Bug#37016: TRUNCATE TABLE removes some rows but not all

The special TRUNCATE TABLE (DDL) transaction wasn't being properly
rolled back if a error occurred during row by row deletion. The
error can be caused by a foreign key restriction imposed by InnoDB
SE and would cause the server to erroneously issue a implicit
commit.

The solution is to rollback the transaction if a truncation via row
by row deletion fails, otherwise commit. All effects of a TRUNCATE 
ABLE operation are rolled back if a row by row deletion fails.

mysql-test/include/commit.inc:
  Truncate always starts a transaction and commits at the end.
  The commit at the end increases the count by two, one is the
  storage engine commit and the other is the binary log.
mysql-test/r/commit_1innodb.result:
  Update test case results.
mysql-test/r/innodb_mysql.result:
  Update test case results.
mysql-test/t/innodb_mysql.test:
  Add test case for Bug#37016
sql/sql_delete.cc:
  Move truncation using row by row deletion to its own function.
  If row by row deletion fails, rollback the transaction.
  
  Remove the meddling with disabling and enabling of autocommit
  as TRUNCATE transaction is now explicitly ended (committed
  or rolled back).

mysql-test/include/commit.inc

@@ -617,10 +617,10 @@ call p_verify_status_increment(0, 0, 0, 0);
 --echo
 --echo # No test because of Bug#8729 "rename table fails on temporary table"
 
---echo # 24. DDL: TRUNCATE TEMPORARY TABLE, does not start a transaction
+--echo # 24. DDL: TRUNCATE TEMPORARY TABLE
 --echo
 truncate table t2;
-call p_verify_status_increment(2, 0, 2, 0);
+call p_verify_status_increment(4, 0, 4, 0);
 commit;
 --echo # There is nothing left to commit
 call p_verify_status_increment(0, 0, 0, 0);
@@ -733,7 +733,7 @@ call p_verify_status_increment(1, 0, 1, 0);
 rename table t4 to t3;
 call p_verify_status_increment(1, 0, 1, 0);
 truncate table t3;
-call p_verify_status_increment(2, 2, 2, 2);
+call p_verify_status_increment(4, 4, 2, 2);
 create view v1 as select * from t2;
 call p_verify_status_increment(1, 0, 1, 0);
 check table t1;

mysql-test/r/commit_1innodb.result

@@ -683,10 +683,10 @@ SUCCESS
 # 23. DDL: RENAME TEMPORARY TABLE, does not start a transaction
 
 # No test because of Bug#8729 "rename table fails on temporary table"
-# 24. DDL: TRUNCATE TEMPORARY TABLE, does not start a transaction
+# 24. DDL: TRUNCATE TEMPORARY TABLE
 
 truncate table t2;
-call p_verify_status_increment(2, 0, 2, 0);
+call p_verify_status_increment(4, 0, 4, 0);
 SUCCESS
 
 commit;
@@ -853,7 +853,7 @@ call p_verify_status_increment(1, 0, 1, 0);
 SUCCESS
 
 truncate table t3;
-call p_verify_status_increment(2, 2, 2, 2);
+call p_verify_status_increment(4, 4, 2, 2);
 SUCCESS
 
 create view v1 as select * from t2;

mysql-test/r/innodb_mysql.result

@@ -1788,4 +1788,62 @@ DEALLOCATE PREPARE stmt1;
 DEALLOCATE PREPARE stmt3;
 DROP TABLE t1,t3,t2;
 DROP FUNCTION f1;
+DROP TABLE IF EXISTS t1,t2;
+CREATE TABLE t1 (id INT NOT NULL, PRIMARY KEY (id)) ENGINE=INNODB;
+CREATE TABLE t2 (id INT PRIMARY KEY,
+t1_id INT, INDEX par_ind (t1_id),
+FOREIGN KEY (t1_id) REFERENCES t1(id)) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1),(2);
+INSERT INTO t2 VALUES (3,2);
+SET AUTOCOMMIT = 0;
+START TRANSACTION;
+TRUNCATE TABLE t1;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
+SELECT * FROM t1;
+id
+1
+2
+COMMIT;
+SELECT * FROM t1;
+id
+1
+2
+START TRANSACTION;
+TRUNCATE TABLE t1;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
+SELECT * FROM t1;
+id
+1
+2
+ROLLBACK;
+SELECT * FROM t1;
+id
+1
+2
+SET AUTOCOMMIT = 1;
+START TRANSACTION;
+SELECT * FROM t1;
+id
+1
+2
+COMMIT;
+TRUNCATE TABLE t1;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
+SELECT * FROM t1;
+id
+1
+2
+DELETE FROM t2 WHERE id = 3;
+START TRANSACTION;
+SELECT * FROM t1;
+id
+1
+2
+TRUNCATE TABLE t1;
+ROLLBACK;
+SELECT * FROM t1;
+id
+TRUNCATE TABLE t2;
+DROP TABLE t2;
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/innodb_mysql.test

