Inconsistent namespaced attribute access for SVG nested in HTML

[mikepfirrmann]

Nokogiri::XML::Node.[] and Nokogiri::XML::Node.attribute return different values for namespaced attributes of SVGs nested within HTML documents.

For example, if you call try and access the value of the xlink:href attribute of a nested SVG image node, image["xlink:href"] returns nil while image.attribute("xlink:href") will return the actual value.

This issue appears to affect versions 1.5.6 and above.

Demonstration script

[flavorjones]

@ender672 - thanks for the fix. Please remember to edit the CHANGELOG files, though!

[ender672]

Will do!