BUG#665669: Result differences on query re-execution

- Cause: handler::in_range_check_pushed_down was not reset when a 
  command would call handler->idx_cond_push() without later calling
  handler->index_end().
- Fix: reset the variable in handler->reset(), too (like we do with other
  Index Condition Pushdown members).

mysql-test/r/innodb_mrr.result

@@ -660,3 +660,24 @@ count(*)	sum(table1.col_int_key*table2.pk)
 drop table t1,t2;
 set join_cache_level=@my_save_join_cache_level;
 set join_buffer_size=@my_save_join_buffer_size;
+#
+# BUG#665669: Result differences on query re-execution
+#
+create table t1 (pk int primary key, b int, c int default 0, index idx(b)) engine=innodb;
+insert into t1(pk,b) values (3, 30), (2, 20), (9, 90), (7, 70), (4, 40), (5, 50), (10, 100), (12, 120);
+set @my_save_optimizer_use_mrr=@@optimizer_use_mrr;
+set optimizer_use_mrr='disable';
+explain select * from t1 where b > 1000;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	idx	idx	5	NULL	1	Using index condition
+# The following two must produce indentical results:
+select * from t1 where pk < 2 or pk between 3 and 4;
+pk	b	c
+3	30	0
+4	40	0
+select * from t1 where pk < 2 or pk between 3 and 4;
+pk	b	c
+3	30	0
+4	40	0
+drop table t1;
+set optimizer_use_mrr = @my_save_optimizer_use_mrr;

mysql-test/t/innodb_mrr.test

@@ -364,3 +364,18 @@ drop table t1,t2;
 set join_cache_level=@my_save_join_cache_level;
 set join_buffer_size=@my_save_join_buffer_size;
 
+
+--echo #
+--echo # BUG#665669: Result differences on query re-execution
+--echo #
+create table t1 (pk int primary key, b int, c int default 0, index idx(b)) engine=innodb;
+insert into t1(pk,b) values (3, 30), (2, 20), (9, 90), (7, 70), (4, 40), (5, 50), (10, 100), (12, 120);
+set @my_save_optimizer_use_mrr=@@optimizer_use_mrr;
+set optimizer_use_mrr='disable';
+explain select * from t1 where b > 1000;
+--echo # The following two must produce indentical results:
+select * from t1 where pk < 2 or pk between 3 and 4;
+select * from t1 where pk < 2 or pk between 3 and 4;   
+drop table t1;
+set optimizer_use_mrr = @my_save_optimizer_use_mrr;
+

storage/maria/ha_maria.cc

@@ -2456,6 +2456,7 @@ int ha_maria::reset(void)
 {
   pushed_idx_cond= NULL;
   pushed_idx_cond_keyno= MAX_KEY;
+  in_range_check_pushed_down= FALSE;
   ma_set_index_cond_func(file, NULL, 0);
   ds_mrr.dsmrr_close();
   if (file->trn)

storage/myisam/ha_myisam.cc

@@ -1929,6 +1929,7 @@ int ha_myisam::reset(void)
 {
   pushed_idx_cond= NULL;
   pushed_idx_cond_keyno= MAX_KEY;
+  in_range_check_pushed_down= FALSE;
   mi_set_index_cond_func(file, NULL, 0);
   ds_mrr.dsmrr_close();
   return mi_reset(file);

storage/xtradb/handler/ha_innodb.cc

@@ -8865,6 +8865,7 @@ ha_innobase::extra(
                         pushed_idx_cond= FALSE;
                         pushed_idx_cond_keyno= MAX_KEY;
                         prebuilt->idx_cond_func= NULL;
+                        in_range_check_pushed_down= FALSE;
 			break;
 		case HA_EXTRA_NO_KEYREAD:
 			prebuilt->read_just_key = 0;
@@ -8915,6 +8916,7 @@ ha_innobase::reset()
 	/* Reset index condition pushdown state */
 	pushed_idx_cond_keyno= MAX_KEY;
 	pushed_idx_cond= NULL;
+        in_range_check_pushed_down= FALSE;
 	ds_mrr.dsmrr_close();
 	prebuilt->idx_cond_func= NULL;