[whatwg] Empty <html manifest=""> attribute handling.

Fri Jul 31 13:24:26 PDT 2009

Hello,

How empty <html manifest=""> attribute values are handled in the
section 9.2.5.5 may want some massaging.

http://www.whatwg.org/specs/web-apps/current-work/multipage/syntax.html#parser-appcache

> If the Document is being loaded as part of navigation of a browsing context, then: if the newly
> created element has a manifest attribute, then resolve the value of that attribute to an absolute
> URL, relative to the newly created element, and if that is successful, run the application cache
> selection algorithm with the resulting absolute URLwith any <fragment> component removed;
> otherwise, if there is no such attribute or resolving it fails, run the application cache selection
> algorithm with no manifest. The algorithm must be passed the Document object.

This ends up passing the value of the document url into the cache
selection algorithm as the manifest url,
which will initiate an update and all that.

A couple of things that may make sense.

1) equate <html manifest=""> with <html>.... treat empty as non-existent.

2) don't resolve the url if the attribute value is empty, pass an
empty url to the cache selection algorithm,
and have that algorithm flag such resources as foreign if it was
loaded from an appcache

Both of these prevent the initiation of an update that is doomed to fail.