# MDEV-476: Cassandra: Server crashes in calculate_key_len on DELETE with ORDER BY

- Fix typo in ha_cassandra::rnd_pos().
- in ::index_read_map(), do not assume that pk column is part of table->read_set.

mysql-test/r/cassandra.result

@@ -59,3 +59,11 @@ rowkey11	data1-value2	34543
 rowkey10	data1-value	123456
 delete from t1;
 drop table t1;
+#
+# MDEV-476: Cassandra: Server crashes in calculate_key_len on DELETE with ORDER BY
+#
+CREATE TABLE t1 (rowkey BIGINT PRIMARY KEY, a BIGINT) ENGINE=CASSANDRA
+thrift_host='localhost' keyspace='mariadbtest2' column_family = 'cf2';
+INSERT INTO t1 VALUES (1,1),(2,2);
+DELETE FROM t1 ORDER BY a LIMIT 1;
+DROP TABLE t1;

mysql-test/t/cassandra.test

@@ -43,6 +43,8 @@ CREATE KEYSPACE mariadbtest2
 USE mariadbtest2;
 create columnfamily cf1 ( pk varchar primary key, data1 varchar, data2 bigint);
 
+create columnfamily cf2 (rowkey bigint primary key, a bigint);
+
 --enable_parsing
 ############################################################################
 ## Cassandra initialization ends
@@ -96,6 +98,17 @@ select * from t1 order by data2;
 delete from t1;
 drop table t1;
 
+--echo #
+--echo # MDEV-476: Cassandra: Server crashes in calculate_key_len on DELETE with ORDER BY
+--echo #
+CREATE TABLE t1 (rowkey BIGINT PRIMARY KEY, a BIGINT) ENGINE=CASSANDRA
+  thrift_host='localhost' keyspace='mariadbtest2' column_family = 'cf2';
+
+INSERT INTO t1 VALUES (1,1),(2,2);
+DELETE FROM t1 ORDER BY a LIMIT 1;
+
+DROP TABLE t1;
+
 ############################################################################
 ## Cassandra cleanup
 ############################################################################

storage/cassandra/ha_cassandra.cc

@@ -645,8 +645,14 @@ int ha_cassandra::index_read_map(uchar *buf, const uchar *key,
 
   char *cass_key;
   int cass_key_len;
+  my_bitmap_map *old_map;
+
+  old_map= dbug_tmp_use_all_columns(table, table->read_set);
+
   rowkey_converter->mariadb_to_cassandra(&cass_key, &cass_key_len);
 
+  dbug_tmp_restore_column_map(table->read_set, old_map);
+
   bool found;
   if (se->get_slice(cass_key, cass_key_len, &found))
   {
@@ -879,6 +885,7 @@ int ha_cassandra::rnd_pos(uchar *buf, uchar *pos)
   DBUG_ENTER("ha_cassandra::rnd_pos");
   
   int save_active_index= active_index;
+  active_index= 0; /* The primary key */
   rc= index_read_map(buf, pos, key_part_map(1), HA_READ_KEY_EXACT);
 
   active_index= save_active_index;