From: Vincent Isambart <redmine@...>
Date: 2010-01-24T12:10:46+09:00
Subject: [ruby-core:27748] [Bug #2636] Incorrect UTF-16 string length

Bug #2636: Incorrect UTF-16 string length
http://redmine.ruby-lang.org/issues/show/2636

Author: Vincent Isambart
Status: Open, Priority: Normal
Category: M17N, Target version: 1.9.2
ruby -v: ruby 1.9.2dev (2010-01-22 trunk 26370) [x86_64-darwin10.2.0]

str = "\xDC\x0B\xD8\x40".force_encoding(Encoding::UTF_16BE)
str.length #=> 3

This string is made by inverting 2 words of a UTF-16 character not in the BMP.
The length should be 2 because it's made of two (unpaired) surrogates and not 3.

The most strange part is that even though the length concurs with how the string is displayed when doing #inspect ("\xDC\u0BD8\x40"), but not with what #[] does. If the length is 3, then why does str[2] return nil?


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