Fix Item tree changes/rollback debug print

sql/sql_class.cc

@@ -2234,6 +2234,9 @@ void THD::check_and_register_item_tree_change(Item **place, Item **new_value,
                                               MEM_ROOT *runtime_memroot)
 {
   Item_change_record *change;
+  DBUG_ENTER("THD::check_and_register_item_tree_change");
+  DBUG_PRINT("enter", ("Register: %p (%p) <- %p (%p)",
+                       *place, place, *new_value, new_value));
   I_List_iterator<Item_change_record> it(change_list);
   while ((change= it++))
   {
@@ -2243,6 +2246,7 @@ void THD::check_and_register_item_tree_change(Item **place, Item **new_value,
   if (change)
     nocheck_register_item_tree_change(place, change->old_value,
                                       runtime_memroot);
+  DBUG_VOID_RETURN;
 }
 
 
@@ -2250,17 +2254,13 @@ void THD::rollback_item_tree_changes()
 {
   I_List_iterator<Item_change_record> it(change_list);
   Item_change_record *change;
-  DBUG_ENTER("rollback_item_tree_changes");
 
   while ((change= it++))
   {
-    DBUG_PRINT("info", ("revert %p -> %p",
-                        change->old_value, (*change->place)));
     *change->place= change->old_value;
   }
   /* We can forget about changes memory: it's allocated in runtime memroot */
   change_list.empty();
-  DBUG_VOID_RETURN;
 }
 
 

sql/sql_class.h

@@ -2725,10 +2725,14 @@ class THD :public Statement,
 
   void change_item_tree(Item **place, Item *new_value)
   {
+    DBUG_ENTER("THD::change_item_tree");
+    DBUG_PRINT("enter", ("Register: %p (%p) <- %p",
+                       *place, place, new_value));
     /* TODO: check for OOM condition here */
     if (!stmt_arena->is_conventional())
       nocheck_register_item_tree_change(place, *place, mem_root);
     *place= new_value;
+    DBUG_VOID_RETURN;
   }
   /**
     Make change in item tree after checking whether it needs registering