Merge 5.5 into 10.0

mysql-test/r/subselect_sj.result

@@ -3180,5 +3180,12 @@ EXECUTE stmt;
 a
 drop view v3;
 drop table t1,t2,t3;
+#
+# MDEV-18896: IN subquery in WHERE of a table-less query used for INSERT
+#
+create table t1 (a1 varchar(25));
+create table t2 (a2 varchar(25)) ;
+insert into t1 select 'xxx' from dual where 'xxx' in (select a2 from t2);
+drop table t1,t2;
 # End of 5.5 test
 set optimizer_switch=@subselect_sj_tmp;

mysql-test/r/subselect_sj_jcl6.result

@@ -3194,6 +3194,13 @@ EXECUTE stmt;
 a
 drop view v3;
 drop table t1,t2,t3;
+#
+# MDEV-18896: IN subquery in WHERE of a table-less query used for INSERT
+#
+create table t1 (a1 varchar(25));
+create table t2 (a2 varchar(25)) ;
+insert into t1 select 'xxx' from dual where 'xxx' in (select a2 from t2);
+drop table t1,t2;
 # End of 5.5 test
 set optimizer_switch=@subselect_sj_tmp;
 #

mysql-test/t/subselect_sj.test

@@ -2873,6 +2873,16 @@ EXECUTE stmt;
 drop view v3;
 drop table t1,t2,t3;
 
+--echo #
+--echo # MDEV-18896: IN subquery in WHERE of a table-less query used for INSERT
+--echo #
+
+create table t1 (a1 varchar(25));
+create table t2 (a2 varchar(25)) ;
+insert into t1 select 'xxx' from dual where 'xxx' in (select a2 from t2);
+
+drop table t1,t2;
+
 --echo # End of 5.5 test
 
 # The following command must be the last one the file 

sql/opt_subselect.cc

@@ -675,7 +675,7 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
         select_lex->outer_select()->join &&                           // 6
         parent_unit->first_select()->leaf_tables.elements &&          // 7
         !in_subs->has_strategy() &&                                   // 8
-        select_lex->outer_select()->leaf_tables.elements &&           // 9
+        select_lex->outer_select()->table_list.first &&               // 9
         !((join->select_options |                                     // 10
            select_lex->outer_select()->join->select_options)          // 10
           & SELECT_STRAIGHT_JOIN) &&                                  // 10