MDEV-28933 CREATE OR REPLACE fails to recreate same constraint name

Use temporary constraint names for temporary tables. The constraints
are not added to cache (skipped in dict_table_rename_in_cache()).

The scheme for temporary constraint names is as follows:

    for old table: db_name/\xFFconstraint_name
    for new table: db_name/\xFF\xFFconstraint_name

normalize_table_name_c_low(): wrong comparison "less than FN_REFLEN -
1". Somewhere array of FN_REFLEN includes the trailing 0, somewhere
array of FN_REFLEN + 1 includes trailing 0, but nowhere array of
FN_REFLEN - 1 must include trailing 0.

Change from original MDEV-28933 fix:

As temporary FK is now required for any ALTER operation (especially
partitioning operations) row_rename_table_for_mysql() does FK rename
on both RENAME_FK and RENAME_ALTER_COPY (see do_rename_fk).

mysql-test/suite/binlog/r/start_alter_mysqlbinlog_replay.result

@@ -11,7 +11,7 @@ set binlog_alter_two_phase = ON;
 create table t1 (f1 int primary key) engine=InnoDB;
 create table t2 (f1 int primary key, constraint c1 foreign key (f1) references t1(f1)) engine=innodb;
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
-ERROR HY000: Can't create table `test`.`t2` (errno: 121 "Duplicate key on write or update")
+ERROR HY000: Duplicate ALTER TABLE constraint name '???'
 drop table t2, t1;
 select @@gtid_binlog_state;
 @@gtid_binlog_state

mysql-test/suite/binlog/t/start_alter_mysqlbinlog_replay.test

@@ -21,7 +21,7 @@ set binlog_alter_two_phase = ON;
 create table t1 (f1 int primary key) engine=InnoDB;
 create table t2 (f1 int primary key, constraint c1 foreign key (f1) references t1(f1)) engine=innodb;
 
---error ER_CANT_CREATE_TABLE
+--error ER_DUP_CONSTRAINT_NAME
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
 
 drop table t2, t1;

mysql-test/suite/innodb/r/add_constraint.result

@@ -6,7 +6,7 @@ create table t2(a int, b int, key(a),key(b))engine=innodb;
 alter table t2 add constraint b foreign key (b) references t1(a);
 alter table t1 add constraint b1 foreign key (b) references t2(a);
 alter table t2 add constraint b1 foreign key (b) references t1(a);
-ERROR HY000: Can't create table `test`.`t2` (errno: 121 "Duplicate key on write or update")
+ERROR HY000: Duplicate ALTER TABLE constraint name '???'
 alter table t2 drop foreign key b;
 alter table t1 drop foreign key b1;
 drop table t2;

mysql-test/suite/innodb/r/foreign_key.result

@@ -11,7 +11,7 @@ ERROR HY000: Can't create table `test`.`t2` (errno: 150 "Foreign key constraint
 create table t2 (f1 int primary key,
 constraint c1 foreign key (f1) references t1(f1)) engine=innodb;
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
-ERROR HY000: Can't create table `test`.`t2` (errno: 121 "Duplicate key on write or update")
+ERROR HY000: Duplicate ALTER TABLE constraint name '???'
 set foreign_key_checks = 0;
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
 ERROR HY000: Duplicate FOREIGN KEY constraint name 'test/c1'
@@ -210,7 +210,7 @@ CONSTRAINT t2_ibfk_1 FOREIGN KEY (a) REFERENCES t1(a)) ENGINE=InnoDB;
 CREATE TABLE best.t2 (a INT PRIMARY KEY, b TEXT, FULLTEXT INDEX(b),
 FOREIGN KEY (a) REFERENCES test.t1(a)) ENGINE=InnoDB;
 RENAME TABLE best.t2 TO test.t2;
-ERROR 42S01: Table 't2' already exists
+ERROR HY000: Duplicate ALTER TABLE constraint name '???'
 SHOW CREATE TABLE best.t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (

