Fixed bug #27937: crash for the the second execution of a prepared

statement from a UNION query with ORDER BY an expression containing
RAND().
The crash happened because the global order by list in the union query
was not re-initialized for execution.
(Local order by lists were re-initialized though).



mysql-test/r/ps.result:
  Added a test case for bug #27937.
mysql-test/t/ps.test:
  Added a test case for bug #27937.
sql/sql_union.cc:
  Fixed bug #27937: crash for the the second execution of a prepared
  statement from a UNION query with ORDER BY an expression containing
  RAND().
  The crash happened because the global order by list in the union query
  was not re-initialized for execution.
  (Local order by lists were re-initialized though).
  Added re-initialization of the global order by list in the function
  st_select_lex_unit::init_prepare_fake_select_lex.

1 files changed, 5 insertions, 0 deletions

diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index f3f814831f5..615d060a5a8 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -135,6 +135,11 @@ st_select_lex_unit::init_prepare_fake_select_lex(THD *thd)
   fake_select_lex->table_list.link_in_list((byte *)&result_table_list,
 					   (byte **)
 					   &result_table_list.next);
+  for (ORDER *order= (ORDER *) global_parameters->order_list.first;
+       order;
+       order= order->next)
+    order->item= &order->item_ptr;
+
   return options_tmp;
 }