SQL: fix subquery not a derived table [#365 bug 9]

Tests affected (forced mode):

main.ps \
main.user_var \
main.myisam_explain_non_select_all \
main.opt_tvc \
main.subselect \
main.subselect_no_exists_to_in \
main.derived \
main.derived_opt \
main.update

mysql-test/suite/versioning/r/select.result

@@ -298,6 +298,10 @@ create or replace table t2 (b int) with system versioning;
 select * from t1
 where exists (select 1 from t2 where t2.b = t1.a and t2.b = t1.a);
 a
+### Issue #365, bug 9 (not a derived subquery)
+create or replace table t1 (x int) with system versioning;
+select t1.x in (select x from t1) a from t1, (select x from t1) b;
+a
 drop view v1;
 drop table t1, t2;
 call innodb_verify_vtq(28);

mysql-test/suite/versioning/t/select.test

@@ -195,6 +195,10 @@ create or replace table t2 (b int) with system versioning;
 select * from t1
 where exists (select 1 from t2 where t2.b = t1.a and t2.b = t1.a);
 
+--echo ### Issue #365, bug 9 (not a derived subquery)
+create or replace table t1 (x int) with system versioning;
+select t1.x in (select x from t1) a from t1, (select x from t1) b;
+
 drop view v1;
 drop table t1, t2;
 

sql/sql_select.cc

@@ -791,14 +791,14 @@ int vers_setup_select(THD *thd, TABLE_LIST *tables, COND **where_expr,
       if (!vers_conditions && outer_slex && slex->vers_import_outer)
       {
         TABLE_LIST* derived= slex->master_unit()->derived;
-        while (outer_slex && (!derived->vers_conditions || derived->vers_conditions.from_inner))
+        // inner SELECT may not be a derived table (derived == NULL)
+        while (derived && outer_slex && (!derived->vers_conditions || derived->vers_conditions.from_inner))
         {
           derived= outer_slex->master_unit()->derived;
           outer_slex= outer_slex->next_select_in_list();
         }
-        if (outer_slex)
+        if (derived && outer_slex && !derived->vers_conditions.from_inner)
         {
-          DBUG_ASSERT(derived);
           DBUG_ASSERT(derived->vers_conditions);
           vers_conditions= derived->vers_conditions;
         }