mysql-test/suite/innodb/r/foreign_key_not_windows.result

@@ -6,11 +6,20 @@ CREATE DATABASE `d255`;
 CREATE TABLE `d255`.`d255`
 (a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
 ERROR HY000: Long database name and identifier for object resulted in path length exceeding 512 characters. Path: './@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023/@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@
+CREATE OR REPLACE TABLE `d255`.`d255`
+(a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+ERROR HY000: Long database name and identifier for object resulted in path length exceeding 512 characters. Path: './@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023/@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@
 CREATE TABLE `d255`.`_##################################################`
 (a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
 ERROR HY000: Long database name and identifier for object resulted in path length exceeding 512 characters. Path: './@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023/_@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023
+CREATE OR REPLACE TABLE `d255`.`_##################################################`
+(a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+ERROR HY000: Long database name and identifier for object resulted in path length exceeding 512 characters. Path: './@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023/_@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023@0023
 CREATE TABLE `d255`.`##################################################`
 (a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+CREATE OR REPLACE TABLE `d255`.`d245`
+(a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+DROP TABLE `d255`.`d245`;
 #
 # MDEV-29258 Failing assertion for name length on RENAME TABLE
 #
@@ -29,3 +38,37 @@ RENAME TABLE `d255`.u TO u;
 DROP TABLE u;
 DROP DATABASE `d255`;
 # End of 10.3 tests
+#
+# MDEV-28933 CREATE OR REPLACE fails to recreate same constraint name
+#
+set names utf8;
+create database `❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎`;
+use `❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎`;
+create table t (a int primary key) engine=innodb;
+create table u (
+a int primary key,
+constraint `❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎` foreign key d (a) references t (a)) engine=innodb;
+select * from information_schema.innodb_sys_foreign;
+ID	FOR_NAME	REF_NAME	N_COLS	TYPE
+@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	1	0
+select * from information_schema.innodb_sys_foreign_cols;
+ID	FOR_COL_NAME	REF_COL_NAME	POS
+@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	a	a	0
+create or replace table u (
+a int primary key,
+constraint `❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎` foreign key d (a) references t (a)) engine=innodb;
+select * from information_schema.innodb_sys_foreign;
+ID	FOR_NAME	REF_NAME	N_COLS	TYPE
+@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	1	0
+select * from information_schema.innodb_sys_foreign_cols;
+ID	FOR_COL_NAME	REF_COL_NAME	POS
+@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@274e@27	a	a	0
+show create table u;
+Table	Create Table
+u	CREATE TABLE `u` (
+  `a` int(11) NOT NULL,
+  PRIMARY KEY (`a`),
+  CONSTRAINT `❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎` FOREIGN KEY (`a`) REFERENCES `t` (`a`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
+use test;
+drop database `❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎❎`;

mysql-test/suite/innodb/r/innodb-index.result

@@ -509,7 +509,7 @@ t4	CREATE TABLE `t4` (
   CONSTRAINT `dc` FOREIGN KEY (`a`) REFERENCES `t1` (`a`)
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
 alter table t3 add constraint dc foreign key (a) references t1(a);
-ERROR HY000: Can't create table `test`.`t3` (errno: 121 "Duplicate key on write or update")
+ERROR HY000: Duplicate ALTER TABLE constraint name '???'
 SET FOREIGN_KEY_CHECKS=0;
 alter table t3 add constraint dc foreign key (a) references t1(a);
 ERROR HY000: Failed to add the foreign key constraint 'test/dc' to system tables

mysql-test/suite/innodb/t/add_constraint.test

@@ -10,7 +10,7 @@ create table t2(a int, b int, key(a),key(b))engine=innodb;
 alter table t2 add constraint b foreign key (b) references t1(a);
 alter table t1 add constraint b1 foreign key (b) references t2(a);
 
---error ER_CANT_CREATE_TABLE
+--error ER_DUP_CONSTRAINT_NAME
 alter table t2 add constraint b1 foreign key (b) references t1(a);
 
 alter table t2 drop foreign key b;

mysql-test/suite/innodb/t/foreign_key.test

@@ -17,7 +17,7 @@ constraint c1 foreign key (f1) references t1(f1)) engine=InnoDB;
 create table t2 (f1 int primary key,
    constraint c1 foreign key (f1) references t1(f1)) engine=innodb;
 
