sql_mode=ORACLE: Syntax error in a OPEN cursor with parameters makes the server crash

SET sql_mode=oracle;

DROP TABLE IF EXISTS t1;

CREATE TABLE t1 (a INT, b VARCHAR(10));

INSERT INTO t1 VALUES (1,'A');

DROP PROCEDURE IF EXISTS p1;

CREATE TABLE t1 (a INT, b VARCHAR(10));

DELIMITER $$

CREATE PROCEDURE p1(a INT,b VARCHAR)

AS

  CURSOR c (p_a INT, p_b VARCHAR) IS SELECT * FROM t1 WHERE a=p_a;

BEGIN

  OPEN c(a+, b);

  LOOP

    FETCH c INTO a, b;

    EXIT WHEN c%NOTFOUND;

    SELECT a, b;

  END LOOP;

  CLOSE c;

END;

$$

DELIMITER ;

CALL p1(1,'a');

DROP TABLE t1;