[whatwg] Clarification on @srcdoc referrer and base URL

[Justin Schuh]

What should the baseURL and referrer be for a @srcdoc nested browsing
context? If I follow the base URL behavior for about:blank it will
just be inherited from the creator document. That seems like the right
thing to do, so I think section 2.5.1 should be modified to read:

"If fallback base url is about:blank or about:srcdoc, and the
Document's browsing context has a creator browsing context, then let
fallback base url be the document base URL of the creator Document
instead."

The referrer seems trickier. I couldn't find the about:blank referrer
behavior specified anywhere, and in my testing it does not inherit the
creator document's referrer. However, it seems to me that maybe
about:srcdoc should, even if about:blank does not.

Regards,
Justin