---error ER_CANT_CREATE_TABLE
+--error ER_DUP_CONSTRAINT_NAME
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
 
 set foreign_key_checks = 0;
@@ -195,7 +195,7 @@ CONSTRAINT t2_ibfk_1 FOREIGN KEY (a) REFERENCES t1(a)) ENGINE=InnoDB;
 CREATE TABLE best.t2 (a INT PRIMARY KEY, b TEXT, FULLTEXT INDEX(b),
 FOREIGN KEY (a) REFERENCES test.t1(a)) ENGINE=InnoDB;
 --replace_regex /Table '.*t2'/Table 't2'/
---error ER_TABLE_EXISTS_ERROR
+--error ER_DUP_CONSTRAINT_NAME
 RENAME TABLE best.t2 TO test.t2;
 SHOW CREATE TABLE best.t2;
 DROP DATABASE best;

mysql-test/suite/innodb/t/foreign_key_not_windows.test

@@ -25,20 +25,43 @@ CREATE TABLE t (a INT PRIMARY KEY) ENGINE=InnoDB;
 # corresponding to the 51 characters below: 5*51=255.
 let $d255=###################################################;
 let $d250=##################################################;
+let $d245=#####################;
+# FIXME: MDEV-29258
+# let $d245=#################################################;
 --replace_result $d255 d255
 eval CREATE DATABASE `$d255`;
+
 --replace_result $d255 d255
 --error ER_IDENT_CAUSES_TOO_LONG_PATH
 eval CREATE TABLE `$d255`.`$d255`
 (a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+
+--replace_result $d255 d255
+--error ER_IDENT_CAUSES_TOO_LONG_PATH
+eval CREATE OR REPLACE TABLE `$d255`.`$d255`
+(a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+
 --replace_result $d255 d255
 --error ER_IDENT_CAUSES_TOO_LONG_PATH
 eval CREATE TABLE `$d255`.`_$d250`
 (a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+
+--replace_result $d255 d255
+--error ER_IDENT_CAUSES_TOO_LONG_PATH
+eval CREATE OR REPLACE TABLE `$d255`.`_$d250`
+(a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+
 --replace_result $d255 d255
 eval CREATE TABLE `$d255`.`$d250`
 (a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
 
+--replace_result $d255 d255 $d245 d245
+eval CREATE OR REPLACE TABLE `$d255`.`$d245`
+(a INT PRIMARY KEY, FOREIGN KEY(a) REFERENCES test.t(a)) ENGINE=InnoDB;
+
+--replace_result $d255 d255 $d245 d245
+eval DROP TABLE `$d255`.`$d245`;
+
 --echo #
 --echo # MDEV-29258 Failing assertion for name length on RENAME TABLE
 --echo #
@@ -53,7 +76,6 @@ eval DROP TABLE `$d255`.`$d250`;
 eval RENAME TABLE `$d255`.`$d245` TO `$d255`.`$d250`;
 --replace_result $d250 d250 $d255 d255
 eval RENAME TABLE `$d255`.`$d250` TO a;
---replace_result $d255 d255
 DROP TABLE a,t;
 
 --echo #
@@ -75,3 +97,26 @@ DROP TABLE u;
 eval DROP DATABASE `$d255`;
 
