aftermath on Bug 8953 – URL decomp. IDL attributes when parsing fails

See:

<http://www.w3.org/Bugs/Public/show_bug.cgi?id=8953>

So apparently WEBADDRESSES defines this

   <http://a[b].example.org/>

- to be a "URL" <http://dev.w3.org/html5/spec/infrastructure.html#url>

- not to be a "valid URL", but

- although being absolute according to common sense, *not* to be an 
"absolute URL".

Thus, it requires UAs to return empty strings for the various URL 
decomposition IDL attribute (see 
<http://dev.w3.org/html5/spec/infrastructure.html#interfaces-for-url-manipulation>)

According to my tests at 
<http://greenbytes.de/tech/webdav/urldecomp.html>, not a single UA 
implements this.

The closest ones to get this right are Safari and Chrome, which still 
get two of the attributes wrong.

The other UAs do not seem to consider the address as broken, and thus 
handle it like other HTTP URIs.

So, here's the question: why do we have this special constraint on [ and 
] in the authority component? Do UA implementors actually *agree* that 
this is the right thing to do?

Best regards, Julian