diff --git a/mysql-test/suite/innodb/r/change_column_collation.result b/mysql-test/suite/innodb/r/change_column_collation.result
index fa1df1df830..54eff706276 100644
--- a/mysql-test/suite/innodb/r/change_column_collation.result
+++ b/mysql-test/suite/innodb/r/change_column_collation.result
@@ -9,11 +9,89 @@ msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_swedish_ci UNIQUE
 ) ENGINE=INNODB;
 INSERT INTO t1 VALUES (1, 'aaa');
 INSERT INTO t1 VALUES (2, 'ååå');
-ALTER TABLE t1
-MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci,
-ALGORITHM=NOCOPY;
-ERROR 0A000: ALGORITHM=NOCOPY is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-ALTER TABLE t1 DROP INDEX msg,
-MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci,
-ALGORITHM=NOCOPY;
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+ERROR 23000: Duplicate entry 'NULL' for key 'msg'
+DROP TABLE t1;
+CREATE TABLE t1 (
+id INT PRIMARY KEY,
+msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_bin,
+id_2 INT not null,
+unique index(msg, id_2)
+) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1, 'aaa', 2);
+INSERT INTO t1 VALUES (2, 'AAA', 3);
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+DROP TABLE t1;
+CREATE TABLE t1 (
+id INT PRIMARY KEY,
+msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_bin,
+unique index(msg)
+) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1, 'aaa');
+INSERT INTO t1 VALUES (2, 'bbb');
+INSERT INTO t1 VALUES (3, 'ccc');
+SET DEBUG_SYNC = 'RESET';
+SET DEBUG_SYNC = 'row_log_apply_before SIGNAL before_apply WAIT_FOR go_ahead';
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=NOCOPY;
+connect  con1,localhost,root,,;
+connection con1;
+SET DEBUG_SYNC = 'now WAIT_FOR before_apply';
+INSERT INTO t1 VALUES (4, 'AAA');
+UPDATE t1 set msg = "ddd" where id = 2;
+DELETE FROM t1 WHERE id= 3;
+SET DEBUG_SYNC = 'now SIGNAL go_ahead';
+SET DEBUG_SYNC = 'RESET';
+connection default;
+ERROR 23000: Duplicate entry 'NULL' for key 'msg'
+SELECT * FROM t1;
+id	msg
+4	AAA
+1	aaa
+2	ddd
+DROP TABLE t1;
+CREATE TABLE t1 (
+id INT PRIMARY KEY,
+msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_bin,
+unique index(msg)
+) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1, 'aaa');
+SET DEBUG_DBUG="+d,create_index_fail";
+SET DEBUG_SYNC="innodb_inplace_alter_table_enter SIGNAL con1_go WAIT_FOR alter_signal";
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=NOCOPY;
+connection con1;
+SET DEBUG_SYNC="now WAIT_FOR con1_go";
+BEGIN;
+SELECT * FROM t1;
+id	msg
+1	aaa
+SET DEBUG_SYNC="now SIGNAL alter_signal";
+connection default;
+ERROR 23000: Duplicate entry '' for key '*UNKNOWN*'
+connection con1;
+rollback;
+INSERT INTO t1 VALUES(2, 'bbb');
+disconnect con1;
+connection default;
+SET DEBUG_SYNC=reset;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL,
+  `msg` varchar(100) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL,
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `msg` (`msg`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+INSERT INTO t1 VALUES(3, 'ccc');
+DROP TABLE t1;
+CREATE TABLE t1(id INT PRIMARY KEY, msg VARCHAR(100),
+msg_1 VARCHAR(100) AS (msg) VIRTUAL,
+msg_2 VARCHAR(100) AS (msg) STORED,
+UNIQUE(msg), UNIQUE(msg_1),
+UNIQUE(msg_2))ENGINE=InnoDB;
+ALTER TABLE t1 MODIFY msg_1 VARCHAR(100) CHARACTER SET utf8
+COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+ERROR HY000: This is not yet supported for generated columns
+ALTER TABLE t1 MODIFY msg_2 VARCHAR(100) CHARACTER SET utf8
+COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+ERROR 0A000: ALGORITHM=INPLACE is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
 DROP TABLE t1;
diff --git a/mysql-test/suite/innodb/r/instant_alter_charset,redundant.rdiff b/mysql-test/suite/innodb/r/instant_alter_charset,redundant.rdiff
index dd4caf125af..90846ac4644 100644
--- a/mysql-test/suite/innodb/r/instant_alter_charset,redundant.rdiff
+++ b/mysql-test/suite/innodb/r/instant_alter_charset,redundant.rdiff
@@ -1,4 +1,4 @@
-@@ -288,7 +288,6 @@
+@@ -279,7 +279,6 @@
  alter table boundary_255
  modify a varchar(70) charset utf8mb4,
  algorithm=instant;
@@ -6,7 +6,7 @@
  drop table boundary_255;
  create table t (
  a char(10) collate utf8mb3_general_ci,
-@@ -306,35 +305,21 @@
+@@ -297,32 +296,21 @@
  repeat('a', 10), repeat('a', 10)
  );
  alter table t modify a char(10) collate utf8mb4_general_ci, algorithm=instant;
@@ -25,19 +25,16 @@
 -test.t	check	status	OK
 +ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
  alter table t modify aa char(10) collate utf8mb4_general_ci, algorithm=instant;
--ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
 -check table t;
 -Table	Op	Msg_type	Msg_text
 -test.t	check	status	OK
 +ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
  alter table t modify bb char(70) collate utf8mb4_general_ci, algorithm=instant;
--ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
 -check table t;
 -Table	Op	Msg_type	Msg_text
 -test.t	check	status	OK
 +ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
  alter table t modify cc char(100) collate utf8mb4_general_ci, algorithm=instant;
--ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
 -check table t;
 -Table	Op	Msg_type	Msg_text
 -test.t	check	status	OK
@@ -45,10 +42,17 @@
  alter table t modify d char(10) collate utf8mb4_spanish_ci, algorithm=instant;
 +ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
  alter table t modify dd char(10) collate utf8mb4_spanish_ci, algorithm=instant;
--ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 +ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
  select * from t;
  a	b	c	aa	bb	cc	d	dd
  aaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaa	aaaaaaaaaa
-
-mysqltest: Result length mismatch
+@@ -2066,7 +2054,7 @@
+ ALTER TABLE t1
+ CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci,
+ ADD UNIQUE INDEX test_key (a);
+-ERROR 23000: Duplicate entry 'NULL' for key 'test_key'
++ERROR 23000: Duplicate entry 'a1' for key 'test_key'
+ ALTER TABLE t1 CONVERT TO CHARACTER SET UTF8MB4 COLLATE UTF8MB4_UNICODE_520_CI;
+ CHECK TABLE t1;
+ Table	Op	Msg_type	Msg_text
diff --git a/mysql-test/suite/innodb/r/instant_alter_charset.result b/mysql-test/suite/innodb/r/instant_alter_charset.result
index f999697a329..caca0640566 100644
--- a/mysql-test/suite/innodb/r/instant_alter_charset.result
+++ b/mysql-test/suite/innodb/r/instant_alter_charset.result
@@ -199,15 +199,6 @@ a varchar(150) charset utf8mb3 unique key
 alter table key_part_bug
 modify a varchar(150) charset utf8mb4,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table key_part_bug
-modify a varchar(150) charset utf8mb4,
-algorithm=nocopy;
-ERROR 0A000: ALGORITHM=NOCOPY is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table key_part_bug
-drop index a,
-modify a varchar(150) charset utf8mb4,
-algorithm=nocopy;
 drop table key_part_bug;
 create table latin1_swedish_special_case (
 copy1 varchar(150) charset ascii collate ascii_general_ci,
@@ -318,23 +309,20 @@ check table t;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
 alter table t modify aa char(10) collate utf8mb4_general_ci, algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
 check table t;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
 alter table t modify bb char(70) collate utf8mb4_general_ci, algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
 check table t;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
 alter table t modify cc char(100) collate utf8mb4_general_ci, algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
 check table t;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
 alter table t modify d char(10) collate utf8mb4_spanish_ci, algorithm=instant;
 alter table t modify dd char(10) collate utf8mb4_spanish_ci, algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 select * from t;
 a	b	c	aa	bb	cc	d	dd
 aaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa	aaaaaaaaaa	aaaaaaaaaa
@@ -390,10 +378,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_general_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_general_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_general_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -407,10 +391,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_bin,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_bin,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_bin,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -424,10 +404,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_unicode_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -441,10 +417,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_icelandic_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_icelandic_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_icelandic_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -458,10 +430,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_latvian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_latvian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_latvian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -475,10 +443,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_romanian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_romanian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_romanian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -492,10 +456,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_slovenian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_slovenian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_slovenian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -509,10 +469,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_polish_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_polish_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_polish_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -526,10 +482,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_estonian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_estonian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_estonian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -543,10 +495,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_spanish_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_spanish_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_spanish_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -560,10 +508,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_swedish_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_swedish_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_swedish_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -577,10 +521,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_turkish_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_turkish_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_turkish_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -594,10 +534,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_czech_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_czech_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_czech_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -611,10 +547,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_danish_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_danish_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_danish_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -628,10 +560,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_lithuanian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_lithuanian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_lithuanian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -645,10 +573,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_slovak_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_slovak_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_slovak_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -662,10 +586,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_spanish2_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_spanish2_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_spanish2_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -679,10 +599,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_roman_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_roman_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_roman_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -696,10 +612,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_persian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_persian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_persian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -713,10 +625,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_esperanto_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_esperanto_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_esperanto_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -730,10 +638,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_hungarian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_hungarian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_hungarian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -747,10 +651,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_sinhala_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_sinhala_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_sinhala_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -764,10 +664,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_german2_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_german2_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_german2_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -781,10 +677,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_croatian_mysql561_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_croatian_mysql561_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_croatian_mysql561_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -798,10 +690,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_520_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_unicode_520_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_520_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -815,10 +703,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -832,10 +716,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_croatian_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_croatian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_croatian_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -849,10 +729,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_myanmar_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_myanmar_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_myanmar_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -866,10 +742,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_thai_520_w2,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_thai_520_w2,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_thai_520_w2,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -883,10 +755,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_general_nopad_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_general_nopad_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_general_nopad_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -900,10 +768,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_nopad_bin,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_nopad_bin,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_nopad_bin,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -917,10 +781,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_nopad_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_unicode_nopad_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_nopad_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -934,10 +794,6 @@ alter table tmp
 change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_520_nopad_ci,
 modify b varchar(50) charset utf8mb4 collate utf8mb4_unicode_520_nopad_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table tmp
-change a a varchar(50) charset utf8mb4 collate utf8mb4_unicode_520_nopad_ci,
-algorithm=instant;
 check table tmp;
 Table	Op	Msg_type	Msg_text
 test.tmp	check	status	OK
@@ -974,7 +830,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
@@ -991,7 +847,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
@@ -1008,7 +864,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
@@ -1025,7 +881,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb4 collate utf8mb4_vietnamese_ci,
 algorithm=instant;
@@ -1042,7 +898,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset ascii collate ascii_bin,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset ascii collate ascii_bin,
 algorithm=instant;
@@ -1059,7 +915,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb3 collate utf8mb3_lithuanian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb3 collate utf8mb3_lithuanian_ci,
 algorithm=instant;
@@ -1076,7 +932,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb4 collate utf8mb4_persian_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb4 collate utf8mb4_persian_ci,
 algorithm=instant;
@@ -1093,7 +949,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb4 collate utf8mb4_german2_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb4 collate utf8mb4_german2_ci,
 algorithm=instant;
@@ -1110,7 +966,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf8mb3 collate utf8mb3_unicode_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf8mb3 collate utf8mb3_unicode_ci,
 algorithm=instant;
@@ -1127,7 +983,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset latin1 collate latin1_general_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset latin1 collate latin1_general_ci,
 algorithm=instant;
@@ -1144,7 +1000,7 @@ algorithm=instant;
 alter table tmp
 modify b varchar(50) charset utf16 collate utf16_german2_ci,
 algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table tmp
 modify c varchar(50) charset utf16 collate utf16_german2_ci,
 algorithm=instant;
@@ -2031,11 +1887,8 @@ insert into t values
 alter table t modify a char(10) collate latin1_general_cs, algorithm=inplace;
 ERROR 0A000: ALGORITHM=INPLACE is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
 alter table t modify b char(10) collate latin1_general_cs, algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table t modify b char(10) collate latin1_general_cs, algorithm=nocopy;
-ERROR 0A000: ALGORITHM=NOCOPY is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table t modify b char(10) collate latin1_general_cs,
-drop index b_key, algorithm=nocopy;
 check table t;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
@@ -2055,11 +1908,8 @@ insert into t values
 alter table t modify a varchar(10) collate latin1_general_cs, algorithm=inplace;
 ERROR 0A000: ALGORITHM=INPLACE is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
 alter table t modify b varchar(10) collate latin1_general_cs, algorithm=instant;
-ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
+ERROR 0A000: ALGORITHM=INSTANT is not supported. Reason: ADD INDEX. Try ALGORITHM=NOCOPY
 alter table t modify b varchar(10) collate latin1_general_cs, algorithm=nocopy;
-ERROR 0A000: ALGORITHM=NOCOPY is not supported. Reason: Collation change on an indexed column. Try ALGORITHM=COPY
-alter table t modify b varchar(10) collate latin1_general_cs,
-drop index b_key, algorithm=nocopy;
 check table t;
 Table	Op	Msg_type	Msg_text
 test.t	check	status	OK
@@ -2201,7 +2051,7 @@ INSERT INTO t1 VALUES (1, 'a1'), (2, 'a1');
 ALTER TABLE t1
 CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci,
 ADD UNIQUE INDEX test_key (a);
-ERROR 23000: Duplicate entry 'a1' for key 'test_key'
+ERROR 23000: Duplicate entry 'NULL' for key 'test_key'
 ALTER TABLE t1 CONVERT TO CHARACTER SET UTF8MB4 COLLATE UTF8MB4_UNICODE_520_CI;
 CHECK TABLE t1;
 Table	Op	Msg_type	Msg_text
@@ -2216,7 +2066,7 @@ INSERT INTO t1 VALUES (1, 'a1'), (2, 'a1');
 ALTER TABLE t1
 CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci,
 ADD UNIQUE INDEX test_key (a);
-ERROR 23000: Duplicate entry 'a1' for key 'test_key'
+ERROR 23000: Duplicate entry 'NULL' for key 'test_key'
 ALTER TABLE t1 CONVERT TO CHARACTER SET UTF8MB4 COLLATE UTF8MB4_UNICODE_520_CI;
 CHECK TABLE t1;
 Table	Op	Msg_type	Msg_text
diff --git a/mysql-test/suite/innodb/t/change_column_collation.test b/mysql-test/suite/innodb/t/change_column_collation.test
index 1ba519535bd..7d82aac7ec2 100644
--- a/mysql-test/suite/innodb/t/change_column_collation.test
+++ b/mysql-test/suite/innodb/t/change_column_collation.test
@@ -1,4 +1,8 @@
 --source include/have_innodb.inc
+--source include/have_debug.inc
+--source include/have_debug_sync.inc
+
+--source include/count_sessions.inc
 
