Ruby: libxml-ruby and adding nicely-formatted sibling nodes

Question

Given my existing XML (test.xml):

<root>
  <element>
    <child id="1" />
    <child id="2" />
    <child id="3" />
  </element>
</root>

And my ruby code:

require 'rubygems'
require 'xml'

parser = XML::Parser.file("test.xml")
doc = parser.parse

target = doc.find('/*/element')
target << child = XML::Node.new('child')
child['id'] = '4'

XML.indent_tree_output = true
doc.save(filename, :indent => true, :encoding => XML::Encoding::UTF_8)

My problem is that it formats the output like this:

<root>
  <element>
    <child id="1" />
    <child id="2" />
    <child id="3" />
  <child id="4" /></element>
</root>

... with subsequent additions looking like this:

<root>
  <element>
    <child id="1" />
    <child id="2" />
    <child id="3" />
  <child id="4" /><child id="5" /><child id="6" /></element>
</root>

What I WANT is this:

<root>
  <element>
    <child id="1" />
    <child id="2" />
    <child id="3" />
    <child id="4" />
    <child id="5" />
    <child id="6" />
  </element>
</root>

... but how do I get it?

Answer 1

replace
parser = XML::Parser.file("test.xml")

with
parser = XML::Parser.file("test.xml", :options => XML::Parser::Options::NOBLANKS )

that's help