win32/file.c: refine fix_string_encoding

* win32/file.c (fix_string_encoding): simplify with rb_str_conv_enc().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42180 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,6 @@
-Fri Jul 26 13:00:24 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Fri Jul 26 13:01:04 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* win32/file.c (fix_string_encoding): simplify with rb_str_conv_enc().
 
 	* win32/file.c (convert_mb_to_wchar): use bare pointer instead of
 	  VALUE, and remove useless argument.

win32/file.c

@@ -235,16 +235,7 @@ code_page(rb_encoding *enc)
     return INVALID_CODE_PAGE;
 }
 
-static inline VALUE
-fix_string_encoding(VALUE str, rb_encoding *encoding)
-{
-    VALUE result, tmp;
-
-    tmp = rb_enc_str_new(RSTRING_PTR(str), RSTRING_LEN(str), encoding);
-    result = rb_str_encode(tmp, rb_enc_from_encoding(rb_utf8_encoding()), 0, Qnil);
-
-    return result;
-}
+#define fix_string_encoding(str, encoding) rb_str_conv_enc((str), NULL, (encoding))
 
 /*
   Replace the last part of the path to long name.