 --echo # End of 10.3 tests
+
+--echo #
+--echo # MDEV-28933 CREATE OR REPLACE fails to recreate same constraint name
+--echo #
+set names utf8;
+let $d= `select repeat('❎', 45)`;
+let $t= `select repeat('❎', 64)`;
+eval create database `$d`;
+eval use `$d`;
+create table t (a int primary key) engine=innodb;
+eval create table u (
+  a int primary key,
+  constraint `$t` foreign key d (a) references t (a)) engine=innodb;
+select * from information_schema.innodb_sys_foreign;
+select * from information_schema.innodb_sys_foreign_cols;
+eval create or replace table u (
+  a int primary key,
+  constraint `$t` foreign key d (a) references t (a)) engine=innodb;
+select * from information_schema.innodb_sys_foreign;
+select * from information_schema.innodb_sys_foreign_cols;
+show create table u;
+use test;
+eval drop database `$d`;

mysql-test/suite/innodb/t/innodb-index.test

@@ -221,7 +221,7 @@ show create table t4;
 # Embedded server doesn't chdir to data directory
 --replace_result $MYSQLD_DATADIR ./ master-data/ ''
 # a foreign key 'test/dc' already exists
---error ER_CANT_CREATE_TABLE
+--error ER_DUP_CONSTRAINT_NAME
 alter table t3 add constraint dc foreign key (a) references t1(a);
 SET FOREIGN_KEY_CHECKS=0;
 --error ER_FK_FAIL_ADD_SYSTEM

mysql-test/suite/rpl/r/rpl_alter_rollback.result

@@ -15,7 +15,7 @@ ERROR HY000: Can't create table `test`.`t2` (errno: 150 "Foreign key constraint
 create table t2 (f1 int primary key,
 constraint c1 foreign key (f1) references t1(f1)) engine=innodb;
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
-ERROR HY000: Can't create table `test`.`t2` (errno: 121 "Duplicate key on write or update")
+ERROR HY000: Duplicate ALTER TABLE constraint name '???'
 include/show_binlog_events.inc
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 master-bin.000001	#	Gtid	#	#	GTID #-#-#

mysql-test/suite/rpl/t/rpl_alter_rollback.test

@@ -22,7 +22,7 @@ constraint c1 foreign key (f1) references t1(f1)) engine=InnoDB;
 create table t2 (f1 int primary key,
    constraint c1 foreign key (f1) references t1(f1)) engine=innodb;
 
---error ER_CANT_CREATE_TABLE
+--error ER_DUP_CONSTRAINT_NAME
 alter table t2 add constraint c1 foreign key (f1) references t1(f1);
 --source include/show_binlog_events.inc
 

mysql-test/suite/versioning/r/foreign.result

@@ -263,6 +263,13 @@ constraint `fk_child_parent`
 on delete cascade
 on update cascade
 ) engine = innodb with system versioning;
+select * from information_schema.innodb_sys_foreign;
+ID	FOR_NAME	REF_NAME	N_COLS	TYPE
+test/fk_child_parent	test/child	test/parent	2	5
+select * from information_schema.innodb_sys_foreign_cols;
+ID	FOR_COL_NAME	REF_COL_NAME	POS
+test/fk_child_parent	parent_id	id	0
+test/fk_child_parent	parent_value	value	1
 create or replace table subchild (
 id int not null auto_increment primary key,
 parent_id smallint unsigned not null,
@@ -272,6 +279,16 @@ constraint `fk_subchild_child_parent`
 on delete cascade
 on update cascade
 ) engine=innodb;
+select * from information_schema.innodb_sys_foreign;
+ID	FOR_NAME	REF_NAME	N_COLS	TYPE
+test/fk_child_parent	test/child	test/parent	2	5
+test/fk_subchild_child_parent	test/subchild	test/child	2	5
+select * from information_schema.innodb_sys_foreign_cols;
+ID	FOR_COL_NAME	REF_COL_NAME	POS
+test/fk_child_parent	parent_id	id	0
+test/fk_child_parent	parent_value	value	1
+test/fk_subchild_child_parent	parent_id	parent_id	0
+test/fk_subchild_child_parent	parent_value	parent_value	1
 insert into parent (value) values (23);
 select id, value from parent into @id, @value;
 insert into child values (default, @id, @value);

mysql-test/suite/versioning/t/foreign.test

@@ -304,6 +304,9 @@ eval create or replace table child (
     on update cascade
 ) engine = innodb with system versioning;
 
