Merge 10.4 into 10.5

1 files changed, 17 insertions, 6 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 0774dc15ef8..2347162ff84 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1036,10 +1036,16 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables)
 
     if (vers_conditions.is_set())
     {
+      if (vers_conditions.was_set() &&
+          table->lock_type > TL_READ_NO_INSERT &&
+          !vers_conditions.delete_history)
+      {
+        my_error(ER_TABLE_NOT_LOCKED_FOR_WRITE, MYF(0), table->alias.str);
+        DBUG_RETURN(-1);
+      }
+
       if (vers_conditions.type == SYSTEM_TIME_ALL)
         continue;
-
-      lock_type= TL_READ; // ignore TL_WRITE, history is immutable anyway
     }
 
     bool timestamps_only= table->table->versioned(VERS_TIMESTAMP);
@@ -2768,11 +2774,16 @@ int JOIN::optimize_stage2()
   }
 
   need_tmp= test_if_need_tmp_table();
-  //TODO this could probably go in test_if_need_tmp_table.
-  if (this->select_lex->window_specs.elements > 0) {
-    need_tmp= TRUE;
+
+  /*
+    If window functions are present then we can't have simple_order set to
+    TRUE as the window function needs a temp table for computation.
+    ORDER BY is computed after the window function computation is done, so
+    the sort will be done on the temp table.
+  */
+  if (select_lex->have_window_funcs())
     simple_order= FALSE;
-  }
+
 
   /*
     If the hint FORCE INDEX FOR ORDER BY/GROUP BY is used for the table