Why is same-document reference in SVG affected by HTML <base> tag?

I have an HTML page with a <base> tag, also containing SVG. Same-document references such as the below within the SVG then fail:

<html>
  <head>
    <base href="http://my/server/basedir">
  </head>
  <body>
    <svg>
      <g>
        <path d="M100,100 L150,150" id="path"/>
        <text>
          <textpath xlink:href="#path"/>
        </text>
      </g>
    </svg>
  </body>
</html>

The xlink:href="#path" reference fails to resolve. This works fine without the HTML base element. It also works if I replace the href attribute on the textpath element with an absolute IRI followed by the fragment identifier.

It seems to me that SVG should treat same-document IRI's differently and independent of the HTML base. In http://www.w3.org/TR/xmlbase/#same-document it says "Dereferencing of same-document references is handled specially.", although granted that's in the context of xml:base. By the way, I played with putting an xml:base on the svg element in hopes of overriding the HTML base setting for couldn't figure out how to make that work.

<html> <head> <base href="http://my/server/basedir"> </head> <body> <svg width="300" height="300" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <g> <path d="M100,100 L150,150" id="path"/> <text> <textpath xlink:href="#path">Hello</textpath> </text> </g> </svg> </body> </html>

<html> <head> <base href="http://my/server/basedir"> </head> <body> <svg width="300" height="300" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:base="http://my/thisfile.htm"> <g> <path d="M100,100 L150,150" id="path"/> <text> <textpath xlink:href="#path">Hello</textpath> </text> </g> </svg> </body> </html>

Recommended topics

Hot tags