Fixed bug mdev-10705.

The fix for bug mdev-5104 did not take into account that
for any call of setup_order the size of ref_array must
be big enough. This patch fixes this problem.

mysql-test/r/order_by.result

@@ -2050,4 +2050,15 @@ t2 A, t2 B
 where A.b = B.b
 order by A.col2, B.col2 limit 10, 1000000;
 drop table t1,t2,t3;
+#
+# mdev-10705 : long order by list that can be skipped
+#
+SELECT 1 
+UNION 
+( SELECT 2 
+ORDER BY NULL, @a0 := 3, @a1 := 3, @a2 := 3, @a3 := 3, @a4 := 3,
+@a5 := 3, @a6 := 3, @a7 := 3, @a8 := 3, @a9 := 3, @a10 := 3 );
+1
+1
+2
 End of 5.5 tests

mysql-test/t/order_by.test

@@ -1746,6 +1746,16 @@ order by A.col2, B.col2 limit 10, 1000000;
 
 drop table t1,t2,t3;
 
+--echo #
+--echo # mdev-10705 : long order by list that can be skipped
+--echo #
+
+SELECT 1 
+UNION 
+( SELECT 2 
+    ORDER BY NULL, @a0 := 3, @a1 := 3, @a2 := 3, @a3 := 3, @a4 := 3,
+             @a5 := 3, @a6 := 3, @a7 := 3, @a8 := 3, @a9 := 3, @a10 := 3 );
+
 --echo End of 5.5 tests
 
 

sql/sql_select.cc

@@ -714,10 +714,15 @@ JOIN::prepare(Item ***rref_pointer_array,
     if (mixed_implicit_grouping && tbl->table)
       tbl->table->maybe_null= 1;
   }
+ 
+  uint real_og_num= og_num;
+  if (skip_order_by && 
+      select_lex != select_lex->master_unit()->global_parameters)
+    real_og_num+= select_lex->order_list.elements;
 
   if ((wild_num && setup_wild(thd, tables_list, fields_list, &all_fields,
                               wild_num)) ||
-      select_lex->setup_ref_array(thd, og_num) ||
+      select_lex->setup_ref_array(thd, real_og_num) ||
       setup_fields(thd, (*rref_pointer_array), fields_list, MARK_COLUMNS_READ,
 		   &all_fields, 1) ||
       setup_without_group(thd, (*rref_pointer_array), tables_list,