Nokogiri clobbers LibXML's error handlers

gistfile1.txt

describe "Nokogiri & LibXML interaction" do

  it "LibXML's error handler should not be clobbered by Nokogiri::XSLT(...)" do
    malformed_xml = '<?xml version="1.0" encoding="utf-8"?>
          <some_tag>
          </some_tag_with_typo>'

    xslt = '<?xml version="1.0" ?>
            <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
            <xsl:template match="product">
            </xsl:template>'
    begin
      # Comment out this line and the spec passes.
      Nokogiri::XSLT(StringIO.new(xslt))    
    rescue Exception
    end
    errors = []
    LibXML::XML::Error.set_handler do |foo|
      errors << foo
    end
    reader = LibXML::XML::Reader.io(StringIO.new(malformed_xml))
    begin
      while reader.read
      end
    rescue
    end
    errors.size.should == 1
  end
end