Fix bug #11946, truncate not always resetting the auto-increment counter

in InnoDB tables.


mysql-test/r/innodb.result:
  New tests.
mysql-test/t/innodb.test:
  New tests.
sql/ha_innodb.cc:
  Add reset_auto_increment.
sql/ha_innodb.h:
  Add reset_auto_increment.
sql/handler.h:
  Add reset_auto_increment.
sql/sql_delete.cc:
  Call handler->reset_auto_increment when needed.

1 files changed, 23 insertions, 0 deletions

diff --git a/mysql-test/r/innodb.result b/mysql-test/r/innodb.result
index 69620d5d527..b2c78560562 100644
--- a/mysql-test/r/innodb.result
+++ b/mysql-test/r/innodb.result
@@ -2483,3 +2483,26 @@ delete t1 from t1,t2 where f1=f3 and f4='cc';
 select * from t1;
 f1	f2
 drop table t1,t2;
+CREATE TABLE t1 (
+id INTEGER NOT NULL AUTO_INCREMENT, PRIMARY KEY (id)
+) ENGINE=InnoDB;
+CREATE TABLE t2 (
+id INTEGER NOT NULL,
+FOREIGN KEY (id) REFERENCES t1 (id)
+) ENGINE=InnoDB;
+INSERT INTO t1 (id) VALUES (NULL);
+SELECT * FROM t1;
+id
+1
+TRUNCATE t1;
+INSERT INTO t1 (id) VALUES (NULL);
+SELECT * FROM t1;
+id
+1
+DELETE FROM t1;
+TRUNCATE t1;
+INSERT INTO t1 (id) VALUES (NULL);
+SELECT * FROM t1;
+id
+1
+DROP TABLE t2, t1;