MDEV-9667: Server hangs after select count(distinct name) from t2 where a=8366 and b>=5 and b<=5;

In row_search_for_mysql function on XtraDB there was a old logic
where null bytes were inited. This caused server to think that
key value is null and continue on incorrect path.

1 files changed, 21 insertions, 0 deletions

diff --git a/mysql-test/suite/innodb/r/innodb-agregate.result b/mysql-test/suite/innodb/r/innodb-agregate.result
new file mode 100644
index 00000000000..d3e096c7eb0
--- /dev/null
+++ b/mysql-test/suite/innodb/r/innodb-agregate.result
@@ -0,0 +1,21 @@
+create table t2 (a smallint(6) not null, b int(10) not null, name varchar(20), primary key(a,b), key(name)) engine=InnoDB;
+insert into t2 values (8355,3,"sanja"),(8355,4,"wlad"),(8366,5, "lawrin"),(8366,6,"markusjm");
+select count(distinct name) from t2 where a=8366 and b>=5 and b<=5;
+count(distinct name)
+1
+select count(distinct name) from t2 where a=8366 and b=5;
+count(distinct name)
+1
+select count(distinct name) from t2 where a=8366 and b between 5 and 5.5;
+count(distinct name)
+1
+select sum(distinct a) from t2 where a=8366 and b>=5 and b<=5;
+sum(distinct a)
+8366
+select sum(distinct a) from t2 where a=8366 and b=5;
+sum(distinct a)
+8366
+select sum(distinct a) from t2 where a=8366 and b between 5 and 5.5;
+sum(distinct a)
+8366
+drop table t2;