From: Vincent Isambart <vincent.isambart@...>
Date: 2007-08-25T17:22:32+09:00
Subject: String#length not working properly in Ruby 1.9

I saw that Matz just merged his M17N implementation in the trunk.
However, the length method of String does not work as it should:

# -*- coding: utf-8 -*-
a = 'あ'
p a.encoding
p a.length
p a.__send__(:length)

displays:

"UTF-8"
3
1

String#size does work fine. The problem comes from the fact that the
VM has a length instruction that has its own implementation of the
String length. A quick fix was to remove it as does the patch below.
An other way to fix would be to reimplement it correctly using the
encoding aware methods.

Index: insns.def
===================================================================
--- insns.def   (revision 13268)
+++ insns.def   (working copy)
@@ -1954,9 +1954,6 @@
        if (HEAP_CLASS_OF(recv) == rb_cArray) {
            val = LONG2NUM(RARRAY_LEN(recv));
        }
-       else if (HEAP_CLASS_OF(recv) == rb_cString) {
-           val = LONG2NUM(RSTRING_LEN(recv));
-       }
        else if (HEAP_CLASS_OF(recv) == rb_cHash) {
            val = INT2FIX(RHASH(recv)->tbl->num_entries);
        }