1 files changed, 43 insertions, 19 deletions

diff --git a/sql/item.h b/sql/item.h
index d5f0dfec033..863265a73f7 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -2,7 +2,7 @@
 #define SQL_ITEM_INCLUDED
 
 /* Copyright (c) 2000, 2015, Oracle and/or its affiliates.
-   Copyright (c) 2009, 2015, MariaDB
+   Copyright (c) 2009, 2016, MariaDB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -430,7 +430,7 @@ public:
 
     RETURN
       FALSE if parameter value has been set,
-      TRUE if error has occured.
+      TRUE if error has occurred.
   */
   virtual bool set_value(THD *thd, sp_rcontext *ctx, Item **it)= 0;
 
@@ -663,9 +663,7 @@ protected:
   Field *tmp_table_field_from_field_type(TABLE *table,
                                          bool fixed_length,
                                          bool set_blob_packlength);
-  Field *create_tmp_field(bool group, TABLE *table,
-                          uint convert_blob_length,
-                          uint convert_int_length);
+  Field *create_tmp_field(bool group, TABLE *table, uint convert_int_length);
 
 public:
   /*
@@ -1665,16 +1663,13 @@ public:
   // used in row subselects to get value of elements
   virtual void bring_value() {}
 
-  virtual Field *create_tmp_field(bool group, TABLE *table,
-                                  uint convert_blob_length)
+  virtual Field *create_tmp_field(bool group, TABLE *table)
   {
     /*
       Values with MY_INT32_NUM_DECIMAL_DIGITS digits may or may not fit into
       Field_long : make them Field_longlong.
     */
-    return create_tmp_field(false, table,
-                            convert_blob_length,
-                            MY_INT32_NUM_DECIMAL_DIGITS - 2);
+    return create_tmp_field(false, table, MY_INT32_NUM_DECIMAL_DIGITS - 2);
   }
 
   virtual Item_field *field_for_view_update() { return 0; }
@@ -2743,7 +2738,7 @@ public:
 
   /*
     If value for parameter was not set we treat it as non-const
-    so noone will use parameters value in fix_fields still
+    so no one will use parameters value in fix_fields still
     parameter is constant during execution.
   */
   virtual table_map used_tables() const
@@ -3688,6 +3683,11 @@ public:
     used_tables_cache|= item->used_tables();
     const_item_cache&= item->const_item();
   }
+  void used_tables_and_const_cache_update_and_join(Item *item)
+  {
+    item->update_used_tables();
+    used_tables_and_const_cache_join(item);
+  }
   /*
     Call update_used_tables() for all "argc" items in the array "argv"
     and join with the current cache.
@@ -3697,10 +3697,7 @@ public:
   void used_tables_and_const_cache_update_and_join(uint argc, Item **argv)
   {
     for (uint i=0 ; i < argc ; i++)
-    {
-      argv[i]->update_used_tables();
-      used_tables_and_const_cache_join(argv[i]);
-    }
+      used_tables_and_const_cache_update_and_join(argv[i]);
   }
   /*
     Call update_used_tables() for all items in the list
@@ -3713,10 +3710,7 @@ public:
     List_iterator_fast<Item> li(list);
     Item *item;
     while ((item=li++))
-    {
-      item->update_used_tables();
-      used_tables_and_const_cache_join(item);
-    }
+      used_tables_and_const_cache_update_and_join(item);
   }
 };
 
@@ -5161,6 +5155,12 @@ public:
     return (this->*processor)(arg);
   }
   virtual Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs);
+  void split_sum_func2_example(THD *thd,  Ref_ptr_array ref_pointer_array,
+                               List<Item> &fields, uint flags)
+  {
+    example->split_sum_func2(thd, ref_pointer_array, fields, &example, flags);
+  }
+  Item *get_example() const { return example; }
 };
 
 
@@ -5265,6 +5265,30 @@ public:
   bool cache_value();
 };
 
+
+class Item_cache_str_for_nullif: public Item_cache_str
+{
+public:
+  Item_cache_str_for_nullif(THD *thd, const Item *item)
+   :Item_cache_str(thd, item)
+  { }
+  Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs)
+  {
+    /**
+      Item_cache_str::safe_charset_converter() returns a new Item_cache
+      with Item_func_conv_charset installed on "example". The original
+      Item_cache is not referenced (neither directly nor recursively)
+      from the result of Item_cache_str::safe_charset_converter().
+
+      For NULLIF() purposes we need a different behavior:
+      we need a new instance of Item_func_conv_charset,
+      with the original Item_cache referenced in args[0]. See MDEV-9181.
+    */
+    return Item::safe_charset_converter(thd, tocs);
+  }
+};
+
+
 class Item_cache_row: public Item_cache
 {
   Item_cache  **values;