Fix for bug#15153 "CONVERT_TZ() is not allowed in all places in VIEWs".

Error was emitted when one tried to select information from view which used
merge algorithm and which also had CONVERT_TZ() function in its select list.

This bug was caused by wrong assumption that global table list for view
which is handled using merge algorithm begins from tables belonging to
the main select of this view. Nowadays the above assumption is not true only
when one uses convert_tz() function in view's select list, but in future
other cases may be added (for example we may support merging of views
with subqueries in select list one day). Relying on this false assumption
led to the usage of wrong table list for field lookups and therefor errors. 

With this fix we explicitly use pointer to the beginning of main select's
table list.

mysql-test/r/timezone_grant.result

+drop tables if exists t1, t2;
+drop view if exists v1;
 delete from mysql.user where user like 'mysqltest\_%';
 delete from mysql.db where user like 'mysqltest\_%';
 delete from mysql.tables_priv where user like 'mysqltest\_%';
@@ -59,3 +61,18 @@ delete from mysql.db where user like 'mysqltest\_%';
 delete from mysql.tables_priv where user like 'mysqltest\_%';
 flush privileges;
 drop table t1, t2;
+create table t1 (a int, b datetime);
+insert into t1 values (1, 20010101000000), (2, 20020101000000);
+grant all privileges on test.* to mysqltest_1@localhost;
+create view v1 as select a, convert_tz(b, 'UTC', 'Europe/Moscow') as lb from t1;
+select * from v1;
+a	lb
+1	2001-01-01 03:00:00
+2	2002-01-01 03:00:00
+select * from v1, mysql.time_zone;
+ERROR 42000: SELECT command denied to user 'mysqltest_1'@'localhost' for table 'time_zone'
+drop view v1;
+create view v1 as select a, convert_tz(b, 'UTC', 'Europe/Moscow') as lb from t1, mysql.time_zone;
+ERROR 42000: ANY command denied to user 'mysqltest_1'@'localhost' for table 'time_zone'
+drop table t1;
+drop user mysqltest_1@localhost;

mysql-test/r/view.result

@@ -2623,3 +2623,29 @@ select * from v1;
 ERROR HY000: Recursive stored functions and triggers are not allowed.
 drop function f1;
 drop view t1, v1;
+create table t1 (dt datetime);
+insert into t1 values (20040101000000), (20050101000000), (20060101000000);
+create view v1 as select convert_tz(dt, 'UTC', 'Europe/Moscow') as ldt from t1;
+select * from v1;
+ldt
+2004-01-01 03:00:00
+2005-01-01 03:00:00
+2006-01-01 03:00:00
+drop view v1;
+create view v1 as select * from t1 where convert_tz(dt, 'UTC', 'Europe/Moscow') >= 20050101000000;
+select * from v1;
+dt
+2005-01-01 00:00:00
+2006-01-01 00:00:00
+create view v2 as select * from v1 where dt < 20060101000000;
+select * from v2;
+dt
+2005-01-01 00:00:00
+drop view v2;
+create view v2 as select convert_tz(dt, 'UTC', 'Europe/Moscow') as ldt from v1;
+select * from v2;
+ldt
+2005-01-01 03:00:00
+2006-01-01 03:00:00
+drop view v1, v2;
+drop table t1;

mysql-test/t/timezone_grant.test

 # Embedded server testing does not support grants
 -- source include/not_embedded.inc
 
+--disable_warnings
+drop tables if exists t1, t2;
+drop view if exists v1;
+--enable_warnings
+
 #
 # Test for bug #6116 "SET time_zone := ... requires access to mysql.time_zone
 # tables". We should allow implicit access to time zone description tables
@@ -82,3 +87,29 @@ flush privileges;
 drop table t1, t2;
 
