branches/5.1: Copy the maximum AUTOINC value from the old table to the new

table when MySQL does a CREATE INDEX ON T. This is required because MySQL
does a table copy, rename and drops the old table.
Fix Bug#47125: auto_increment start value is ignored if an index is created and engine=innodb
rb://168

handler/ha_innodb.cc

@@ -5510,18 +5510,22 @@ ha_innobase::create(
 	setup at this stage and so we use thd. */
 
 	/* We need to copy the AUTOINC value from the old table if
-	this is an ALTER TABLE. */
+	this is an ALTER TABLE or CREATE INDEX because CREATE INDEX
+	does a table copy too. */
 
 	if (((create_info->used_fields & HA_CREATE_USED_AUTO)
-	    || thd_sql_command(thd) == SQLCOM_ALTER_TABLE)
-	    && create_info->auto_increment_value != 0) {
-
-		/* Query was ALTER TABLE...AUTO_INCREMENT = x; or
-		CREATE TABLE ...AUTO_INCREMENT = x; Find out a table
-		definition from the dictionary and get the current value
-		of the auto increment field. Set a new value to the
-		auto increment field if the value is greater than the
-		maximum value in the column. */
+	    || thd_sql_command(thd) == SQLCOM_ALTER_TABLE
+	    || thd_sql_command(thd) == SQLCOM_CREATE_INDEX)
+	    && create_info->auto_increment_value > 0) {
+
+		/* Query was one of :
+		CREATE TABLE ...AUTO_INCREMENT = x; or
+		ALTER TABLE...AUTO_INCREMENT = x;   or
+		CREATE INDEX x on t(...);
+		Find out a table definition from the dictionary and get
+		the current value of the auto increment field. Set a new
+		value to the auto increment field if the value is greater
+		than the maximum value in the column. */
 
 		auto_inc_value = create_info->auto_increment_value;
 

mysql-test/innodb-autoinc.result

@@ -1111,3 +1111,18 @@ c1	c2
 3	innodb
 4	NULL
 DROP TABLE t1;
+CREATE TABLE T1 (c1 INT AUTO_INCREMENT, c2 INT, PRIMARY KEY(c1)) AUTO_INCREMENT=10 ENGINE=InnoDB;
+CREATE INDEX i1 on T1(c2);
+SHOW CREATE TABLE T1;
+Table	Create Table
+T1	CREATE TABLE `T1` (
+  `c1` int(11) NOT NULL AUTO_INCREMENT,
+  `c2` int(11) DEFAULT NULL,
+  PRIMARY KEY (`c1`),
+  KEY `i1` (`c2`)
+) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=latin1
+INSERT INTO T1 (c2) values (0);
+SELECT * FROM T1;
+c1	c2
+10	0
+DROP TABLE T1;

mysql-test/innodb-autoinc.test

@@ -607,5 +607,16 @@ INSERT INTO t1 VALUES (NULL, NULL);
 SHOW CREATE TABLE t1;
 SELECT * FROM t1;
 DROP TABLE t1;
-
+#
 # End negative number check
+
+##
+# 47125: auto_increment start value is ignored if an index is created
+# and engine=innodb
+#
+CREATE TABLE T1 (c1 INT AUTO_INCREMENT, c2 INT, PRIMARY KEY(c1)) AUTO_INCREMENT=10 ENGINE=InnoDB;
+CREATE INDEX i1 on T1(c2);
+SHOW CREATE TABLE T1;
+INSERT INTO T1 (c2) values (0);
+SELECT * FROM T1;
+DROP TABLE T1;