BUG#629684: Unreachable code in multi_range_read.cc in maria-5.3-dsmrr-cpk

- More test coverage

mysql-test/r/myisam_mrr.result

@@ -413,4 +413,27 @@ explain select * from t1 where a < 20;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	a	a	5	NULL	20	Using index condition; Using MRR
 set optimizer_switch=@save_optimizer_switch;
+# 
+# BUG#629684: Unreachable code in multi_range_read.cc in maria-5.3-dsmrr-cpk
+#
+delete from t0 where a > 2;
+insert into t0 values (NULL),(NULL);
+insert into t1 values (NULL, 1234), (NULL, 5678);
+set @save_join_cache_level=@@join_cache_level;
+set @@join_cache_level=6;
+explain 
+select * from t0, t1 where t0.a<=>t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	5	
+1	SIMPLE	t1	ref	a	a	5	test.t0.a	1	Using index condition(BKA); Using join buffer
+select * from t0, t1 where t0.a<=>t1.a;
+a	a	b
+0	0	0
+1	1	1
+2	2	2
+NULL	NULL	1234
+NULL	NULL	1234
+NULL	NULL	5678
+NULL	NULL	5678
+set @@join_cache_level=@save_join_cache_level;
 drop table t0, t1;

mysql-test/t/myisam_mrr.test

@@ -123,4 +123,20 @@ explain select * from t1 where a < 20;
 
 set optimizer_switch=@save_optimizer_switch;
 
+
+--echo # 
+--echo # BUG#629684: Unreachable code in multi_range_read.cc in maria-5.3-dsmrr-cpk
+--echo #
+
+delete from t0 where a > 2;
+insert into t0 values (NULL),(NULL);
+insert into t1 values (NULL, 1234), (NULL, 5678);
+
+set @save_join_cache_level=@@join_cache_level;
+set @@join_cache_level=6;
+explain 
+select * from t0, t1 where t0.a<=>t1.a;
+select * from t0, t1 where t0.a<=>t1.a;
+
+set @@join_cache_level=@save_join_cache_level;
 drop table t0, t1;