SQL: incorrect check on specific JOIN query [fixes #145]

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

@@ -406,6 +406,9 @@ create or replace table t1 (x int) with system versioning;
 insert into t1 values (1);
 select * from t1 for system_time all for update;
 ERROR HY000: Wrong parameters for `FOR SYSTEM_TIME query`: write-locking of historic rows
+create or replace table t1 (a int not null auto_increment primary key) with system versioning;
+select * from (t1 as t2 left join t1 as t3 using (a)) natural left join t1;
+a
 drop table t1;
 call verify_vtq;
 No	A	B	C	D

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

@@ -131,6 +131,9 @@ insert into t1 values (1);
 --error ER_VERS_WRONG_PARAMS
 select * from t1 for system_time all for update;
 
+create or replace table t1 (a int not null auto_increment primary key) with system versioning;
+select * from (t1 as t2 left join t1 as t3 using (a)) natural left join t1;
+
 drop table t1;
 
 call verify_vtq;

sql/sql_base.cc

@@ -6420,8 +6420,9 @@ mark_common_columns(THD *thd, TABLE_LIST *table_ref_1, TABLE_LIST *table_ref_2,
       if (!my_strcasecmp(system_charset_info, field_name_1, cur_field_name_2))
       {
         DBUG_PRINT ("info", ("match c1.is_common=%d", nj_col_1->is_common));
-        if (cur_nj_col_2->is_common ||
-            (found && (!using_fields || is_using_column_1)))
+        if ((!it_1.field() || !it_1.field()->vers_sys_field()) &&
+            (cur_nj_col_2->is_common ||
+             (found && (!using_fields || is_using_column_1))))
         {
           my_error(ER_NON_UNIQ_ERROR, MYF(0), field_name_1, thd->where);
           goto err;