@@ -132,4 +132,56 @@ DEALLOCATE PREPARE stmt3;
 DROP TABLE t1,t3,t2;
 DROP FUNCTION f1;
 
+#
+# Bug#37016: TRUNCATE TABLE removes some rows but not all
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1,t2;
+--enable_warnings
+
+CREATE TABLE t1 (id INT NOT NULL, PRIMARY KEY (id)) ENGINE=INNODB;
+CREATE TABLE t2 (id INT PRIMARY KEY,
+                 t1_id INT, INDEX par_ind (t1_id),
+                 FOREIGN KEY (t1_id) REFERENCES t1(id)) ENGINE=INNODB;
+INSERT INTO t1 VALUES (1),(2);
+INSERT INTO t2 VALUES (3,2);
+
+SET AUTOCOMMIT = 0;
+
+START TRANSACTION;
+--error ER_ROW_IS_REFERENCED_2
+TRUNCATE TABLE t1;
+SELECT * FROM t1;
+COMMIT;
+SELECT * FROM t1;
+
+START TRANSACTION;
+--error ER_ROW_IS_REFERENCED_2
+TRUNCATE TABLE t1;
+SELECT * FROM t1;
+ROLLBACK;
+SELECT * FROM t1;
+
+SET AUTOCOMMIT = 1;
+
+START TRANSACTION;
+SELECT * FROM t1;
+COMMIT;
+
+--error ER_ROW_IS_REFERENCED_2
+TRUNCATE TABLE t1;
+SELECT * FROM t1;
+DELETE FROM t2 WHERE id = 3;
+
+START TRANSACTION;
+SELECT * FROM t1;
+TRUNCATE TABLE t1;
+ROLLBACK;
+SELECT * FROM t1;
+TRUNCATE TABLE t2;
+
+DROP TABLE t2;
+DROP TABLE t1;
+
 --echo End of 5.1 tests

sql/sql_delete.cc

@@ -950,6 +950,26 @@ bool multi_delete::send_eof()
   TRUNCATE TABLE
 ****************************************************************************/
 
+/*
+  Row-by-row truncation if the engine does not support table recreation.
+  Probably a InnoDB table.
+*/
+
+static bool mysql_truncate_by_delete(THD *thd, TABLE_LIST *table_list)
+{
+  bool error, save_binlog_row_based= thd->current_stmt_binlog_row_based;
+  DBUG_ENTER("mysql_truncate_by_delete");
+  table_list->lock_type= TL_WRITE;
+  mysql_init_select(thd->lex);
+  thd->clear_current_stmt_binlog_row_based();
+  error= mysql_delete(thd, table_list, NULL, NULL, HA_POS_ERROR, LL(0), TRUE);
+  ha_autocommit_or_rollback(thd, error);
+  end_trans(thd, error ? ROLLBACK : COMMIT);
+  thd->current_stmt_binlog_row_based= save_binlog_row_based;
+  DBUG_RETURN(error);
+}
+
+
 /*
   Optimize delete of all rows by doing a full generate of the table
   This will work even if the .ISM and .ISD tables are destroyed
@@ -1055,24 +1075,6 @@ bool mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
   DBUG_RETURN(error);
 
 trunc_by_del:
-  /* Probably InnoDB table */
-  ulonglong save_options= thd->options;
-  table_list->lock_type= TL_WRITE;
-  thd->options&= ~(OPTION_BEGIN | OPTION_NOT_AUTOCOMMIT);
-  ha_enable_transaction(thd, FALSE);
-  mysql_init_select(thd->lex);
-  bool save_binlog_row_based= thd->current_stmt_binlog_row_based;
-  thd->clear_current_stmt_binlog_row_based();
-  error= mysql_delete(thd, table_list, (COND*) 0, (SQL_LIST*) 0,
-                      HA_POS_ERROR, LL(0), TRUE);
-  ha_enable_transaction(thd, TRUE);
-  /*
-    Safety, in case the engine ignored ha_enable_transaction(FALSE)
-    above. Also clears thd->transaction.*.
-  */
-  error= ha_autocommit_or_rollback(thd, error);
-  ha_commit(thd);
-  thd->options= save_options;
-  thd->current_stmt_binlog_row_based= save_binlog_row_based;
+  error= mysql_truncate_by_delete(thd, table_list);
   DBUG_RETURN(error);
 }