Backport 5.5=>5.1 Patch for Bug#13805127:

Stored program cache produces wrong result in same THD.

1 files changed, 22 insertions, 0 deletions

diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 4a0553ad59b..fd9367b99f2 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -305,6 +305,8 @@ void lex_start(THD *thd)
   lex->select_lex.sql_cache= SELECT_LEX::SQL_CACHE_UNSPECIFIED;
   lex->select_lex.init_order();
   lex->select_lex.group_list.empty();
+  if (lex->select_lex.group_list_ptrs)
+    lex->select_lex.group_list_ptrs->clear();
   lex->describe= 0;
   lex->subqueries= FALSE;
   lex->context_analysis_only= 0;
@@ -1632,6 +1634,8 @@ void st_select_lex::init_select()
 {
   st_select_lex_node::init_select();
   group_list.empty();
+  if (group_list_ptrs)
+    group_list_ptrs->clear();
   type= db= 0;
   having= 0;
   table_join_options= 0;
@@ -2901,6 +2905,8 @@ static void fix_prepare_info_in_table_list(THD *thd, TABLE_LIST *tbl)
     The passed WHERE and HAVING are to be saved for the future executions.
     This function saves it, and returns a copy which can be thrashed during
     this execution of the statement. By saving/thrashing here we mean only
+    We also save the chain of ORDER::next in group_list, in case
+    the list is modified by remove_const().
     AND/OR trees.
     The function also calls fix_prepare_info_in_table_list that saves all
     ON expressions.    
@@ -2912,6 +2918,19 @@ void st_select_lex::fix_prepare_information(THD *thd, Item **conds,
   if (!thd->stmt_arena->is_conventional() && first_execution)
   {
     first_execution= 0;
+    if (group_list.first)
+    {
+      if (!group_list_ptrs)
+      {
+        void *mem= thd->stmt_arena->alloc(sizeof(Group_list_ptrs));
+        group_list_ptrs= new (mem) Group_list_ptrs(thd->stmt_arena->mem_root);
+      }
+      group_list_ptrs->reserve(group_list.elements);
+      for (ORDER *order= group_list.first; order; order= order->next)
+      {
+        group_list_ptrs->push_back(order);
+      }
+    }
     if (*conds)
     {
       prep_where= *conds;
@@ -3016,3 +3035,6 @@ bool st_lex::is_partition_management() const
            alter_info.flags == ALTER_REORGANIZE_PARTITION));
 }
 
+#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
+template class Mem_root_array<ORDER*, true>;
+#endif