[libxml-devel] Specifying namespace on XPath?

[keisuke fukuda]

Hi,

How to specify namespace on xpath in version 5.2.0 ?

Someone told me that you can do it like this in version 3.8.4 :
---
require "rubygems"
require "xml/libxml" # 3.8.4

doc = XML::Parser.string(<<EOS).parse
<?xml version="1.0" encoding='utf-8'?>
<service xmlns="http://www.w3.org/2007/app"
         xmlns:atom="http://www.w3.org/2005/Atom">
  <workspace>
    <collection href="http://example.org/blog/main">
      <atom:title>My Blog Entries</atom:title>
    </collection>
  </workspace>
</service>
EOS

namespaces =  {
  "app" => "http://www.w3.org/2007/app",
  "atom" => "http://www.w3.org/2005/Atom"
}.to_a

p doc.find('/app:service/app:workspace/app:collection/atom:title', namespaces)
__END__

=> <atom:title>My Blog Entries</atom:title>

---

But, in 5.2.0, it saids
" in `find': nested array must be an array of strings, prefix and
href/uri (ArgumentError) "

( in Addition, it  SEGVs sometimes in normal interpreter and always in irb )

Is this a bug ? (Or, is there any other way to do this in 5.2.0) ?
I took a look at the source code and found that  there is almost no
unit test about namespace on XPath.

-- 
FUKUDA, Keisuke