fixed ORDER BY ?

new tests to ensure that prepared statement *really* work
(and that MySQL not picks up some number from arbitrary location
that happens to match the parameter's value)

mysql-test/include/ps_query.inc

@@ -246,6 +246,11 @@ select a,b from t1 order by 2 ;
 prepare stmt1 from ' select a,b from t1
 order by ? ';
 execute stmt1 using @arg00;
+set @arg00=1 ;
+execute stmt1 using @arg00;
+set @arg00=0 ;
+--error 1054
+execute stmt1 using @arg00;
 
 ##### parameter used in limit clause
 set @arg00=1;

mysql-test/r/ps_2myisam.result

@@ -334,6 +334,16 @@ a	b
 1	one
 3	three
 2	two
+set @arg00=1 ;
+execute stmt1 using @arg00;
+a	b
+1	one
+2	two
+3	three
+4	four
+set @arg00=0 ;
+execute stmt1 using @arg00;
+ERROR 42S22: Unknown column '?' in 'order clause'
 set @arg00=1;
 prepare stmt1 from ' select a,b from t1
 limit 1 ';

mysql-test/r/ps_3innodb.result

@@ -334,6 +334,16 @@ a	b
 1	one
 3	three
 2	two
+set @arg00=1 ;
+execute stmt1 using @arg00;
+a	b
+1	one
+2	two
+3	three
+4	four
+set @arg00=0 ;
+execute stmt1 using @arg00;
+ERROR 42S22: Unknown column '?' in 'order clause'
 set @arg00=1;
 prepare stmt1 from ' select a,b from t1
 limit 1 ';

mysql-test/r/ps_4heap.result

@@ -335,6 +335,16 @@ a	b
 1	one
 3	three
 2	two
+set @arg00=1 ;
+execute stmt1 using @arg00;
+a	b
+1	one
+2	two
+3	three
+4	four
+set @arg00=0 ;
+execute stmt1 using @arg00;
+ERROR 42S22: Unknown column '?' in 'order clause'
 set @arg00=1;
 prepare stmt1 from ' select a,b from t1
 limit 1 ';

mysql-test/r/ps_5merge.result

@@ -377,6 +377,16 @@ a	b
 1	one
 3	three
 2	two
+set @arg00=1 ;
+execute stmt1 using @arg00;
+a	b
+1	one
+2	two
+3	three
+4	four
+set @arg00=0 ;
+execute stmt1 using @arg00;
+ERROR 42S22: Unknown column '?' in 'order clause'
 set @arg00=1;
 prepare stmt1 from ' select a,b from t1
 limit 1 ';
@@ -1560,6 +1570,16 @@ a	b
 1	one
 3	three
 2	two
+set @arg00=1 ;
+execute stmt1 using @arg00;
+a	b
+1	one
+2	two
+3	three
+4	four
+set @arg00=0 ;
+execute stmt1 using @arg00;
+ERROR 42S22: Unknown column '?' in 'order clause'
 set @arg00=1;
 prepare stmt1 from ' select a,b from t1
 limit 1 ';

mysql-test/r/ps_6bdb.result

@@ -334,6 +334,16 @@ a	b
 1	one
 3	three
 2	two
+set @arg00=1 ;
+execute stmt1 using @arg00;
+a	b
+1	one
+2	two
+3	three
+4	four
+set @arg00=0 ;
+execute stmt1 using @arg00;
+ERROR 42S22: Unknown column '?' in 'order clause'
 set @arg00=1;
 prepare stmt1 from ' select a,b from t1
 limit 1 ';

sql/sql_select.cc

@@ -8000,7 +8000,7 @@ find_order_in_list(THD *thd, Item **ref_pointer_array,
   Item *itemptr=*order->item;
   if (itemptr->type() == Item::INT_ITEM)
   {						/* Order by position */
-    uint count= (uint) ((Item_int*)itemptr)->value;
+    uint count= itemptr->val_int();
     if (!count || count > fields.elements)
     {
       my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),