BUG#18659: In get_part_iter_for_interval_via_walking(), when we need to

obtain partition number, call partition_info->get_part_partition_id() when
the table has subpartitions, and get_partition_id() otherwise. (The bug
was that we were always doing the latter)


mysql-test/r/partition_pruning.result:
  Testcase for BUG#18659
mysql-test/t/partition_pruning.test:
  Testcase for BUG#18659

1 files changed, 14 insertions, 0 deletions

diff --git a/mysql-test/t/partition_pruning.test b/mysql-test/t/partition_pruning.test
index 25320e9f80d..63d389f2c06 100644
--- a/mysql-test/t/partition_pruning.test
+++ b/mysql-test/t/partition_pruning.test
@@ -479,5 +479,19 @@ select * from t1 where a>='a' and a <= 'dddd';
 explain partitions select * from t1 where a>='a' and a <= 'dddd';
 drop table t1;
 
+# BUG#18659: Assertion failure when subpartitioning is used and partition is
+# "IS NULL"
+create table t1 (f_int1 integer) partition by list(abs(mod(f_int1,2)))
+  subpartition by hash(f_int1) subpartitions 2
+(
+  partition part1 values in (0),
+  partition part2 values in (1),
+  partition part4 values in (null)
+);
+insert into t1 set f_int1 = null;
+
+select * from t1 where f_int1 is null;
+explain partitions select * from t1 where f_int1 is null;
+
 # No tests for NULLs in RANGE(monotonic_expr()) - they depend on BUG#15447
 # being fixed.