[whatwg] Methods defined for one document called after that document is no longer the one being displayed

Jonas Sicking jonas at sicking.cc
Thu Feb 12 22:28:47 PST 2009

On Thu, Feb 12, 2009 at 7:15 PM, Ian Hickson <ian at hixie.ch> wrote:
> On Sat, 31 Jan 2009, Boris Zbarsky wrote:
>> Ian Hickson wrote:
>> > I haven't mentioned the 'this' behavior, so right now |this !===
>> > window|, which breaks the invariant that there is no way to actually
>> > get hold of a reference to the Window object itself (as opposed to the
>> > outer WindowProxy object that forwards to the inner Window object).
>> > This requirement would be a violation of ECMAScript 3.1, so if we
>> > could get that changed in ES3.1, that would be great. Failing that, it
>> > should probably be in the WebIDL JavaScript binding section.
>> As I recall, in Gecko the keyword |this| evaluates to the outer window.
>> I'm not sure what happens to the implicit |this| that's computed when
>> defining a global function, say.
>> The reason for this setup was precisely to prevent script from getting a
>> handle to the inner Window.  Since we do security checks for cross-site
>> scripting in the outer Window, any ability to pass inner Windows
>> cross-site would be an automatic security hole.
>> The setup as it exists right now allows scripts that run within a single
>> window and never explicitly touch Window objects to not have to perform
>> security checks on every property access.
>> You might want to double-check with Blake Kaplan, Brendan Eich, or
>> Johnny Stenback on the above, as well as on how this fits in with
>> ECMAScript 3.1.  I seem to recall something about that going by in the
>> bugs when this was being worked on, but Brendan is more likely to recall
>> the details than I am to be able to find them...
> I've pinged Brendan about this, but on the short term, I've put the
> requirement in HTML5, so that we don't lose it.

cc'ing a couple of people that are intimately familiar with how the
split-window implementation works in gecko.

/ Jonas

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