BUG #16810: Error on coalesce partition

New test case (bug was already fixed)

mysql-test/r/ndb_partition_key.result

@@ -89,3 +89,16 @@ ALTER TABLE t1
 PARTITION BY KEY(a)
 (PARTITION p0 ENGINE = NDB, PARTITION p1 ENGINE = NDB);
 drop table t1;
+CREATE TABLE t1 (
+c1 MEDIUMINT NOT NULL AUTO_INCREMENT,
+c2 TEXT NOT NULL,
+c3 INT NOT NULL,
+c4 BIT NOT NULL,
+c5 FLOAT,
+c6 VARCHAR(255),
+c7 TIMESTAMP,
+PRIMARY KEY(c1,c3))
+ENGINE=NDB
+PARTITION BY KEY(c3) PARTITIONS 5;
+ALTER TABLE t1 COALESCE PARTITION 4;
+DROP TABLE t1;