 --echo #
 --echo # MDEV-26294 Duplicate entries in unique index not detected when
@@ -14,11 +18,108 @@ CREATE TABLE t1 (
 ) ENGINE=INNODB;
 INSERT INTO t1 VALUES (1, 'aaa');
 INSERT INTO t1 VALUES (2, 'ååå');
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
-ALTER TABLE t1
-MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci,
-ALGORITHM=NOCOPY;
-ALTER TABLE t1 DROP INDEX msg,
-MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci,
-ALGORITHM=NOCOPY;
+--error ER_DUP_ENTRY
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=inplace;
 DROP TABLE t1;
+
+# PageBulk insert shouldn't fail like records are not in ascending order
+
+CREATE TABLE t1 (
+  id INT PRIMARY KEY,
+  msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_bin,
+  id_2 INT not null,
+  unique index(msg, id_2)
+) ENGINE=INNODB;
+
+INSERT INTO t1 VALUES (1, 'aaa', 2);
+INSERT INTO t1 VALUES (2, 'AAA', 3);
+
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+
+DROP TABLE t1;
+
+# Detect the duplicate entry from concurrent DML
+
+CREATE TABLE t1 (
+  id INT PRIMARY KEY,
+  msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_bin,
+  unique index(msg)
+) ENGINE=INNODB;
+
+INSERT INTO t1 VALUES (1, 'aaa');
+INSERT INTO t1 VALUES (2, 'bbb');
+INSERT INTO t1 VALUES (3, 'ccc');
+
+SET DEBUG_SYNC = 'RESET';
+SET DEBUG_SYNC = 'row_log_apply_before SIGNAL before_apply WAIT_FOR go_ahead';
+--send
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=NOCOPY;
+
+connect (con1,localhost,root,,);
+connection con1;
+
+SET DEBUG_SYNC = 'now WAIT_FOR before_apply';
+INSERT INTO t1 VALUES (4, 'AAA');
+UPDATE t1 set msg = "ddd" where id = 2;
+DELETE FROM t1 WHERE id= 3;
+SET DEBUG_SYNC = 'now SIGNAL go_ahead';
+SET DEBUG_SYNC = 'RESET';
+
+connection default;
+
+--error ER_DUP_ENTRY
+reap;
+
+SELECT * FROM t1;
+DROP TABLE t1;
+
+# InnoDB should store the changed collation column into
+# change_col_info in index when rollback of alter happens
+
+CREATE TABLE t1 (
+  id INT PRIMARY KEY,
+  msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_bin,
+  unique index(msg)
+) ENGINE=INNODB;
+
+INSERT INTO t1 VALUES (1, 'aaa');
+SET DEBUG_DBUG="+d,create_index_fail";
+SET DEBUG_SYNC="innodb_inplace_alter_table_enter SIGNAL con1_go WAIT_FOR alter_signal";
+--send
+ALTER TABLE t1 MODIFY msg VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci, ALGORITHM=NOCOPY;
+
+connection con1;
+SET DEBUG_SYNC="now WAIT_FOR con1_go";
+BEGIN;
+SELECT * FROM t1;
+SET DEBUG_SYNC="now SIGNAL alter_signal";
+connection default;
+--error ER_DUP_ENTRY
+reap;
+connection con1;
+rollback;
+INSERT INTO t1 VALUES(2, 'bbb');
+disconnect con1;
+connection default;
+SET DEBUG_SYNC=reset;
+SHOW CREATE TABLE t1;
+INSERT INTO t1 VALUES(3, 'ccc');
+DROP TABLE t1;
+
+# Inplace Collation change is not supported for virtual column
+# and stored column
+
+CREATE TABLE t1(id INT PRIMARY KEY, msg VARCHAR(100),
+		msg_1 VARCHAR(100) AS (msg) VIRTUAL,
+		msg_2 VARCHAR(100) AS (msg) STORED,
+		UNIQUE(msg), UNIQUE(msg_1),
+		UNIQUE(msg_2))ENGINE=InnoDB;
+--error ER_UNSUPPORTED_ACTION_ON_GENERATED_COLUMN
+ALTER TABLE t1 MODIFY msg_1 VARCHAR(100) CHARACTER SET utf8
+		COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
+ALTER TABLE t1 MODIFY msg_2 VARCHAR(100) CHARACTER SET utf8
+                COLLATE utf8_unicode_ci, ALGORITHM=inplace;
+DROP TABLE t1;
+
+--source include/wait_until_count_sessions.inc
diff --git a/mysql-test/suite/innodb/t/instant_alter_charset.test b/mysql-test/suite/innodb/t/instant_alter_charset.test
index f0366967ab8..5be4f7a5b83 100644
--- a/mysql-test/suite/innodb/t/instant_alter_charset.test
+++ b/mysql-test/suite/innodb/t/instant_alter_charset.test
@@ -227,18 +227,9 @@ create table key_part_bug (
   a varchar(150) charset utf8mb3 unique key
 ) engine=innodb;
 
