In branch 3.2-georg of Connector/C I tried to remove a COM_STMT_CLOSE before reusing a statement with mariadb_stmt_execute_direct, which ends up in strange behavior, since the previously executed statement was executed again.

From general log:

10882 Prepare  DROP TABLE IF EXISTS bulk_null

10882 Execute  DROP TABLE IF EXISTS bulk_null

10882 Prepare  CREATE TABLE bulk_null (a int not null auto_increment primary key, b varchar(20))

10882 Execute  DROP TABLE IF EXISTS bulk_null

How to repeat:
Checkout branch 3.2-georg of Connector/C, build and run bulk1 test.

If I replace execute_direct api calls by mysql_stmt_prepare and mysql_stmt_execute it works as expected.