+select * from information_schema.innodb_sys_foreign;
+select * from information_schema.innodb_sys_foreign_cols;
+
 create or replace table subchild (
   id int not null auto_increment primary key,
   parent_id smallint unsigned not null,
@@ -314,6 +317,9 @@ create or replace table subchild (
     on update cascade
 ) engine=innodb;
 
+select * from information_schema.innodb_sys_foreign;
+select * from information_schema.innodb_sys_foreign_cols;
+
 insert into parent (value) values (23);
 --enable_prepare_warnings
 select id, value from parent into @id, @value;

sql/lex_ident.h

@@ -586,7 +586,7 @@ class Identifier_chain2
   size_t make_sep_name_opt_casedn(char *dst, size_t dst_size,
                                   int sep, bool casedn) const
   {
-    DBUG_ASSERT(m_name[0].length + m_name[1].length + 2 < FN_REFLEN - 1);
+    DBUG_ASSERT(m_name[0].length + m_name[1].length + 2 < FN_REFLEN);
     return casedn ? make_sep_name_casedn(dst, dst_size, sep) :
                     make_sep_name(dst, dst_size, sep);
   }

sql/sql_table.cc

@@ -5336,6 +5336,12 @@ mysql_rename_table(handlerton *base, const LEX_CSTRING *old_db,
 
   if (error == HA_ERR_WRONG_COMMAND)
     my_error(ER_NOT_SUPPORTED_YET, MYF(0), "ALTER TABLE");
+  if (error == HA_ERR_FOREIGN_DUPLICATE_KEY)
+    /*
+       TODO: constraint name is not known because rename_constraint_ids
+       does not supply it in row_rename_table_for_mysql()
+    */
+    my_error(ER_DUP_CONSTRAINT_NAME, MYF(0), "ALTER TABLE", "???");
   else if (error ==  ENOTDIR)
     my_error(ER_BAD_DB_ERROR, MYF(0), new_db->str);
   else if (error)

storage/innobase/dict/dict0dict.cc

@@ -1617,7 +1617,8 @@ dict_table_rename_in_cache(
 			foreign->heap, table->name.m_name);
 		foreign->foreign_table_name_lookup_set();
 
-		if (strchr(foreign->id, '/')) {
+		const bool tmp_id = (strchr(foreign->id, '\xFF') != NULL);
+		if (!tmp_id && strchr(foreign->id, '/')) {
 			/* This is a >= 4.0.18 format id */
 
 			ulint	db_len;
@@ -1761,10 +1762,17 @@ dict_table_rename_in_cache(
 		}
 
 		table->foreign_set.erase(it);
-		fk_set.insert(foreign);
 
-		if (foreign->referenced_table) {
-			foreign->referenced_table->referenced_set.insert(foreign);
+		if (!tmp_id) {
+			fk_set.insert(foreign);
+
+			if (foreign->referenced_table) {
+				foreign->referenced_table
+					->referenced_set.insert(foreign);
+			}
+		} else {
+			/* foreign was not added to cache, free it */
+			dict_foreign_free(foreign);
 		}
 	}
 

storage/innobase/dict/dict0load.cc

@@ -3163,8 +3163,8 @@ dict_load_foreigns(
 		rec, DICT_FLD__SYS_FOREIGN_FOR_NAME__ID, &len);
 
 	/* Copy the string because the page may be modified or evicted
-	after mtr.commit() below. */
-	char	fk_id[MAX_TABLE_NAME_LEN + NAME_LEN];
+	after mtr.commit() below (-2 is for \xFF\xFF in tmp constraints). */
+	char	fk_id[MAX_TABLE_NAME_LEN + NAME_LEN - 2];
 	err = DB_SUCCESS;
 	if (UNIV_LIKELY(len < sizeof fk_id)) {
 		memcpy(fk_id, field, len);

