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

Ian Hickson ian at hixie.ch
Thu Feb 12 19:15:42 PST 2009

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.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

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