Use default character set for expressions

- Force usage of () around complex DEFAULT expressions
- Give error if DEFAULT expression contains invalid characters
- Don't use const_charset_conversion for stored Item_func_sysconf expressions
  as the result is not constaint over different executions
- Fixed Item_func_user() to not store calculated value in str_value

1 files changed, 4 insertions, 4 deletions

diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index aa7fabbdb21..e484e41d300 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -562,10 +562,7 @@ class Item_func_sysconst :public Item_str_func
 public:
   Item_func_sysconst(THD *thd): Item_str_func(thd)
   { collation.set(system_charset_info,DERIVATION_SYSCONST); }
-  Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs)
-  {
-    return const_charset_converter(thd, tocs, true, fully_qualified_func_name());
-  }
+  Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs);
   /*
     Used to create correct Item name in new converted item in
     safe_charset_converter, return string representation of this function
@@ -599,6 +596,7 @@ class Item_func_user :public Item_func_sysconst
 {
 protected:
   query_id_t last_query_id;
+  String cached_value;
   bool init(THD *thd, const char *user, const char *host);
 
 public:
@@ -906,6 +904,7 @@ public:
   }
   virtual void print(String *str, enum_query_type query_type);
   const char *func_name() const { return "cast_as_binary"; }
+  bool need_parentheses_in_default() { return true; }
 };
 
 
@@ -1058,6 +1057,7 @@ public:
     /* this function is transparent for view updating */
     return args[0]->field_for_view_update();
   }
+  bool need_parentheses_in_default() { return true; }
 };