MDEV-31237 Assertion `!(tab->select && tab->select->quick)' failed in…

… make_join_readinfo

The problem was a wrong assert. I changed it to match the code in
best_access_path().

The given test case was a bit tricky for the optimizer, which first
decided on using a index scan (because of force index), but then
test_if_skip_sort_order() decided to use range anyway to handle
distinct.

mysql-test/main/range.result

@@ -3824,5 +3824,20 @@ id	MIN(id)
 8	8
 DROP TABLE t1;
 #
+# MDEV-31237 Assertion `!(tab->select && tab->select->quick)' failed
+# in make_join_readinfo
+#
+CREATE TABLE lineitem (l_orderkey int, l_linenumber int, l_receiptDATE date DEFAULT NULL, PRIMARY KEY (l_orderkey,l_linenumber), KEY i_l_receiptdate (l_receiptDATE), KEY i_l_orderkey (l_orderkey)) ENGINE=InnoDB;
+INSERT INTO lineitem VALUES (291,1,'1994-06-23'),(291,2,'1994-06-19'),
+(291,3,'1994-03-24'),(292,1,'1992-03-18'),(292,2,'1992-04-20');
+EXPLAIN SELECT DISTINCT l_orderkey FROM lineitem FORCE KEY (i_l_orderkey, i_l_receiptdate) WHERE l_orderkey > 1 ORDER BY l_receiptdate;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	lineitem	range	i_l_orderkey	i_l_orderkey	4	NULL	5	Using where; Using temporary; Using filesort
+SELECT DISTINCT l_orderkey FROM lineitem FORCE KEY (i_l_orderkey, i_l_receiptdate) WHERE l_orderkey > 1 ORDER BY l_receiptdate;
+l_orderkey
+292
+291
+DROP TABLE lineitem;
+#
 # End of 11.0 tests
 #

mysql-test/main/range.test

@@ -2602,6 +2602,18 @@ WHERE (b > 'TX' OR b BETWEEN 'NE' AND 'SC') AND id IN (1,7,8) AND a = 5
 GROUP BY id;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-31237 Assertion `!(tab->select && tab->select->quick)' failed
+--echo # in make_join_readinfo
+--echo #
+
+CREATE TABLE lineitem (l_orderkey int, l_linenumber int, l_receiptDATE date DEFAULT NULL, PRIMARY KEY (l_orderkey,l_linenumber), KEY i_l_receiptdate (l_receiptDATE), KEY i_l_orderkey (l_orderkey)) ENGINE=InnoDB;
+INSERT INTO lineitem VALUES (291,1,'1994-06-23'),(291,2,'1994-06-19'),
+       (291,3,'1994-03-24'),(292,1,'1992-03-18'),(292,2,'1992-04-20');
+EXPLAIN SELECT DISTINCT l_orderkey FROM lineitem FORCE KEY (i_l_orderkey, i_l_receiptdate) WHERE l_orderkey > 1 ORDER BY l_receiptdate;
+SELECT DISTINCT l_orderkey FROM lineitem FORCE KEY (i_l_orderkey, i_l_receiptdate) WHERE l_orderkey > 1 ORDER BY l_receiptdate;
+DROP TABLE lineitem;
+
 --echo #
 --echo # End of 11.0 tests
 --echo #

mysql-test/main/range_mrr_icp.result

@@ -3821,6 +3821,21 @@ id	MIN(id)
 8	8
 DROP TABLE t1;
 #
+# MDEV-31237 Assertion `!(tab->select && tab->select->quick)' failed
+# in make_join_readinfo
+#
+CREATE TABLE lineitem (l_orderkey int, l_linenumber int, l_receiptDATE date DEFAULT NULL, PRIMARY KEY (l_orderkey,l_linenumber), KEY i_l_receiptdate (l_receiptDATE), KEY i_l_orderkey (l_orderkey)) ENGINE=InnoDB;
+INSERT INTO lineitem VALUES (291,1,'1994-06-23'),(291,2,'1994-06-19'),
+(291,3,'1994-03-24'),(292,1,'1992-03-18'),(292,2,'1992-04-20');
+EXPLAIN SELECT DISTINCT l_orderkey FROM lineitem FORCE KEY (i_l_orderkey, i_l_receiptdate) WHERE l_orderkey > 1 ORDER BY l_receiptdate;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	lineitem	range	i_l_orderkey	i_l_orderkey	4	NULL	5	Using where; Using temporary; Using filesort
+SELECT DISTINCT l_orderkey FROM lineitem FORCE KEY (i_l_orderkey, i_l_receiptdate) WHERE l_orderkey > 1 ORDER BY l_receiptdate;
+l_orderkey
+292
+291
+DROP TABLE lineitem;
+#
 # End of 11.0 tests
 #
 set optimizer_switch=@mrr_icp_extra_tmp;

sql/sql_select.cc

@@ -15373,7 +15373,16 @@ make_join_readinfo(JOIN *join, ulonglong options, uint no_jbuf_after)
         push_index_cond(tab, tab->ref.key);
       break;
     case JT_NEXT:                               // Index scan
-      DBUG_ASSERT(!(tab->select && tab->select->quick));
+      DBUG_ASSERT(!tab->quick);
+      if (tab->select)
+      {
+        /*
+          select->quick may be set if there was a possible range and
+          it had a higher cost than a table scan.
+        */
+	delete tab->select->quick;
+	tab->select->quick=0;
+      }
       if (tab->use_quick == 2)
       {
         join->thd->set_status_no_good_index_used();