Created attachment 221889 [details]
The SVG Image
When the SVG is view directly by the browser, it displays correctly. When it is displayed via an HTML img element, the image within the SVG disappears.
Created attachment 221890 [details]
The test HTML file that shows the issue.
Additional testing shows that it doesn't work properly in Safari Version 7.0.1 (9537.73.11) but does in Chrome Version 32.0.1700.77 ... although that has forked from WebKit now.
Updated external test case: https://thefiletree.com/gh-badges/button.html?plug=none
As shown, having the <image> in an SVG works inline, in embed, in object, in iframe, but not in an <img>.
Only data uri images are allowed as sub-resources in SVGs.
*** This bug has been marked as a duplicate of bug 99677 ***