739,8 @@ struct charset_info_st my_charset_utf8mb4_unicode_520_ci=
     NULL,                /* state_map    */
     NULL,                /* ident_map    */
     8,                   /* strxfrm_multiply */
-    1,                   /* caseup_multiply  */
-    1,                   /* casedn_multiply  */
+    2,                   /* caseup_multiply  */
+    2,                   /* casedn_multiply  */
     1,                   /* mbminlen     */
     4,                   /* mbmaxlen     */
     9,                   /* min_sort_char */
@@ -36833,8 +36838,8 @@ struct charset_info_st my_charset_utf8mb4_unicode_520_nopad_ci=
     NULL,                           /* state_map        */
     NULL,                           /* ident_map        */
     8,                              /* strxfrm_multiply */
-    1,                              /* caseup_multiply  */
-    1,                              /* casedn_multiply  */
+    2,                              /* caseup_multiply  */
+    2,                              /* casedn_multiply  */
     1,                              /* mbminlen         */
     4,                              /* mbmaxlen         */
     9,                              /* min_sort_char    */