MDEV-19820 Wrong result with multiple single column index request

The bug occured when the optimizer decided to use a rowid filter built
by a range index scan to access an InnoDB table with generated clustered
index.
When a table is accessed by a secondary index Idx employing a rowid filter the
the value of pk contained in the found index tuple is checked against the
filter. A call of the handler function position is supposed to put the
pk value into the handler::ref buffer. However for generated clustered
primary keys it did not happened. The patch fixes this problem.

mysql-test/main/rowid_filter_innodb.result

@@ -2162,4 +2162,51 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1003	select 1 AS `id`,`test`.`t2`.`y` AS `y`,`test`.`t2`.`x` AS `x` from `test`.`t1` join `test`.`t2` where `test`.`t2`.`y` = 2 and `test`.`t2`.`x` = 1
 drop table t1, t2;
+#
+# MDEV-19820: use of rowid filter for innodb table without primary key
+#
+create table t1 (a int, b int, key (b), key (a)) engine=innodb;
+insert into t1
+select (rand(1)*1000)/10, (rand(1001)*1000)/50 from seq_1_to_1000;
+analyze table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	OK
+set @save_optimizer_switch= @@optimizer_switch;
+set optimizer_switch='rowid_filter=off';
+select count(*) from t1 where a in (22,83,11) and b=2;
+count(*)
+6
+explain extended select count(*) from t1 where a in (22,83,11) and b=2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ref	b,a	b	5	const	59	55.93	Using where
+Warnings:
+Note	1003	select count(0) AS `count(*)` from `test`.`t1` where `test`.`t1`.`b` = 2 and `test`.`t1`.`a` in (22,83,11)
+select * from t1 where a in (22,83,11) and b=2;
+a	b
+11	2
+11	2
+83	2
+11	2
+83	2
+22	2
+set optimizer_switch='rowid_filter=on';
+select count(*) from t1 where a in (22,83,11) and b=2;
+count(*)
+6
+explain extended select count(*) from t1 where a in (22,83,11) and b=2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ref|filter	b,a	b|a	5|5	const	59 (3%)	55.93	Using where; Using rowid filter
+Warnings:
+Note	1003	select count(0) AS `count(*)` from `test`.`t1` where `test`.`t1`.`b` = 2 and `test`.`t1`.`a` in (22,83,11)
+select * from t1 where a in (22,83,11) and b=2;
+a	b
+11	2
+11	2
+83	2
+11	2
+83	2
+22	2
+drop table t1;
+set optimizer_switch=@save_optimizer_switch;
 SET SESSION STORAGE_ENGINE=DEFAULT;

mysql-test/main/rowid_filter_innodb.test

@@ -3,6 +3,7 @@
 SET SESSION STORAGE_ENGINE='InnoDB';
 
 --source rowid_filter.test
+--source include/have_sequence.inc
 
 --echo #
 --echo # MDEV-18755: possible RORI-plan and possible plan with range filter
@@ -65,4 +66,33 @@ eval explain extended $q;
 drop table t1, t2;
 
 
+--echo #
+--echo # MDEV-19820: use of rowid filter for innodb table without primary key
+--echo #
+
+create table t1 (a int, b int, key (b), key (a)) engine=innodb;
+insert into t1
+select (rand(1)*1000)/10, (rand(1001)*1000)/50 from seq_1_to_1000;
+analyze table t1;
+
+let $q=
+select count(*) from t1 where a in (22,83,11) and b=2;
+let $q1=
+select * from t1 where a in (22,83,11) and b=2;
+
+set @save_optimizer_switch= @@optimizer_switch;
+
+set optimizer_switch='rowid_filter=off';
+eval $q;
+eval explain extended $q;
+eval $q1;
+
+set optimizer_switch='rowid_filter=on';
+eval $q;
+eval explain extended $q;
+eval $q1;
+
+drop table t1;
+set optimizer_switch=@save_optimizer_switch;
+
 SET SESSION STORAGE_ENGINE=DEFAULT;

storage/innobase/row/row0sel.cc

@@ -3902,11 +3902,25 @@ row_search_idx_cond_check(
 
 	switch (result) {
 	case ICP_MATCH:
-		if (handler_rowid_filter_is_active(prebuilt->pk_filter)
+	        if (handler_rowid_filter_is_active(prebuilt->pk_filter)) {
-		    && !handler_rowid_filter_check(prebuilt->pk_filter)) {
+		        ut_ad(!prebuilt->index->is_primary());
+		        if (prebuilt->clust_index_was_generated) {
+                               ulint len;
+                               dict_index_t* index = prebuilt->index;
+                               const byte* data = rec_get_nth_field(
+                                       rec, offsets, index->n_fields - 1,
+                                       &len);
+                               ut_ad(dict_index_get_nth_col(index,
+                                                            index->n_fields - 1)
+                                     ->prtype == (DATA_ROW_ID | DATA_NOT_NULL));
+                               ut_ad(len == DATA_ROW_ID_LEN);
+                               memcpy(prebuilt->row_id, data, DATA_ROW_ID_LEN);
+                        }
+                        if (!handler_rowid_filter_check(prebuilt->pk_filter)) {
 			        MONITOR_INC(MONITOR_ICP_MATCH);
 			        return(ICP_NO_MATCH);
                         }
+		}
 		/* Convert the remaining fields to MySQL format.
 		If this is a secondary index record, we must defer
 		this until we have fetched the clustered index record. */