Merge bk-internal.mysql.com:/home/bk/mysql-4.1

into mysql.com:/home/dlenev/src/mysql-4.1-tzbug

mysql-test/r/timezone2.result

@@ -303,3 +303,11 @@ delete from mysql.db where user like 'mysqltest\_%';
 delete from mysql.tables_priv where user like 'mysqltest\_%';
 flush privileges;
 drop table t1, t2;
+select convert_tz('2005-01-14 17:00:00', 'UTC', custTimeZone) from (select 'UTC' as custTimeZone) as tmp;
+convert_tz('2005-01-14 17:00:00', 'UTC', custTimeZone)
+2005-01-14 17:00:00
+create table t1 select convert_tz(NULL, NULL, NULL);
+select * from t1;
+convert_tz(NULL, NULL, NULL)
+NULL
+drop table t1;

mysql-test/t/timezone2.test

@@ -266,3 +266,20 @@ delete from mysql.db where user like 'mysqltest\_%';
 delete from mysql.tables_priv where user like 'mysqltest\_%';
 flush privileges;
 drop table t1, t2;
+
+#
+# Test for bug #7705 "CONVERT_TZ() crashes with subquery/WHERE on index 
+# column". Queries in which one of time zone arguments of CONVERT_TZ() is
+# determined as constant only at val() stage (not at fix_fields() stage),
+# should not crash server.
+#
+select convert_tz('2005-01-14 17:00:00', 'UTC', custTimeZone) from (select 'UTC' as custTimeZone) as tmp;
+
+#
+# Test for bug #7899 "CREATE TABLE .. SELECT .. and CONVERT_TZ() function
+# does not work well together". The following statement should return only
+# one NULL row and not result of full join.
+#
+create table t1 select convert_tz(NULL, NULL, NULL);
+select * from t1;
+drop table t1;

sql/item_timefunc.cc

@@ -1656,6 +1656,7 @@ void Item_func_convert_tz::fix_length_and_dec()
   collation.set(&my_charset_bin);
   decimals= 0;
   max_length= MAX_DATETIME_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
+  maybe_null= 1;
 }
 
 
@@ -1668,12 +1669,6 @@ Item_func_convert_tz::fix_fields(THD *thd_arg, TABLE_LIST *tables_arg, Item **re
 
   tz_tables= thd_arg->lex->time_zone_tables_used;
 
-  if (args[1]->const_item())
-    from_tz= my_tz_find(args[1]->val_str(&str), tz_tables);
-
-  if (args[2]->const_item())
-    to_tz= my_tz_find(args[2]->val_str(&str), tz_tables);
-
   return 0;
 }
 
@@ -1714,11 +1709,17 @@ bool Item_func_convert_tz::get_date(TIME *ltime,
   bool not_used;
   String str;
 
-  if (!args[1]->const_item())
+  if (!from_tz_cached)
+  {
     from_tz= my_tz_find(args[1]->val_str(&str), tz_tables);
+    from_tz_cached= args[1]->const_item();
+  }
 
-  if (!args[2]->const_item())
+  if (!to_tz_cached)
+  {
     to_tz= my_tz_find(args[2]->val_str(&str), tz_tables);
+    to_tz_cached= args[2]->const_item();
+  }
 
   if (from_tz==0 || to_tz==0 || get_arg0_date(ltime, 0))
   {
@@ -1741,6 +1742,13 @@ bool Item_func_convert_tz::get_date(TIME *ltime,
 }
 
 
+void Item_func_convert_tz::cleanup()
+{
+  from_tz_cached= to_tz_cached= 0;
+  Item_date_func::cleanup();
+}
+
+
 void Item_date_add_interval::fix_length_and_dec()
 {
   enum_field_types arg0_field_type;

sql/item_timefunc.h

@@ -545,12 +545,15 @@ class Item_func_convert_tz :public Item_date_func
   TABLE_LIST *tz_tables;
   /*
     If time zone parameters are constants we are caching objects that
-    represent them.
+    represent them (we use separate from_tz_cached/to_tz_cached members
+    to indicate this fact, since NULL is legal value for from_tz/to_tz
+    members.
   */
+  bool from_tz_cached, to_tz_cached;
   Time_zone *from_tz, *to_tz;
  public:
   Item_func_convert_tz(Item *a, Item *b, Item *c):
-    Item_date_func(a, b, c) {}
+    Item_date_func(a, b, c), from_tz_cached(0), to_tz_cached(0) {}
   longlong val_int();
   double val() { return (double) val_int(); }
   String *val_str(String *str);
@@ -558,6 +561,7 @@ class Item_func_convert_tz :public Item_date_func
   bool fix_fields(THD *, struct st_table_list *, Item **);
   void fix_length_and_dec();
   bool get_date(TIME *res, uint fuzzy_date);
+  void cleanup();
 };
 
 

sql/set_var.cc

@@ -2438,8 +2438,15 @@ bool sys_var_thd_time_zone::check(THD *thd, set_var *var)
 
 bool sys_var_thd_time_zone::update(THD *thd, set_var *var)
 {
-  /* We are using Time_zone object found during check() phase */ 
-  *get_tz_ptr(thd,var->type)= var->save_result.time_zone;
+  /* We are using Time_zone object found during check() phase. */
+  if (var->type == OPT_GLOBAL)
+  {
+    pthread_mutex_lock(&LOCK_global_system_variables);
+    global_system_variables.time_zone= var->save_result.time_zone;
+    pthread_mutex_unlock(&LOCK_global_system_variables);
+  }
+  else
+    thd->variables.time_zone= var->save_result.time_zone;
   return 0;
 }
 
