More tests for SEQUENCE's

- Test with LOCK TABLES
- Test mysqldump
- Don't update rows for sequence tables if values doesn't change. This is
  needed as InnoDB gives an error for updates where values doesn't change.

mysql-test/suite/sql_sequence/mysqldump.result

+CREATE SEQUENCE a1 engine=aria;
+CREATE TABLE t1(a INT, KEY (a)) KEY_BLOCK_SIZE=1024;
+insert into t1 values (1),(2);
+CREATE SEQUENCE x1 engine=innodb;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `a1` (
+  `next_value` bigint(21) NOT NULL COMMENT 'next not cached value',
+  `min_value` bigint(21) NOT NULL COMMENT 'min value',
+  `max_value` bigint(21) NOT NULL COMMENT 'max value',
+  `start` bigint(21) NOT NULL COMMENT 'start value',
+  `increment` bigint(21) NOT NULL COMMENT 'increment value',
+  `cache` bigint(21) NOT NULL COMMENT 'cache size',
+  `cycle` tinyint(1) unsigned NOT NULL COMMENT 'cycle state',
+  `round` bigint(21) NOT NULL COMMENT 'How many cycles has been done'
+) ENGINE=Aria SEQUENCE=1;
+/*!40101 SET character_set_client = @saved_cs_client */;
+INSERT INTO `a1` VALUES (1,1,9223372036854775806,1,1,1000,0,0);
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `t1` (
+  `a` int(11) DEFAULT NULL,
+  KEY `a` (`a`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 KEY_BLOCK_SIZE=1024;
+/*!40101 SET character_set_client = @saved_cs_client */;
+INSERT INTO `t1` VALUES (1),(2);
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `x1` (
+  `next_value` bigint(21) NOT NULL COMMENT 'next not cached value',
+  `min_value` bigint(21) NOT NULL COMMENT 'min value',
+  `max_value` bigint(21) NOT NULL COMMENT 'max value',
+  `start` bigint(21) NOT NULL COMMENT 'start value',
+  `increment` bigint(21) NOT NULL COMMENT 'increment value',
+  `cache` bigint(21) NOT NULL COMMENT 'cache size',
+  `cycle` tinyint(1) unsigned NOT NULL COMMENT 'cycle state',
+  `round` bigint(21) NOT NULL COMMENT 'How many cycles has been done'
+) ENGINE=InnoDB SEQUENCE=1;
+/*!40101 SET character_set_client = @saved_cs_client */;
+INSERT INTO `x1` VALUES (1,1,9223372036854775806,1,1,1000,0,0);
+DROP TABLE a1,t1,x1;

mysql-test/suite/sql_sequence/mysqldump.test

+#
+# Testing mysqldump of sequences
+#
+
+# Embedded server doesn't support external clients
+--source include/not_embedded.inc
+--source include/have_aria.inc
+--source include/have_innodb.inc
+
+CREATE SEQUENCE a1 engine=aria;
+CREATE TABLE t1(a INT, KEY (a)) KEY_BLOCK_SIZE=1024;
+insert into t1 values (1),(2);
+CREATE SEQUENCE x1 engine=innodb;
+--exec $MYSQL_DUMP --compact test
+DROP TABLE a1,t1,x1;

mysql-test/suite/sql_sequence/other.result

@@ -82,3 +82,34 @@ ERROR HY000: Storage engine SEQUENCE of the table `test`.`s1` doesn't have this
 delete from s1 where next_value > 0;
 ERROR HY000: Storage engine SEQUENCE of the table `test`.`s1` doesn't have this option
 drop sequence s1;
+#
+# SHOW TABLES
+#
+create sequence s1;
+create table t1 (a int);
+create view v1 as select * from s1;
+show full tables;
+Tables_in_test	Table_type
+s1	SEQUENCE
+t1	BASE TABLE
+v1	VIEW
+SELECT TABLE_TYPE,ENGINE FROM INFORMATION_SCHEMA.TABLES where table_schema="test";
+TABLE_TYPE	ENGINE
+SEQUENCE	MyISAM
+BASE TABLE	MyISAM
+VIEW	NULL
+drop table t1,s1;
+drop view v1;
+#
+# LOCK TABLES (as in mysqldump)
+#
+create sequence s1 engine=innodb;
+LOCK TABLES s1 READ;
+SELECT * from s1;
+next_value	min_value	max_value	start	increment	cache	cycle	round
+1	1	9223372036854775806	1	1	1000	0	0
+UNLOCK TABLES;
+LOCK TABLES s1 WRITE;
+insert into s1 values (1,1,9223372036854775806, 1, 1, 1000, 0, 0);
+UNLOCK TABLES;
+drop table s1;

mysql-test/suite/sql_sequence/other.test

@@ -65,3 +65,28 @@ update s1 set next_value=100;
 --error ER_ILLEGAL_HA
 delete from s1 where next_value > 0;
 drop sequence s1;
+
+--echo #
+--echo # SHOW TABLES
+--echo #
+
+create sequence s1;
+create table t1 (a int);
+create view v1 as select * from s1;
+show full tables;
+SELECT TABLE_TYPE,ENGINE FROM INFORMATION_SCHEMA.TABLES where table_schema="test";
+drop table t1,s1;
+drop view v1;
+
+--echo #
+--echo # LOCK TABLES (as in mysqldump)
+--echo #
+
+create sequence s1 engine=innodb;
+LOCK TABLES s1 READ;
+SELECT * from s1;
+UNLOCK TABLES;
+LOCK TABLES s1 WRITE;
+insert into s1 values (1,1,9223372036854775806, 1, 1, 1000, 0, 0);
+UNLOCK TABLES;
+drop table s1;

sql/handler.cc

@@ -6041,7 +6041,13 @@ int handler::update_first_row(uchar *new_data)
   {
     int end_error;
     if (!(error= ha_rnd_next(table->record[1])))
-      error= update_row(table->record[1], new_data);
+    {
+      /*
+        We have to do the memcmp as otherwise we may get error 169 from InnoDB
+      */
+      if (memcmp(table->record[0], table->record[1], table->s->reclength))
+        error= update_row(table->record[1], new_data);
+    }
     end_error= ha_rnd_end();
     if (!error)
       error= end_error;