diff --git a/mysql-test/include/mix1.inc b/mysql-test/include/mix1.inc
index 5e6a535fce5..0e1bdd1e0b8 100644
--- a/mysql-test/include/mix1.inc
+++ b/mysql-test/include/mix1.inc
@@ -1096,4 +1096,38 @@ select @b:=f2 from t1;
 select if(@a=@b,"ok","wrong");
 drop table t1;
 
+#
+# Bug#30747 Create table with identical constraint names behaves incorrectly
+#
+
+if ($test_foreign_keys)
+{
+  CREATE TABLE t1 (a INT NOT NULL, b INT NOT NULL, PRIMARY KEY (a,b)) engine=innodb;
+  --error ER_WRONG_FK_DEF
+  CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+                  CONSTRAINT c2 FOREIGN KEY f2 (c) REFERENCES t1 (a,b) ON UPDATE NO ACTION) engine=innodb;
+  --error ER_WRONG_FK_DEF
+  CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+                  CONSTRAINT c2 FOREIGN KEY (c) REFERENCES t1 (a,b) ON UPDATE NO ACTION) engine=innodb;
+  CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+                  CONSTRAINT c1 FOREIGN KEY c2 (c) REFERENCES t1 (a) ON DELETE NO ACTION,
+                  CONSTRAINT c2 FOREIGN KEY (c) REFERENCES t1 (a) ON UPDATE NO ACTION) engine=innodb;
+  ALTER TABLE t2 DROP FOREIGN KEY c2;
+  DROP TABLE t2;
+  --error ER_WRONG_FK_DEF
+  CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+                  FOREIGN KEY (c) REFERENCES t1 (a,k) ON UPDATE NO ACTION) engine=innodb;
+  --error ER_WRONG_FK_DEF
+  CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+                  FOREIGN KEY f1 (c) REFERENCES t1 (a,k) ON UPDATE NO ACTION) engine=innodb;
+  CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+                  CONSTRAINT c1 FOREIGN KEY f1 (c) REFERENCES t1 (a) ON DELETE NO ACTION,
+                  CONSTRAINT c2 FOREIGN KEY (c) REFERENCES t1 (a) ON UPDATE NO ACTION,
+                  FOREIGN KEY f3 (c) REFERENCES t1 (a) ON UPDATE NO ACTION,
+                  FOREIGN KEY (c) REFERENCES t1 (a) ON UPDATE NO ACTION) engine=innodb;
+  SHOW CREATE TABLE t2;
+  DROP TABLE t2;
+  DROP TABLE t1;
+}
+
 --echo End of 5.1 tests
diff --git a/mysql-test/r/innodb_mysql.result b/mysql-test/r/innodb_mysql.result
index 32c692501ad..cc1a0cc61ab 100644
--- a/mysql-test/r/innodb_mysql.result
+++ b/mysql-test/r/innodb_mysql.result
@@ -1273,4 +1273,40 @@ select if(@a=@b,"ok","wrong");
 if(@a=@b,"ok","wrong")
 ok
 drop table t1;
+CREATE TABLE t1 (a INT NOT NULL, b INT NOT NULL, PRIMARY KEY (a,b)) engine=innodb;
+CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+CONSTRAINT c2 FOREIGN KEY f2 (c) REFERENCES t1 (a,b) ON UPDATE NO ACTION) engine=innodb;
+ERROR 42000: Incorrect foreign key definition for 'f2': Key reference and table reference don't match
+CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+CONSTRAINT c2 FOREIGN KEY (c) REFERENCES t1 (a,b) ON UPDATE NO ACTION) engine=innodb;
+ERROR 42000: Incorrect foreign key definition for 'c2': Key reference and table reference don't match
+CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+CONSTRAINT c1 FOREIGN KEY c2 (c) REFERENCES t1 (a) ON DELETE NO ACTION,
+CONSTRAINT c2 FOREIGN KEY (c) REFERENCES t1 (a) ON UPDATE NO ACTION) engine=innodb;
+ALTER TABLE t2 DROP FOREIGN KEY c2;
+DROP TABLE t2;
+CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+FOREIGN KEY (c) REFERENCES t1 (a,k) ON UPDATE NO ACTION) engine=innodb;
+ERROR 42000: Incorrect foreign key definition for 'foreign key without name': Key reference and table reference don't match
+CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+FOREIGN KEY f1 (c) REFERENCES t1 (a,k) ON UPDATE NO ACTION) engine=innodb;
+ERROR 42000: Incorrect foreign key definition for 'f1': Key reference and table reference don't match
+CREATE TABLE t2 (c INT NOT NULL, d INT NOT NULL, PRIMARY KEY (c,d),
+CONSTRAINT c1 FOREIGN KEY f1 (c) REFERENCES t1 (a) ON DELETE NO ACTION,
+CONSTRAINT c2 FOREIGN KEY (c) REFERENCES t1 (a) ON UPDATE NO ACTION,
+FOREIGN KEY f3 (c) REFERENCES t1 (a) ON UPDATE NO ACTION,
+FOREIGN KEY (c) REFERENCES t1 (a) ON UPDATE NO ACTION) engine=innodb;
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `c` int(11) NOT NULL,
+  `d` int(11) NOT NULL,
+  PRIMARY KEY (`c`,`d`),
+  CONSTRAINT `c1` FOREIGN KEY (`c`) REFERENCES `t1` (`a`) ON DELETE NO ACTION,
+  CONSTRAINT `c2` FOREIGN KEY (`c`) REFERENCES `t1` (`a`) ON UPDATE NO ACTION,
+  CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`c`) REFERENCES `t1` (`a`) ON UPDATE NO ACTION,
+  CONSTRAINT `t2_ibfk_2` FOREIGN KEY (`c`) REFERENCES `t1` (`a`) ON UPDATE NO ACTION
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+DROP TABLE t2;
+DROP TABLE t1;
 End of 5.1 tests
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index b5b451cfe3e..1f6ea170a10 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -4656,8 +4656,9 @@ key_def:
         | opt_constraint FOREIGN KEY_SYM opt_ident '(' key_list ')' references
           {
             LEX *lex=Lex;
-            const char *key_name= $4 ? $4 : $1;
-            Key *key= new Foreign_key(key_name, lex->col_list,
+            const char *key_name= $1 ? $1 : $4;
+            const char *fkey_name = $4 ? $4 : key_name;
+            Key *key= new Foreign_key(fkey_name, lex->col_list,
                                       $8,
                                       lex->ref_list,
                                       lex->fk_delete_opt,