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table key_part_bug
   modify a varchar(150) charset utf8mb4,
   algorithm=instant;
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
-alter table key_part_bug
-  modify a varchar(150) charset utf8mb4,
-  algorithm=nocopy;
-alter table key_part_bug
-  drop index a,
-  modify a varchar(150) charset utf8mb4,
-  algorithm=nocopy;
 
 drop table key_part_bug;
 
@@ -356,13 +347,10 @@ check table t;
 alter table t modify c char(100) collate utf8mb4_general_ci, algorithm=instant;
 check table t;
 
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify aa char(10) collate utf8mb4_general_ci, algorithm=instant;
 check table t;
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify bb char(70) collate utf8mb4_general_ci, algorithm=instant;
 check table t;
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify cc char(100) collate utf8mb4_general_ci, algorithm=instant;
 check table t;
 
@@ -454,16 +442,11 @@ while ($counter <= $data_size) {
 
   insert into tmp values ('AAA', 'AAA'), ('bbb', 'bbb');
 
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
   eval alter table tmp
     change a a varchar(50) charset $to_charset collate $to_collate,
     modify b varchar(50) charset $to_charset collate $to_collate,
     algorithm=instant;
 
-  eval alter table tmp
-    change a a varchar(50) charset $to_charset collate $to_collate,
-    algorithm=instant;
-
   check table tmp;
 
   drop table tmp;
@@ -702,10 +685,7 @@ alter table t modify a char(10) collate latin1_general_cs, algorithm=inplace;
 
 --error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify b char(10) collate latin1_general_cs, algorithm=instant;
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify b char(10) collate latin1_general_cs, algorithm=nocopy;
-alter table t modify b char(10) collate latin1_general_cs,
-drop index b_key, algorithm=nocopy;
 check table t;
 
 alter table t modify c char(10) collate latin1_general_cs, algorithm=instant;
@@ -728,10 +708,7 @@ alter table t modify a varchar(10) collate latin1_general_cs, algorithm=inplace;
 
 --error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify b varchar(10) collate latin1_general_cs, algorithm=instant;
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 alter table t modify b varchar(10) collate latin1_general_cs, algorithm=nocopy;
-alter table t modify b varchar(10) collate latin1_general_cs,
-drop index b_key, algorithm=nocopy;
 check table t;
 
 alter table t modify c varchar(10) collate latin1_general_cs, algorithm=instant;
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index fe9138c3ae7..b46d68aac63 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -956,6 +956,41 @@ get_error_key_name(
 	}
 }
 
