Re: [agenda] Web Performance WG Teleconference #28 Agenda 2011-04-13

    Thanks, Tony.

   iirc, some user agents always load the about:blank page before other url
on starting up.
Is that correct? If so, the statement from 4.2 does seem redundant. Or, I
think my real
question is, does "prompt to unload a document" always occur?

cheers,
Zhiheng

On Wed, Apr 20, 2011 at 9:50 AM, Tony Gentilcore <tonyg@google.com> wrote:

> On Wed, Apr 13, 2011 at 7:08 PM, Zhiheng Wang <zhihengw@google.com> wrote:
> > * If there is no previous document, navigationStart must return the same
> value as fetchStart. unloadEventStart/End must return 0.
>
> As promised on last week's call, I submitted a test for this. Please
> review:
>
> http://w3c-test.org/webperf/tests/submission/Google/NavigationTiming/test_no_previous_document.htm
>
> It only checks that unload times are 0, not that navigationStart ==
> fetchStart. I'd like to raise a issue/question about that.
>
> In section 4.2, the spec says "If there is no previous document, this
> attribute must return the same value as fetchStart." However, the more
> descriptive processing model (section 5.1) describes them being
> recorded as two distinct times. That sentence might typically be true
> when there are no 3xx redirects, but certainly isn't true for
> redirects. Even in the non-redirect case, if two distinct times are
> recorded back-to-back, there is a non-zero chance that the second one
> will be later than the first. I propose we stick with the processing
> model and drop that sentence from 4.2.
>
> -Tony
>