@@ -2451,27 +2458,25 @@ byte *sys_var_thd_time_zone::value_ptr(THD *thd, enum_var_type type,
     We can use ptr() instead of c_ptr() here because String contaning
     time zone name is guaranteed to be zero ended.
   */
-  return (byte *)((*get_tz_ptr(thd,type))->get_name()->ptr());
-}
-
-
-Time_zone** sys_var_thd_time_zone::get_tz_ptr(THD *thd, 
-                                              enum_var_type type)
-{
   if (type == OPT_GLOBAL)
-    return &global_system_variables.time_zone;
+    return (byte *)(global_system_variables.time_zone->get_name()->ptr());
   else
-    return &thd->variables.time_zone;
+    return (byte *)(thd->variables.time_zone->get_name()->ptr());
 }
 
 
 void sys_var_thd_time_zone::set_default(THD *thd, enum_var_type type)
 {
+ pthread_mutex_lock(&LOCK_global_system_variables);
  if (type == OPT_GLOBAL)
  {
    if (default_tz_name)
    {
      String str(default_tz_name, &my_charset_latin1);
+     /*
+       We are guaranteed to find this time zone since its existence
+       is checked during start-up.
+     */
      global_system_variables.time_zone=
        my_tz_find(&str, thd->lex->time_zone_tables_used);
    }
@@ -2480,6 +2485,7 @@ void sys_var_thd_time_zone::set_default(THD *thd, enum_var_type type)
  }
  else
    thd->variables.time_zone= global_system_variables.time_zone;
+ pthread_mutex_unlock(&LOCK_global_system_variables);
 }
 
 /*

sql/set_var.h

@@ -736,7 +736,6 @@ class sys_var_thd_time_zone :public sys_var_thd
   bool update(THD *thd, set_var *var);
   byte *value_ptr(THD *thd, enum_var_type type, LEX_STRING *base);
   virtual void set_default(THD *thd, enum_var_type type);
-  Time_zone **get_tz_ptr(THD *thd, enum_var_type type);
 };
 
 /****************************************************************************

sql/sql_lex.cc

@@ -1718,8 +1718,8 @@ st_lex::st_lex()
     global_first	Save first global table here
     local_first		Save first local table here
 
-  NORES
-   global_first & local_first are used to save result for link_first_table_back
+  NOTES
+    This function assumes that outer select list is non-empty.
 
   RETURN
     global list without first table
@@ -1729,25 +1729,25 @@ TABLE_LIST *st_lex::unlink_first_table(TABLE_LIST *tables,
 				       TABLE_LIST **global_first,
 				       TABLE_LIST **local_first)
 {
-  *global_first= tables;
-  *local_first= (TABLE_LIST*)select_lex.table_list.first;
+  DBUG_ASSERT(select_lex.table_list.first != 0);
   /*
-    Exclude from global table list
+    Save pointers to first elements of global table list and list
+    of tables used in outer select. It does not harm if these lists
+    are the same.
   */
+  *global_first= tables;
+  *local_first= (TABLE_LIST*)select_lex.table_list.first;
+
+  /* Exclude first elements from these lists */
+  select_lex.table_list.first= (byte*) (*local_first)->next;
   tables= tables->next;
-  /*
-    and from local list if it is not the same
-  */
-  select_lex.table_list.first= ((&select_lex != all_selects_list) ?
-				(byte*) (*local_first)->next :
-				(byte*) tables);
   (*global_first)->next= 0;
   return tables;
 }
 
 
 /*
-  Link table back that was unlinked with unlink_first_table()
+  Link table which was unlinked with unlink_first_table() back.
 
   SYNOPSIS
     link_first_table_back()
@@ -1763,16 +1763,7 @@ TABLE_LIST *st_lex::link_first_table_back(TABLE_LIST *tables,
 					  TABLE_LIST *local_first)
 {
   global_first->next= tables;
-  if (&select_lex != all_selects_list)
-  {
-    /*
-      we do not touch local table 'next' field => we need just
-      put the table in the list
-    */
   select_lex.table_list.first= (byte*) local_first;
-  }
-  else
-    select_lex.table_list.first= (byte*) global_first;
   return global_first;
 }
 

sql/tztime.cc

@@ -1773,7 +1773,13 @@ tz_load_from_open_tables(const String *tz_name, TABLE_LIST *tz_tables)
   if (table->file->index_read(table->record[0], (byte*)table->field[0]->ptr,
                               0, HA_READ_KEY_EXACT))
   {
-    sql_print_error("Can't find description of time zone.");
+#ifdef EXTRA_DEBUG    
+    /*
+      Most probably user has mistyped time zone name, so no need to bark here
+      unless we need it for debugging.
+    */
+    sql_print_error("Can't find description of time zone '%s'", tz_name_buff);
+#endif
     goto end;
   }
 
@@ -1794,7 +1800,7 @@ tz_load_from_open_tables(const String *tz_name, TABLE_LIST *tz_tables)
   if (table->file->index_read(table->record[0], (byte*)table->field[0]->ptr,
                               0, HA_READ_KEY_EXACT))
   {
-    sql_print_error("Can't find description of time zone.");
+    sql_print_error("Can't find description of time zone '%u'", tzid);
     goto end;
   }