5.3 merge

7 files changed, 29 insertions, 16 deletions

diff --git a/sql/item.h b/sql/item.h
index 8074f11da6b..c4fe24bf482 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -3269,13 +3269,16 @@ class Item_direct_view_ref :public Item_direct_ref
   TABLE_LIST *view;
   TABLE *null_ref_table;
 
+#define NO_NULL_TABLE (reinterpret_cast<TABLE *>(0x1))
+
   bool check_null_ref()
   {
     if (null_ref_table == NULL)
     {
-      null_ref_table= view->get_real_join_table();
+      if (!(null_ref_table= view->get_real_join_table()))
+        null_ref_table= NO_NULL_TABLE;
     }
-    if (null_ref_table->null_row)
+    if (null_ref_table != NO_NULL_TABLE && null_ref_table->null_row)
     {
       null_value= 1;
       return TRUE;
diff --git a/sql/item_func.h b/sql/item_func.h
index bbf7643eaa0..f1dbbb09305 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -160,7 +160,8 @@ public:
   inline bool get_arg0_time(MYSQL_TIME *ltime)
   {
     null_value= args[0]->get_time(ltime);
-    DBUG_ASSERT(ltime->time_type != MYSQL_TIMESTAMP_TIME || ltime->day == 0);
+    DBUG_ASSERT(null_value ||
+                ltime->time_type != MYSQL_TIMESTAMP_TIME || ltime->day == 0);
     return null_value;
   }
   bool is_null() { 
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index d54cb54dec6..f689d96b4cf 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -6701,9 +6701,9 @@ find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
           else
           {
             if (thd->mark_used_columns == MARK_COLUMNS_READ)
-              it->walk(&Item::register_field_in_read_map, 1, (uchar *) 0);
+              it->walk(&Item::register_field_in_read_map, 0, (uchar *) 0);
             else
-              it->walk(&Item::register_field_in_write_map, 1, (uchar *) 0);
+              it->walk(&Item::register_field_in_write_map, 0, (uchar *) 0);
           }
         }
         else
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 3c3cb87e9e3..4af06eec658 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -702,7 +702,7 @@ public:
   void print(String *str, enum_query_type query_type);
 
   bool add_fake_select_lex(THD *thd);
-  void init_prepare_fake_select_lex(THD *thd);
+  void init_prepare_fake_select_lex(THD *thd, bool first_execution);
   inline bool is_prepared() { return prepared; }
   bool change_result(select_result_interceptor *result,
                      select_result_interceptor *old_result);
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 0f570a491fc..cd475b28783 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -10813,17 +10813,18 @@ void JOIN::cleanup(bool full)
         tabs_kind= WALK_EXECUTION_TABS;
       if (table_count)
       {
-        for (tab= first_breadth_first_tab(this, tabs_kind); tab; 
+        for (tab= first_breadth_first_tab(this, tabs_kind); tab;
              tab= next_breadth_first_tab(this, tabs_kind, tab))
         {
           tab->cleanup();
         }
       }
       cleaned= true;
+
     }
     else
     {
-      for (tab= first_linear_tab(this, WITH_CONST_TABLES); tab; 
+      for (tab= first_linear_tab(this, WITH_CONST_TABLES); tab;
            tab= next_linear_tab(this, tab, WITH_BUSH_ROOTS))
       {
 	if (tab->table)
diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 22b5e5727e8..72f1df2f4ae 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -193,13 +193,15 @@ void select_union::cleanup()
   SYNOPSIS
     st_select_lex_unit::init_prepare_fake_select_lex()
     thd		- thread handler
+    first_execution - TRUE at the first execution of the union 
 
   RETURN
     options of SELECT
 */
 
 void
-st_select_lex_unit::init_prepare_fake_select_lex(THD *thd_arg) 
+st_select_lex_unit::init_prepare_fake_select_lex(THD *thd_arg,
+                                                  bool first_execution) 
 {
   thd_arg->lex->current_select= fake_select_lex;
   fake_select_lex->table_list.link_in_list(&result_table_list,
@@ -207,7 +209,13 @@ st_select_lex_unit::init_prepare_fake_select_lex(THD *thd_arg)
   fake_select_lex->context.table_list= 
     fake_select_lex->context.first_name_resolution_table= 
     fake_select_lex->get_table_list();
-  if (!fake_select_lex->first_execution)
+  /*
+    The flag fake_select_lex->first_execution indicates whether this is
+    called at the first execution of the statement, while first_execution
+    shows whether this is called at the first execution of the union that
+    may form just a subselect.
+  */    
+  if (!fake_select_lex->first_execution && first_execution)
   {
     for (ORDER *order= global_parameters->order_list.first;
          order;
@@ -481,7 +489,7 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
       {
         /* Validate the global parameters of this union */
 
-	init_prepare_fake_select_lex(thd);
+	init_prepare_fake_select_lex(thd, TRUE);
         /* Should be done only once (the only item_list per statement) */
         DBUG_ASSERT(fake_select_lex->join == 0);
 	if (!(fake_select_lex->join= new JOIN(thd, item_list, thd->variables.option_bits,
@@ -622,6 +630,7 @@ bool st_select_lex_unit::exec()
   SELECT_LEX *select_cursor=first_select();
   ulonglong add_rows=0;
   ha_rows examined_rows= 0;
+  bool first_execution= !executed;
   DBUG_ENTER("st_select_lex_unit::exec");
 
   if (executed && !uncacheable && !describe)
@@ -638,6 +647,7 @@ bool st_select_lex_unit::exec()
     {
       ha_rows records_at_start= 0;
       thd->lex->current_select= sl;
+      fake_select_lex->uncacheable|= sl->uncacheable;
 
       {
         set_limit(sl);
@@ -742,7 +752,7 @@ bool st_select_lex_unit::exec()
     if (!thd->is_fatal_error)				// Check if EOM
     {
       set_limit(global_parameters);
-      init_prepare_fake_select_lex(thd);
+      init_prepare_fake_select_lex(thd, first_execution);
       JOIN *join= fake_select_lex->join;
       if (!join)
       {
diff --git a/sql/table.cc b/sql/table.cc
index 15fbe867c15..c949112e7ee 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -5022,10 +5022,8 @@ TABLE *TABLE_LIST::get_real_join_table()
           */
           for (TABLE_LIST *t= ti++; t; t= ti++)
             tbl= t;
-          /*
-            It is impossible that the list is empty
-            so tbl can't be NULL after above loop.
-          */
+          if (!tbl)
+            return NULL; // view/derived with no tables
           if (!tbl->nested_join)
             break;
           /* go deeper if we've found nested join */