1 files changed, 18 insertions, 1 deletions
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 37ec33c8358..4a7a44b3399 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -4982,6 +4982,19 @@ Item *Item_cond::build_clone(THD *thd)
 }
 
 
+bool Item_cond::excl_dep_on_grouping_fields(st_select_lex *sel)
+{
+  List_iterator_fast<Item> li(list);
+  Item *item;
+  while ((item= li++))
+  {
+    if (!item->excl_dep_on_grouping_fields(sel))
+      return false;
+  }
+  return true;
+}
+
+
 void Item_cond_and::mark_as_condition_AND_part(TABLE_LIST *embedding)
 {
   List_iterator<Item> li(list);
@@ -5118,7 +5131,11 @@ longlong Item_func_isnull::val_int()
 
 void Item_func_isnull::print(String *str, enum_query_type query_type)
 {
-  args[0]->print_parenthesised(str, query_type, precedence());
+  if (const_item() && !args[0]->maybe_null &&
+      !(query_type & (QT_NO_DATA_EXPANSION | QT_VIEW_INTERNAL)))
+    str->append("/*always not null*/ 1");
+  else
+    args[0]->print_parenthesised(str, query_type, precedence());
   str->append(STRING_WITH_LEN(" is null"));
 }