Merge mysql.com:/home/ram/work/mysql-5.0-maint

into  mysql.com:/home/ram/work/b21976/my50-b21976

1 files changed, 5 insertions, 27 deletions

diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 41f0dd6496b..9c3c5f2053d 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -1050,14 +1050,8 @@ void Item_sum_count::clear()
 
 bool Item_sum_count::add()
 {
-  if (!args[0]->maybe_null)
+  if (!args[0]->maybe_null || !args[0]->is_null())
     count++;
-  else
-  {
-    args[0]->update_null_value();
-    if (!args[0]->null_value)
-      count++;
-  }
   return 0;
 }
 
@@ -1890,14 +1884,8 @@ void Item_sum_count::reset_field()
   char *res=result_field->ptr;
   longlong nr=0;
 
-  if (!args[0]->maybe_null)
+  if (!args[0]->maybe_null || !args[0]->is_null())
     nr=1;
-  else
-  {
-    args[0]->update_null_value();
-    if (!args[0]->null_value)
-      nr=1;
-  }
   int8store(res,nr);
 }
 
@@ -2000,14 +1988,8 @@ void Item_sum_count::update_field()
   char *res=result_field->ptr;
 
   nr=sint8korr(res);
-  if (!args[0]->maybe_null)
+  if (!args[0]->maybe_null || !args[0]->is_null())
     nr++;
-  else
-  {
-    args[0]->update_null_value();
-    if (!args[0]->null_value)
-      nr++;
-  }
   int8store(res,nr);
 }
 
@@ -2431,12 +2413,8 @@ bool Item_sum_count_distinct::setup(THD *thd)
     Item *item=args[i];
     if (list.push_back(item))
       return TRUE;                              // End of memory
-    if (item->const_item())
-    {
-      item->update_null_value();
-      if (item->null_value)
-	always_null=1;
-    }
+    if (item->const_item() && item->is_null())
+      always_null= 1;
   }
   if (always_null)
     return FALSE;