Fix for bug#16901 Partitions: crash, SELECT, column of part. function=first column of primary key

  use part_info->no_subparts to calculate partition range in case of subpartitions

mysql-test/r/partition.result

@@ -278,3 +278,14 @@ partition p1 values in (14)
 insert into t1 values (10,1);
 ERROR HY000: Table has no partition for value 11
 drop table t1;
+create table t1 (f1 integer,f2 integer, f3 varchar(10), primary key(f1,f2))
+partition by range(f1) subpartition by hash(f2) subpartitions 2
+(partition p1 values less than (0),
+partition p2 values less than (2),
+partition p3 values less than (2147483647));
+insert into t1 values(10,10,'10');
+insert into t1 values(2,2,'2');
+select * from t1 where f1 = 2;
+f1	f2	f3
+2	2	2
+drop table t1;

mysql-test/t/partition.test

@@ -353,3 +353,18 @@ insert into t1 values (10,1);
 
 drop table t1;
 
+#
+# Bug#16901 Partitions: crash, SELECT, column of part.
+#           function=first column of primary key
+#
+create table t1 (f1 integer,f2 integer, f3 varchar(10), primary key(f1,f2))
+partition by range(f1) subpartition by hash(f2) subpartitions 2
+(partition p1 values less than (0),
+ partition p2 values less than (2),
+ partition p3 values less than (2147483647));
+
+insert into t1 values(10,10,'10');
+insert into t1 values(2,2,'2');
+select * from t1 where f1 = 2;
+drop table t1;
+

sql/sql_partition.cc

@@ -3754,7 +3754,7 @@ void get_partition_set(const TABLE *table, byte *buf, const uint index,
         subpartitions. This is a range without holes.
       */
       DBUG_ASSERT(sub_part == no_parts);
-      part_spec->start_part= part_part * part_info->no_parts;
+      part_spec->start_part= part_part * part_info->no_subparts;
       part_spec->end_part= part_spec->start_part+part_info->no_subparts - 1;
     }
     else