+/** Convert field type and length to InnoDB format */
+static void get_type(const Field &f, uint &prtype, uint8_t &mtype,
+                     uint16_t &len)
+{
+  mtype= get_innobase_type_from_mysql_type(&prtype, &f);
+  len= static_cast<uint16_t>(f.pack_length());
+  prtype|= f.type();
+  if (f.type() == MYSQL_TYPE_VARCHAR)
+  {
+    auto l= static_cast<const Field_varstring&>(f).length_bytes;
+    len= static_cast<uint16_t>(len - l);
+    if (l == 2)
+      prtype|= DATA_LONG_TRUE_VARCHAR;
+  }
+  if (!f.real_maybe_null())
+    prtype |= DATA_NOT_NULL;
+  if (f.binary())
+    prtype |= DATA_BINARY_TYPE;
+  if (f.table->versioned())
+  {
+    if (&f == f.table->field[f.table->s->vers.start_fieldno])
+      prtype|= DATA_VERS_START;
+    else if (&f == f.table->field[f.table->s->vers.end_fieldno])
+      prtype|= DATA_VERS_END;
+    else if (!(f.flags & VERS_UPDATE_UNVERSIONED_FLAG))
+      prtype|= DATA_VERSIONED;
+  }
+
+  if (!f.stored_in_db())
+    prtype|= DATA_VIRTUAL;
+
+  if (dtype_is_string_type(mtype))
+    prtype|= f.charset()->number << 16;
+}
+
 struct ha_innobase_inplace_ctx : public inplace_alter_handler_ctx
 {
 	/** Dummy query graph */
@@ -1050,6 +1085,10 @@ struct ha_innobase_inplace_ctx : public inplace_alter_handler_ctx
 	/** The page_compression_level attribute, or 0 */
 	const uint	page_compression_level;
 
+	/** Indexed columns whose charset-collation is changing
+	in a way that does not require the table to be rebuilt */
+	col_collations change_col_collate;
+
 	ha_innobase_inplace_ctx(row_prebuilt_t*& prebuilt_arg,
 				dict_index_t** drop_arg,
 				ulint num_to_drop_arg,
@@ -1332,6 +1371,85 @@ struct ha_innobase_inplace_ctx : public inplace_alter_handler_ctx
     }
     return true;
   }
+
+  /** Check whether the column has any change in collation type.
+  If it is then store the column information in heap
+  @param index          index being added (or rebuilt)
+  @param altered_table  altered table definition */
+  void change_col_collation(dict_index_t *index, const TABLE &altered_table)
+  {
+    ut_ad(!need_rebuild());
+    ut_ad(!index->is_primary());
+    ut_ad(!index->is_committed());
+
+    unsigned n_cols= 0;
+    for (unsigned i= 0; i < index->n_fields; i++)
+    {
+      const char *field_name= index->fields[i].name();
+      if (!field_name || !dtype_is_string_type(index->fields[i].col->mtype))
+        continue;
+      for (uint j= 0; j < altered_table.s->fields; j++)
+      {
+        const Field *altered_field= altered_table.field[j];
+
+        if (my_strcasecmp(system_charset_info, field_name,
+                          altered_field->field_name.str))
+          continue;
+
+        unsigned prtype;
+        uint8_t mtype;
+        uint16_t len;
+        get_type(*altered_field, prtype, mtype, len);
+
+        if (prtype == index->fields[i].col->prtype)
+          continue;
+        auto it= change_col_collate.find(index->fields[i].col->ind);
+        if (it != change_col_collate.end())
+        {
+          n_cols++;
+          index->fields[i].col= it->second;
+          continue;
+        }
+
+        const CHARSET_INFO *cs= altered_field->charset();
+
+        dict_col_t *col=
+          static_cast<dict_col_t*>(mem_heap_alloc(heap, sizeof *col));
+        *col= *index->fields[i].col;
+        col->prtype= prtype;
+        col->mtype= mtype;
+        col->mbminlen= cs->mbminlen & 7;
+        col->mbmaxlen= cs->mbmaxlen & 7;
+        col->len= len;
+        index->fields[i].col= col;
+        n_cols++;
+        change_col_collate[col->ind]= col;
+      }
+    }
+
+    index->init_change_cols(n_cols);
+  }
+
+  void cleanup_col_collation()
+  {
+    ut_ad(old_table == new_table);
+    if (change_col_collate.empty())
+      return;
+    const dict_index_t *index= dict_table_get_first_index(old_table);
+    while ((index= dict_table_get_next_index(index)) != nullptr)
+    {
+      if (index->is_committed())
+        continue;
+      auto collate_end= change_col_collate.end();
+      for (unsigned i= 0, j= 0; i < index->n_fields; i++)
+      {
+        const dict_col_t *col= index->fields[i].col;
+        if (change_col_collate.find(col->ind) == collate_end)
+          index->fields[i].col=
+            index->change_col_info->add(index->heap, *col, j++);
+      }
+    }
+  }
 };
 
 /********************************************************************//**
@@ -2345,16 +2463,7 @@ innodb_instant_alter_column_allowed_reason:
 
 			if (new_field->field) {
 				/* This is an existing column. */
-
-				if (new_field->field->charset()
-				    == key_part->field->charset()) {
-					continue;
-				}
-
-				ha_alter_info->unsupported_reason =
-					"Collation change on"
-					" an indexed column";
-				DBUG_RETURN(HA_ALTER_INPLACE_NOT_SUPPORTED);
+				continue;
 			}
 
 			/* This is an added column. */
@@ -7061,6 +7170,8 @@ error_handling_drop_uncached:
 			if (n_v_col) {
 				index->assign_new_v_col(n_v_col);
 			}
+
+			ctx->change_col_collation(index, *altered_table);
 			/* Note the id of the transaction that created this
 			index, we use it to restrict readers from accessing
 			this index, to ensure read consistency. */
@@ -8533,7 +8644,9 @@ ok_exit:
 		ctx->add_index, ctx->add_key_numbers, ctx->num_to_add_index,
 		altered_table, ctx->defaults, ctx->col_map,
 		ctx->add_autoinc, ctx->sequence, ctx->skip_pk_sort,
-		ctx->m_stage, add_v, eval_table, ctx->allow_not_null);
+		ctx->m_stage, add_v, eval_table, ctx->allow_not_null,
+		ctx->change_col_collate.empty()
+		? nullptr : &ctx->change_col_collate);
 