storage/innobase/handler/ha_innodb.cc

@@ -5297,7 +5297,8 @@ create_table_info_t::create_table_info_t(
 	  m_create_info(create_info),
 	  m_table(NULL),
 	  m_innodb_file_per_table(file_per_table),
-	  m_creating_stub(thd_ddl_options(thd)->import_tablespace())
+	  m_creating_stub(thd_ddl_options(thd)->import_tablespace()),
+	  alter_table(NULL)
 {
   m_table_name[0]= '\0';
   m_remote_path[0]= '\0';
@@ -12258,7 +12259,6 @@ create_table_info_t::create_foreign_keys()
 	LEX_CSTRING name= {m_table_name, strlen(m_table_name)};
 
 	if (sqlcom == SQLCOM_ALTER_TABLE) {
-		dict_table_t* alter_table;
 		mem_heap_t* heap = mem_heap_create(10000);
 		LEX_CSTRING table_name = m_form->s->table_name;
 		CHARSET_INFO* to_cs = &my_charset_filename;
@@ -12313,6 +12313,15 @@ create_table_info_t::create_foreign_keys()
 				alter_table);
 		}
 
+		/*
+			alter_table == NULL might be by the following reasons:
+
+			1. tmp_table;
+			2. is_partition(m_table_name);
+			3. Engine changed from non-InnoDB, so no original table in InnoDB;
+			4. Anything else?
+		*/
+
 		*innobase_convert_name(create_name, sizeof create_name,
 				       n, strlen(n), m_thd) = '\0';
 		mem_heap_free(heap);
@@ -12474,6 +12483,7 @@ create_table_info_t::create_foreign_key(
 
 		if (fk->constraint_name.str) {
 			ulint db_len;
+			const bool tmp= alter_table;
 
 			/* Catenate 'databasename/' to the constraint name
 			specified by the user: we conceive the constraint as
@@ -12483,13 +12493,17 @@ create_table_info_t::create_foreign_key(
 			db_len = dict_get_db_name_len(table->name.m_name);
 
 			foreign->id = static_cast<char*>(mem_heap_alloc(
-				foreign->heap,
-				db_len + fk->constraint_name.length + 2));
-
-			memcpy(foreign->id, table->name.m_name, db_len);
-			foreign->id[db_len] = '/';
-			strcpy(foreign->id + db_len + 1,
-			       fk->constraint_name.str);
+				foreign->heap, (tmp ? 3 : 2)
+				+ db_len + fk->constraint_name.length));
+
+			char *pos = foreign->id;
+			memcpy(pos, table->name.m_name, db_len);
+			pos += db_len;
+			*(pos++) = '/';
+			if (tmp) {
+				*(pos++) = '\xFF';
+			}
+			strcpy(pos, fk->constraint_name.str);
 		}
 
 		if (foreign->id == NULL) {

storage/innobase/handler/ha_innodb.h

@@ -780,6 +780,7 @@ class create_table_info_t
 
 	/** Whether we are creating a stub table for importing. */
 	const bool	m_creating_stub;
+	dict_table_t* alter_table;
 };
 
