Fix for bug#16907 Partitions: crash, SELECT goes into last partition, UNIQUE INDEX

  In presense of subpartitioning use get_part_partition_id() to calculate part_id

mysql-test/r/partition.result

@@ -289,3 +289,14 @@ select * from t1 where f1 = 2;
 f1	f2	f3
 2	2	2
 drop table t1;
+create table t1 (f1 integer,f2 integer, unique index(f1))
+partition by range(f1 div 2)
+subpartition by hash(f1) subpartitions 2
+(partition partb values less than (2),
+partition parte values less than (4),
+partition partf values less than (10000));
+insert into t1 values(10,1);
+select * from t1 where f1 = 10;
+f1	f2
+10	1
+drop table t1;

mysql-test/t/partition.test

@@ -368,3 +368,15 @@ insert into t1 values(2,2,'2');
 select * from t1 where f1 = 2;
 drop table t1;
 
+#
+# Bug #16907 Partitions: crash, SELECT goes into last partition, UNIQUE INDEX
+#
+create table t1 (f1 integer,f2 integer, unique index(f1))
+partition by range(f1 div 2)
+subpartition by hash(f1) subpartitions 2
+(partition partb values less than (2),
+partition parte values less than (4),
+partition partf values less than (10000));
+insert into t1 values(10,1);
+select * from t1 where f1 = 10;
+drop table t1;

sql/sql_partition.cc

@@ -6009,7 +6009,10 @@ static uint32 get_next_partition_via_walking(PARTITION_ITERATOR *part_iter)
     field->store(part_iter->field_vals.start, FALSE);
     part_iter->field_vals.start++;
     longlong dummy;
-    if (!part_iter->part_info->get_partition_id(part_iter->part_info, 
+    if (is_sub_partitioned(part_iter->part_info) &&
+        !part_iter->part_info->get_part_partition_id(part_iter->part_info,
+                                                     &part_id, &dummy) ||
+        !part_iter->part_info->get_partition_id(part_iter->part_info,
                                                 &part_id, &dummy))
       return part_id;
   }