 #ifndef DBUG_OFF
 oom:
@@ -8867,6 +8980,7 @@ inline bool rollback_inplace_alter_table(Alter_inplace_info *ha_alter_info,
                                   Alter_info::ALTER_TABLE_LOCK_EXCLUSIVE,
                                   ctx->trx, prebuilt->trx);
       ctx->clean_new_vcol_index();
+      ctx->cleanup_col_collation();
       ut_d(dict_table_check_for_dup_indexes(ctx->old_table, CHECK_ABORTED_OK));
     }
 
@@ -9265,36 +9379,6 @@ processed_field:
 	return(false);
 }
 
-/** Convert field type and length to InnoDB format */
-static void get_type(const Field& f, uint& prtype, uint8_t& mtype,
-                     uint16_t& len)
-{
-	mtype = get_innobase_type_from_mysql_type(&prtype, &f);
-	len = static_cast<uint16_t>(f.pack_length());
-	prtype |= f.type();
-	if (f.type() == MYSQL_TYPE_VARCHAR) {
-		auto l = static_cast<const Field_varstring&>(f).length_bytes;
-		len = static_cast<uint16_t>(len - l);
-		if (l == 2) prtype |= DATA_LONG_TRUE_VARCHAR;
-	}
-	if (!f.real_maybe_null()) prtype |= DATA_NOT_NULL;
-	if (f.binary()) prtype |= DATA_BINARY_TYPE;
-	if (f.table->versioned()) {
-		if (&f == f.table->field[f.table->s->vers.start_fieldno]) {
-			prtype |= DATA_VERS_START;
-		} else if (&f == f.table->field[f.table->s->vers.end_fieldno]) {
-			prtype |= DATA_VERS_END;
-		} else if (!(f.flags & VERS_UPDATE_UNVERSIONED_FLAG)) {
-			prtype |= DATA_VERSIONED;
-		}
-	}
-	if (!f.stored_in_db()) prtype |= DATA_VIRTUAL;
-
-	if (dtype_is_string_type(mtype)) {
-		prtype |= f.charset()->number << 16;
-	}
-}
-
 /** Enlarge a column in the data dictionary tables.
 @param ctx In-place ALTER TABLE context
 @param trx data dictionary transaction
@@ -10617,6 +10701,7 @@ commit_cache_norebuild(
 		DBUG_ASSERT(dict_index_get_online_status(index)
 			    == ONLINE_INDEX_COMPLETE);
 		DBUG_ASSERT(!index->is_committed());
+		index->change_col_info = nullptr;
 		index->set_committed(true);
 	}
 
@@ -11368,7 +11453,8 @@ foreign_fail:
 		    || ha_alter_info->alter_info->create_list.elements))
 	    || (ctx0->is_instant()
 		&& m_prebuilt->table->n_v_cols
-		&& ha_alter_info->handler_flags & ALTER_STORED_COLUMN_ORDER)) {
+		&& ha_alter_info->handler_flags & ALTER_STORED_COLUMN_ORDER)
+	    || !ctx0->change_col_collate.empty()) {
 		DBUG_ASSERT(ctx0->old_table->get_ref_count() == 1);
 		ut_ad(ctx0->prebuilt == m_prebuilt);
 
diff --git a/storage/innobase/include/data0data.h b/storage/innobase/include/data0data.h
index c2b8c3e00b6..5eaad5bf552 100644
--- a/storage/innobase/include/data0data.h
+++ b/storage/innobase/include/data0data.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2019, 2020 MariaDB Corporation.
+Copyright (c) 2017, 2022, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -581,6 +581,10 @@ struct dtuple_t {
 	/** @return whether this is a hidden metadata record
 	for instant ADD COLUMN or ALTER TABLE */
 	bool is_metadata() const { return is_metadata(info_bits); }
+
+	/** Copy type information from index fields.
+	@param index	index field to be copied */
+	inline void copy_field_types(const dict_index_t &index);
 };
 
 inline ulint dtuple_get_n_fields(const dtuple_t* tuple)
diff --git a/storage/innobase/include/data0type.h b/storage/innobase/include/data0type.h
index ae688bf85fe..3d63ddb767c 100644
--- a/storage/innobase/include/data0type.h
+++ b/storage/innobase/include/data0type.h
@@ -488,6 +488,8 @@ dtype_print(
 	const dtype_t*	type);
 #endif /* UNIV_DEBUG */
 
+struct dict_col_t;
+
 /* Structure for an SQL data type.
 If you add fields to this structure, be sure to initialize them everywhere.
 This structure is initialized in the following functions:
@@ -543,6 +545,10 @@ struct dtype_t{
 		mbminlen = 0;
 		mbmaxlen = 0;
 	}
+
+	/** Copy the type information from a column.
+	@param col column type to be copied */
+	void assign(const dict_col_t &col);
 };
 
 /** The DB_TRX_ID,DB_ROLL_PTR values for "no history is available" */
diff --git a/storage/innobase/include/dict0mem.h b/storage/innobase/include/dict0mem.h
index da96d07e260..bd8872019cb 100644
--- a/storage/innobase/include/dict0mem.h
+++ b/storage/innobase/include/dict0mem.h
@@ -966,6 +966,26 @@ const char innobase_index_reserve_name[] = "GEN_CLUST_INDEX";
 /** Data structure for an index.  Most fields will be
 initialized to 0, NULL or FALSE in dict_mem_index_create(). */
 struct dict_index_t {
+  /** Columns whose character-set collation is being changed */
+  struct col_info
+  {
+    /** number of columns whose charset-collation is being changed */
+    unsigned n_cols;
+    /** columns with changed charset-collation */
+    dict_col_t *cols;
+
+    /** Add a column with changed collation. */
+    dict_col_t *add(mem_heap_t *heap, const dict_col_t &col, unsigned offset)
+    {
+      ut_ad(offset < n_cols);
+      if (!cols)
+        cols= static_cast<dict_col_t*>
+          (mem_heap_alloc(heap, n_cols * sizeof col));
+      new (&cols[offset]) dict_col_t(col);
+      return &cols[offset];
+    }
+  };
+
   /** Maximum number of fields */
   static constexpr unsigned MAX_N_FIELDS= (1U << 10) - 1;
 
