[whatwg] Base URL’s effect on an empty @src element

[Leif Halvard Silli]

Given a document, where 

 1. the content of img @src is empty, and thus invalid, 
 2. but there is base url which points to an image
 
 Example:
  <!DOCUMENT html>
  <base href="image.jpg"/>
  <img src="" alt="Text." />

  Live DOM Viewer test:
  http://software.hixie.ch/utilities/js/live-dom-viewer/saved/2236
   
Current UA behaviors:
 x) Firefox is the only one to render it the image 'image.jpg'.
 y) Webkit/Blink, IE10 and Opera12 render it as the alt text.

Questions:
 A) Which of x) and y) is correct?
 B) If the correct behavior is already defined in a spec,
    where is it defined?

Leif Halvard Silli