 # End of 4.1 tests
+
+#
+# Additional test for bug #15153: CONVERT_TZ() is not allowed in all
+# places in views.
+#
+# Let us check that usage of CONVERT_TZ() function in view does not 
+# require additional privileges.
+
+# Let us rely on that previous tests done proper cleanups
+create table t1 (a int, b datetime);
+insert into t1 values (1, 20010101000000), (2, 20020101000000);
+grant all privileges on test.* to mysqltest_1@localhost;
+connect (tzuser3, localhost, mysqltest_1,,);
+create view v1 as select a, convert_tz(b, 'UTC', 'Europe/Moscow') as lb from t1;
+select * from v1;
+# Of course we should not be able select from mysql.time_zone tables
+--error ER_TABLEACCESS_DENIED_ERROR
+select * from v1, mysql.time_zone;
+drop view v1;
+--error ER_TABLEACCESS_DENIED_ERROR
+create view v1 as select a, convert_tz(b, 'UTC', 'Europe/Moscow') as lb from t1, mysql.time_zone;
+connection default;
+drop table t1;
+drop user mysqltest_1@localhost;
+
+# End of 5.0 tests

mysql-test/t/view.test

@@ -2485,3 +2485,30 @@ rename table v2 to t1;
 select * from v1;
 drop function f1;
 drop view t1, v1;
+
+#
+# Bug #15153: CONVERT_TZ() is not allowed in all places in VIEWs
+#
+# Error was reported when one tried to use CONVERT_TZ() function
+# select list of view which was processed using MERGE algorithm.
+# (Also see additional test in timezone_grant.test)
+create table t1 (dt datetime);
+insert into t1 values (20040101000000), (20050101000000), (20060101000000);
+# Let us test that convert_tz() can be used in view's select list
+create view v1 as select convert_tz(dt, 'UTC', 'Europe/Moscow') as ldt from t1;
+select * from v1;
+drop view v1;
+# And in its where part 
+create view v1 as select * from t1 where convert_tz(dt, 'UTC', 'Europe/Moscow') >= 20050101000000;
+select * from v1;
+# Other interesting case - a view which uses convert_tz() function
+# through other view.
+create view v2 as select * from v1 where dt < 20060101000000;
+select * from v2;
+drop view v2;
+# And even more interesting case when view uses convert_tz() both
+# directly and indirectly
+create view v2 as select convert_tz(dt, 'UTC', 'Europe/Moscow') as ldt from v1;
+select * from v2;
+drop view v1, v2;
+drop table t1;

sql/sql_view.cc

@@ -1057,15 +1057,23 @@ bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table)
         !old_lex->can_not_use_merged())
     {
       List_iterator_fast<TABLE_LIST> ti(view_select->top_join_list);
+      /*
+        Currently 'view_main_select_tables' differs from 'view_tables'
+        only then view has CONVERT_TZ() function in its select list.
+        This may change in future, for example if we enable merging
+        of views with subqueries in select list.
+      */
+      TABLE_LIST *view_main_select_tables=
+                    (TABLE_LIST*)lex->select_lex.table_list.first;
       /* lex should contain at least one table */
-      DBUG_ASSERT(view_tables != 0);
+      DBUG_ASSERT(view_main_select_tables != 0);
 
       table->effective_algorithm= VIEW_ALGORITHM_MERGE;
       DBUG_PRINT("info", ("algorithm: MERGE"));
       table->updatable= (table->updatable_view != 0);
       table->effective_with_check=
         old_lex->get_effective_with_check(table);
-      table->merge_underlying_list= view_tables;
+      table->merge_underlying_list= view_main_select_tables;
       /*
         Let us set proper lock type for tables of the view's main select
         since we may want to perform update or insert on view. This won't
@@ -1081,7 +1089,7 @@ bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table)
       }
 
       /* prepare view context */
-      lex->select_lex.context.resolve_in_table_list_only(view_tables);
+      lex->select_lex.context.resolve_in_table_list_only(view_main_select_tables);
       lex->select_lex.context.outer_context= 0;
       lex->select_lex.context.select_lex= table->select_lex;
       lex->select_lex.select_n_having_items+=
@@ -1097,7 +1105,7 @@ bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table)
         tbl->select_lex= table->select_lex;
 
       {
-        if (view_tables->next_local)
+        if (view_main_select_tables->next_local)
         {
           table->multitable_view= TRUE;
           if (table->belong_to_view)