@@ -1051,6 +1071,16 @@ struct dict_index_t {
 	It should use heap from dict_index_t. It should be freed
 	while removing the index from table. */
 	dict_add_v_col_info* new_vcol_info;
+
+	/** During ALTER TABLE, columns that a being-added index depends on
+	and whose encoding or collation is being changed to something
+	that is compatible with the clustered index.
+	Allocated from dict_index_t::heap.
+
+	@see rollback_inplace_alter_table()
+	@see ha_innobase_inplace_ctx::col_collations */
+	col_info* change_col_info;
+
 	UT_LIST_NODE_T(dict_index_t)
 			indexes;/*!< list of indexes of the table */
 #ifdef BTR_CUR_ADAPT
@@ -1145,6 +1175,7 @@ public:
 	{
 		ut_ad(!to_be_dropped);
 		ut_ad(committed || !(type & DICT_CLUSTERED));
+		ut_ad(!committed || !change_col_info);
 		uncommitted = !committed;
 	}
 
@@ -1310,6 +1341,16 @@ public:
   ulint get_new_n_vcol() const
   { return new_vcol_info ? new_vcol_info->n_v_col : 0; }
 
+  /** Assign the number of collation change fields as a part of the index
+  @param  n_cols   number of columns whose collation is changing */
+  void init_change_cols(unsigned n_cols)
+  {
+    ut_ad(n_fields > n_cols);
+    change_col_info= static_cast<col_info*>
+      (mem_heap_zalloc(heap, sizeof(col_info)));
+    change_col_info->n_cols= n_cols;
+  }
+
   /** Reconstruct the clustered index fields.
   @return whether metadata is incorrect */
   inline bool reconstruct_fields();
diff --git a/storage/innobase/include/row0merge.h b/storage/innobase/include/row0merge.h
index e9e250435f0..52096d48313 100644
--- a/storage/innobase/include/row0merge.h
+++ b/storage/innobase/include/row0merge.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2005, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2021, MariaDB Corporation.
+Copyright (c) 2015, 2022, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -216,6 +216,11 @@ row_merge_is_index_usable(
 	const dict_index_t*	index)	/*!< in: index to check */
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
 
+/** Map from column numbers to column definitions that include
+changes to the collation, when the encoding is compatible with
+the original column and no table rebuild is needed */
+typedef std::map<unsigned, dict_col_t*> col_collations;
+
 /** Build indexes on a table by reading a clustered index, creating a temporary
 file containing index entries, merge sorting these index entries and inserting
 sorted index entries to indexes.
@@ -244,6 +249,7 @@ this function and it will be passed to other functions for further accounting.
 @param[in]	eval_table	mysql table used to evaluate virtual column
 				value, see innobase_get_computed_value().
 @param[in]	allow_non_null	allow the conversion from null to not-null
+@param[in]	col_collate	columns whose collations changed, or nullptr
 @return DB_SUCCESS or error code */
 dberr_t
 row_merge_build_indexes(
@@ -263,7 +269,8 @@ row_merge_build_indexes(
 	ut_stage_alter_t*	stage,
 	const dict_add_v_col_t*	add_v,
 	struct TABLE*		eval_table,
-	bool			allow_non_null)
+	bool			allow_non_null,
+	const col_collations*	col_collate)
 	MY_ATTRIBUTE((warn_unused_result));
 
 /********************************************************************//**
diff --git a/storage/innobase/row/row0log.cc b/storage/innobase/row/row0log.cc
index 28f0eb42825..eeac4b1712e 100644
--- a/storage/innobase/row/row0log.cc
+++ b/storage/innobase/row/row0log.cc
@@ -3877,6 +3877,23 @@ static void row_log_mark_other_online_index_abort(dict_table_t *table)
   table->drop_aborted= TRUE;
 }
 
+void dtype_t::assign(const dict_col_t &col)
+{
+  prtype= col.prtype;
+  mtype= col.mtype;
+  len= col.len;
+  mbminlen= col.mbminlen;
+  mbmaxlen= col.mbmaxlen;
+}
+
+inline void dtuple_t::copy_field_types(const dict_index_t &index)
+{
+  ut_ad(index.n_fields == n_fields);
+  if (UNIV_LIKELY_NULL(index.change_col_info))
+    for (ulint i= 0; i < n_fields; i++)
+      fields[i].type.assign(*index.fields[i].col);
+}
+
 void UndorecApplier::log_insert(const dtuple_t &tuple,
                                 dict_index_t *clust_index)
 {
@@ -3943,7 +3960,8 @@ void UndorecApplier::log_insert(const dtuple_t &tuple,
       {
         dtuple_t *entry= row_build_index_entry_low(row, ext, index,
                                                    heap, ROW_BUILD_NORMAL);
-        success= row_log_online_op(index, entry, trx_id);
+        entry->copy_field_types(*index);
+	success= row_log_online_op(index, entry, trx_id);
       }
 
       index->lock.s_unlock();
@@ -4069,11 +4087,15 @@ void UndorecApplier::log_update(const dtuple_t &tuple,
         dtuple_t *old_entry= row_build_index_entry_low(
           old_row, old_ext, index, heap, ROW_BUILD_NORMAL);
 
-        success= row_log_online_op(index, old_entry, 0);
+        old_entry->copy_field_types(*index);
+
+	success= row_log_online_op(index, old_entry, 0);
 
 	dtuple_t *new_entry= row_build_index_entry_low(
           row, new_ext, index, heap, ROW_BUILD_NORMAL);
 
+        new_entry->copy_field_types(*index);
+
 	if (success)
 	  success= row_log_online_op(index, new_entry, trx_id);
       }
@@ -4082,6 +4104,8 @@ void UndorecApplier::log_update(const dtuple_t &tuple,
         dtuple_t *old_entry= row_build_index_entry_low(
           row, new_ext, index, heap, ROW_BUILD_NORMAL);
 
