Nokogiri::XML::Builder doesn't support "-" (hyphens) in namespace prefixes

[parameme]

While trying to get a .Net bug-compatible SOAP output I found the following anomaly...

require 'nokogiri'

SOAP_NAMESPACES =  {
                        "xmlns:SOAP-ENV"=>"http://schemas.xmlsoap.org/soap/envelope/",
                        "xmlns:SOAP-ENC"=>"http://www.w3.org/2003/05/soap-encoding",
                        "xmlns:xsi"=>"http://www.w3.org/2001/XMLSchema-instance",
                        "xmlns:xsd"=>"http://www.w3.org/2001/XMLSchema",
                        "xmlns:wsa"=>"http://schemas.xmlsoap.org/ws/2004/08/addressing",
                        "xmlns:custom"=>"http://local.dev/soap_api/v1"
                   }


# Namespaces explicitly post constructed
builder = Nokogiri::XML::Builder.new( :encoding => 'UTF-8' ) do |xml|
  xml.Envelope do
    #Workaround to allow namespace prefixes with "-" (hyphens) in them
    SOAP_NAMESPACES.each do | prefix, href |
      xml.doc.root.add_namespace_definition( prefix.gsub( 'xmlns:', '' ), href )
    end
    #Workaround to allow SOAP envelope to be namespaced after namespace defined
    xml.doc.root.namespace = xml.doc.root.namespace_definitions.first
  end
end

puts "Expected Output :"
puts builder.doc.to_xml

# Namespaces inline with root element
builder = Nokogiri::XML::Builder.new( :encoding => 'UTF-8' ) do |xml|
  xml.Envelope(
                SOAP_NAMESPACES
              ) do
    #Workaround to allow SOAP envelope to be namespaced after namespace defined
    xml.doc.root.namespace = xml.doc.root.namespace_definitions.first
  end
end

puts "Actual Output :"
puts builder.doc.to_xml

Expected Output :

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:custom="http://local.dev/soap_api/v1"/>

Actual Output :

<?xml version="1.0" encoding="UTF-8"?>
<xsi:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:custom="http://local.dev/soap_api/v1" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding"/>

If reasonable I think it should be a simple regex change in nokogiri-1.5.0/lib/nokogiri/xml/document.rb (around line : 60)

            arg.each { |k,v|
              key = k.to_s
              if key =~ /^xmlns(:\w+)?$/  #Change "\w+" to "[0-9A-Za-z_-]+" or whatever is XML NCName compliant
                ns_name = key.split(":", 2)[1]
                elm.add_namespace_definition ns_name, v
                next
              end
              elm[k.to_s] = v.to_s
            }

Regards,
parameme