MDEV-22277 LeakSanitizer: detected memory leaks in mem_heap_create_bl…

…ock_func after attempt to create foreign key

- During online DDL, prepare phase error handler fails to remove
the memory allocated for newly created foreign keys.

mysql-test/suite/innodb/r/foreign_key.result

@@ -233,3 +233,14 @@ Opened_table_definitions	2
 Opened_tables	2
 drop function foo;
 drop table t2, t1;
+CREATE TABLE t1 (pk INT, a INT, PRIMARY KEY (pk)) ENGINE=InnoDB;
+XA START 'xid';
+INSERT INTO t1 VALUES (1,2);
+CREATE TABLE x AS SELECT * FROM t1;
+ERROR XAE07: XAER_RMFAIL: The command cannot be executed when global transaction is in the  ACTIVE state
+SET foreign_key_checks= OFF, innodb_lock_wait_timeout= 1;
+ALTER TABLE t1 ADD FOREIGN KEY f (a) REFERENCES t1 (pk), LOCK=EXCLUSIVE;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+XA END 'xid';
+XA ROLLBACK 'xid';
+DROP TABLE t1;

mysql-test/suite/innodb/t/foreign_key.test

@@ -285,6 +285,20 @@ show status like '%opened_tab%';
 drop function foo;
 drop table t2, t1;
 
+CREATE TABLE t1 (pk INT, a INT, PRIMARY KEY (pk)) ENGINE=InnoDB;
+XA START 'xid';
+INSERT INTO t1 VALUES (1,2);
+--error ER_XAER_RMFAIL
+CREATE TABLE x AS SELECT * FROM t1;
+--connect (con1,localhost,root,,test)
+SET foreign_key_checks= OFF, innodb_lock_wait_timeout= 1;
+--error ER_LOCK_WAIT_TIMEOUT
+ALTER TABLE t1 ADD FOREIGN KEY f (a) REFERENCES t1 (pk), LOCK=EXCLUSIVE;# Cleanup
+--disconnect con1
+--connection default
+XA END 'xid';
+XA ROLLBACK 'xid';
+DROP TABLE t1;
 #
 # End of 10.1 tests
 #

storage/innobase/handler/handler0alter.cc

@@ -3376,6 +3376,12 @@ prepare_inplace_alter_table_dict(
 	trx_free_for_mysql(ctx->trx);
 	trx_commit_for_mysql(ctx->prebuilt->trx);
 
+	for (uint i = 0; i < ctx->num_to_add_fk; i++) {
+		if (ctx->add_fk[i]) {
+			dict_foreign_free(ctx->add_fk[i]);
+		}
+	}
+
 	delete ctx;
 	ha_alter_info->handler_ctx = NULL;
 

storage/xtradb/handler/handler0alter.cc

@@ -3388,6 +3388,12 @@ prepare_inplace_alter_table_dict(
 	trx_free_for_mysql(ctx->trx);
 	trx_commit_for_mysql(ctx->prebuilt->trx);
 
+	for (uint i = 0; i < ctx->num_to_add_fk; i++) {
+		if (ctx->add_fk[i]) {
+			dict_foreign_free(ctx->add_fk[i]);
+		}
+	}
+
 	delete ctx;
 	ha_alter_info->handler_ctx = NULL;