MDEV-10325: Queries examines all rows of a tables when it should not

The problem was introduced by 1859caf60b725f81f2ac6091eb44cb848a4a439a:
  MDEV-10175: range optimizer calls records_in_range() for full extended keys

  Make the range optimizer not call records_in_range() when it would
  not give any benefit.

that patch used an incorrect way to check for full extended key. Now fixing
the check.

1 files changed, 28 insertions, 0 deletions

diff --git a/mysql-test/t/innodb_ext_key.test b/mysql-test/t/innodb_ext_key.test
index 9f3a89ff948..ec774b638e8 100644
--- a/mysql-test/t/innodb_ext_key.test
+++ b/mysql-test/t/innodb_ext_key.test
@@ -693,5 +693,33 @@ drop table t1, t2;
 
 set optimizer_switch=@save_optimizer_switch;
 
+--echo # 
+--echo # MDEV-10325: Queries examines all rows of a tables when it should not
+--echo # 
+create table t0 (a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t1 (
+  pk int not null,
+  col1 varchar(32),
+  filler varchar(100),
+  key idx1(col1(10)),
+  primary key (pk)
+)engine=innodb;
+
+insert into t1 
+select
+  A.a + 10*B.a + 100*C.a,
+  concat('1234567890-', 1000+ A.a + 10*B.a + 100*C.a),
+  repeat('filler-data-', 4)
+from 
+  t0 A, t0 B, t0 C;
+
+--echo # The following must use type=ALL (and NOT type=ref, rows=1)
+--replace_column 9 #
+explain select * from t1 where col1='1234567890-a';
+
+drop table t0,t1;
+
 set optimizer_switch=@save_ext_key_optimizer_switch;
 SET SESSION STORAGE_ENGINE=DEFAULT;