+        old_entry->copy_field_types(*index);
+
         success= row_log_online_op(index, old_entry, 0);
       }
     }
diff --git a/storage/innobase/row/row0merge.cc b/storage/innobase/row/row0merge.cc
index c0870698c5b..60e9c1915e9 100644
--- a/storage/innobase/row/row0merge.cc
+++ b/storage/innobase/row/row0merge.cc
@@ -490,6 +490,7 @@ row_merge_buf_redundant_convert(
 @param[in,out]	v_heap		heap memory to process data for virtual column
 @param[in,out]	my_table	mysql table object
 @param[in]	trx		transaction object
+@param[in]	col_collate	columns whose collations changed, or nullptr
 @return number of rows added, 0 if out of space */
 static
 ulint
@@ -506,7 +507,8 @@ row_merge_buf_add(
 	dberr_t*		err,
 	mem_heap_t**		v_heap,
 	TABLE*			my_table,
-	trx_t*			trx)
+	trx_t*			trx,
+	const col_collations*	col_collate)
 {
 	ulint			i;
 	const dict_index_t*	index;
@@ -520,6 +522,7 @@ row_merge_buf_add(
 	doc_id_t		write_doc_id;
 	ulint			n_row_added = 0;
 	VCOL_STORAGE		vcol_storage;
+
 	DBUG_ENTER("row_merge_buf_add");
 
 	if (buf->n_tuples >= buf->max_tuples) {
@@ -611,8 +614,17 @@ error:
 				row_field = dtuple_get_nth_field(row,
 								 col->ind);
 				dfield_copy(field, row_field);
-			}
 
+				/* Copy the column collation to the
+				tuple field */
+				if (col_collate) {
+					auto it = col_collate->find(col->ind);
+					if (it != col_collate->end()) {
+						field->type
+							.assign(*it->second);
+					}
+				}
+			}
 
 			/* Tokenize and process data for FTS */
 			if (index->type & DICT_FTS) {
@@ -1657,6 +1669,7 @@ stage->inc() will be called for each page read.
 @param[in]	eval_table	mysql table used to evaluate virtual column
 				value, see innobase_get_computed_value().
 @param[in]	allow_not_null	allow null to not-null conversion
+@param[in]	col_collate	columns whose collations changed, or nullptr
 @return DB_SUCCESS or error */
 static MY_ATTRIBUTE((warn_unused_result))
 dberr_t
@@ -1684,7 +1697,8 @@ row_merge_read_clustered_index(
 	double 			pct_cost,
 	row_merge_block_t*	crypt_block,
 	struct TABLE*		eval_table,
-	bool			allow_not_null)
+	bool			allow_not_null,
+	const col_collations*	col_collate)
 {
 	dict_index_t*		clust_index;	/* Clustered index */
 	mem_heap_t*		row_heap = NULL;/* Heap memory to create
@@ -2391,7 +2405,8 @@ write_buffers:
 					buf, fts_index, old_table, new_table,
 					psort_info, row, ext, &doc_id,
 					conv_heap, &err,
-					&v_heap, eval_table, trx)))) {
+					&v_heap, eval_table, trx,
+					col_collate)))) {
 
 				/* If we are creating FTS index,
 				a single row can generate more
@@ -2718,7 +2733,8 @@ write_buffers:
 						buf, fts_index, old_table,
 						new_table, psort_info, row, ext,
 						&doc_id, conv_heap,
-						&err, &v_heap, eval_table, trx)))) {
+						&err, &v_heap, eval_table,
+						trx, col_collate)))) {
                                         /* An empty buffer should have enough
                                         room for at least one record. */
 					ut_ad(err == DB_COMPUTE_VALUE_FAILED
@@ -4422,6 +4438,7 @@ this function and it will be passed to other functions for further accounting.
 @param[in]	eval_table	mysql table used to evaluate virtual column
 				value, see innobase_get_computed_value().
 @param[in]	allow_not_null	allow the conversion from null to not-null
+@param[in]	col_collate	columns whose collations changed, or nullptr
 @return DB_SUCCESS or error code */
 dberr_t
 row_merge_build_indexes(
@@ -4441,7 +4458,8 @@ row_merge_build_indexes(
 	ut_stage_alter_t*	stage,
 	const dict_add_v_col_t*	add_v,
 	struct TABLE*		eval_table,
-	bool			allow_not_null)
+	bool			allow_not_null,
+	const col_collations*	col_collate)
 {
 	merge_file_t*		merge_files;
 	row_merge_block_t*	block;
@@ -4591,7 +4609,8 @@ row_merge_build_indexes(
 		fts_sort_idx, psort_info, merge_files, key_numbers,
 		n_indexes, defaults, add_v, col_map, add_autoinc,
 		sequence, block, skip_pk_sort, &tmpfd, stage,
-		pct_cost, crypt_block, eval_table, allow_not_null);
+		pct_cost, crypt_block, eval_table, allow_not_null,
+		col_collate);
 
 	stage->end_phase_read_pk();
 
diff --git a/storage/innobase/row/row0mysql.cc b/storage/innobase/row/row0mysql.cc
index 84f2b54f517..0c9ad03cc93 100644
--- a/storage/innobase/row/row0mysql.cc
+++ b/storage/innobase/row/row0mysql.cc
@@ -823,6 +823,10 @@ row_create_prebuilt(
 		DBUG_EXECUTE_IF("innodb_srch_key_buffer_max_value",
 			ut_a(temp_index->n_user_defined_cols
 						== MAX_REF_PARTS););
+		if (temp_index->is_corrupted()) {
+			continue;
+		}
+
 		uint temp_len = 0;
 		for (uint i = 0; i < temp_index->n_uniq; i++) {
 			ulint type = temp_index->fields[i].col->mtype;