New CHARSET() function

sql/item_strfunc.cc

@@ -1911,12 +1911,25 @@ outp:
   return str;
 }
 
+String *Item_func_charset::val_str(String *str)
+{
+  String *res = args[0]->val_str(str);
+
+  if ((null_value=(args[0]->null_value || !res->charset())))
+    return 0;
+  str->copy(res->charset()->name,strlen(res->charset()->name));
+  return str;
+}
+
+
 void Item_func_conv_charset3::fix_length_and_dec()
 {
   /* BAR TODO: What to do here??? */
 }
 
 
+
+
 String *Item_func_hex::val_str(String *str)
 {
   if (args[0]->result_type() != STRING_RESULT)

sql/item_strfunc.h

@@ -503,6 +503,18 @@ public:
   const char *func_name() const { return "conv_charset3"; }
 };
 
+class Item_func_charset :public Item_str_func
+{
+public:
+  Item_func_charset(Item *a) :Item_str_func(a) {}
+  String *val_str(String *);
+  const char *func_name() const { return "charset"; }
+  void fix_length_and_dec() 
+  {
+     max_length=20; // should be enough
+  };
+};
+
 
 /*******************************************************
 Spatial functions

sql/sql_yacc.yy

@@ -1784,6 +1784,8 @@ simple_expr:
 	  { $$= new Item_func_atan($3,$5); }
 	| CHAR_SYM '(' expr_list ')'
 	  { $$= new Item_func_char(*$3); }
+	| CHARSET '(' expr ')'
+	  { $$= new Item_func_charset($3); }
 	| COALESCE '(' expr_list ')'
 	  { $$= new Item_func_coalesce(* $3); }
 	| CONCAT '(' expr_list ')'