 /**

storage/innobase/include/sql_funcs.h

@@ -32,12 +32,15 @@ R"===(PROCEDURE RENAME_CONSTRAINT_IDS () IS
   gen_constr_prefix CHAR;
   new_db_name CHAR;
   foreign_id CHAR;
+  foreign_id2 CHAR;
+  constr_name CHAR;
   new_foreign_id CHAR;
   old_db_name_len INT;
-  old_t_name_len INT;
   new_db_name_len INT;
   id_len INT;
   offset INT;
+  offset2 INT;
+  constr_name_len INT;
   found INT;
   BEGIN
   found := 1;
@@ -45,7 +48,6 @@ R"===(PROCEDURE RENAME_CONSTRAINT_IDS () IS
   new_db_name_len := INSTR(:new_table_name, '/') - 1;
   new_db_name := SUBSTR(:new_table_name, 0,
                         new_db_name_len);
-  old_t_name_len := LENGTH(:old_table_name);
   gen_constr_prefix := CONCAT(:old_table_name_utf8,
                               '_ibfk_');
   WHILE found = 1 LOOP
@@ -62,6 +64,18 @@ R"===(PROCEDURE RENAME_CONSTRAINT_IDS () IS
       SET FOR_NAME = :new_table_name
       WHERE ID = foreign_id;
       id_len := LENGTH(foreign_id);
+      foreign_id2 := foreign_id;
+      offset := INSTR(foreign_id, ')===" "\xFF" R"===(');
+      IF (SUBSTR(foreign_id, offset, 1) = ')===" "\xFF" R"===(') THEN
+        offset2 := offset + 1;
+      ELSE
+        offset2 := offset;
+      END IF;
+      IF (:old_is_tmp > 0 AND offset > 0) THEN
+        foreign_id := CONCAT(SUBSTR(foreign_id2, 0, offset - 1),
+                             SUBSTR(foreign_id2, offset2, id_len - offset2));
+        id_len := LENGTH(foreign_id);
+      END IF;
       IF (INSTR(foreign_id, '/') > 0) THEN
         IF (INSTR(foreign_id,
                   gen_constr_prefix) > 0)
@@ -71,17 +85,22 @@ R"===(PROCEDURE RENAME_CONSTRAINT_IDS () IS
           CONCAT(:new_table_utf8,
                  SUBSTR(foreign_id, offset, id_len - offset));
         ELSE
-          new_foreign_id :=
-          CONCAT(new_db_name,
-                  SUBSTR(foreign_id, old_db_name_len,
-                         id_len - old_db_name_len));
+          constr_name_len := id_len - old_db_name_len;
+          constr_name := SUBSTR(foreign_id, old_db_name_len,
+                                constr_name_len);
+          IF (:new_is_tmp > 0) THEN
+            new_foreign_id := CONCAT(new_db_name, ')===" "/\xFF\xFF" R"===(',
+                                     SUBSTR(constr_name, 1, constr_name_len - 1));
+          ELSE
+            new_foreign_id := CONCAT(new_db_name, constr_name);
+          END IF;
         END IF;
         UPDATE SYS_FOREIGN
           SET ID = new_foreign_id
-          WHERE ID = foreign_id;
+          WHERE ID = foreign_id2;
         UPDATE SYS_FOREIGN_COLS
           SET ID = new_foreign_id
-          WHERE ID = foreign_id;
+          WHERE ID = foreign_id2;
       END IF;
     END IF;
   END LOOP;

storage/innobase/row/row0mysql.cc

@@ -2681,6 +2681,7 @@ row_rename_table_for_mysql(
 		char	new_table_name[MAX_TABLE_NAME_LEN + 1];
 		char	old_table_utf8[MAX_TABLE_NAME_LEN + 1];
 		uint	errors = 0;
+		const bool do_rename_fk = (fk == RENAME_FK || fk == RENAME_ALTER_COPY);
 
 		strncpy(old_table_utf8, old_name, MAX_TABLE_NAME_LEN);
 		old_table_utf8[MAX_TABLE_NAME_LEN] = '\0';
@@ -2720,8 +2721,22 @@ row_rename_table_for_mysql(
 		}
 
 		pars_info_add_str_literal(info, "new_table_utf8", new_table_name);
+		/* Old foreign ID for temporary constraint was written like this:
+			db_name/\xFFconstraint_name */
+		pars_info_add_int4_literal(info, "old_is_tmp",
+					   do_rename_fk && old_is_tmp);
+		/* New foreign ID for temporary constraint is written like this:
+			db_name/\xFF\xFFconstraint_name */
+		pars_info_add_int4_literal(info, "new_is_tmp",
+					   do_rename_fk && new_is_tmp);
 
 		err = que_eval_sql(info, rename_constraint_ids, trx);
+		/*
+		 Higher layer should throw not ER_TABLE_EXISTS_ERROR but
+		 ER_ERROR_ON_RENAME with explanation about foreign keys.
+		*/
+		if (err == DB_DUPLICATE_KEY)
+			err = DB_FOREIGN_DUPLICATE_KEY;
 
 	} else if (n_constraints_to_drop > 0) {
 		/* Drop some constraints of tmp tables. */