Jeff,
I think your real question reduces to this:
//none strict mode code
globalObj= function() {return this}();
print(otherGlobal.eval("this") === globalObj) //??
The two different calls and the "indirect" name in your example may make the
question seen like it is about something else (direct/indirect eval).
A more generally, do built-in functions capture their global environment at
the time of their creation or do they they operate in the dynamic context of an
ambient global environment. I hope it is the former.
An example of the more general question would be:
print((Object.getPrototypeOf(new otherGlobal.Array(0)) === Array.prototype)
I believe the second example prints false for all browser implementations.
Allen
On Mar 3, 2011, at 2:39 PM, Jeff Walden wrote:
> A few months back I noticed an interesting interaction between how direct
> eval is defined and multiple globals. What happens if, in one global, you
> call an eval from another global as if it were a direct eval?
>
> var indirect = otherGlobal.eval;
> eval = indirect;
> print(eval("this") === this);
> print(indirect("this") === this);
>
> Standards currently don't say what should happen here because it's multiple
> globals, so what should this do? IE9 and Opera print false both times for
> this. Firefox prints true, then false -- but only if the global and
> otherGlobal are from the same origin (so on pages with the same
> scheme/host/port, more or less). If they're from different origins (but have
> set document.domain to the same value) Firefox too prints false. Chrome and
> Safari throw an EvalError calling another window's eval (for both "direct"
> and indirect calls) without that window as |this| for the call.
>
> The Chrome/Safari behavior would resurrect the vestigial EvalError, so I
> don't think it makes sense. It also contradicts the specification of the
> steps in the definition of the eval function. Firefox's behavior is
> inconsistent and seems not amenable to host-agnostic specification as ECMA
> would require. Thus we are left with the IE9/Opera behavior, which seems
> sensible and natural to me: an eval function should always act in the context
> of the global from which it came.
>
> What needs to be done to standardize this behavior? And more generally, what
> needs to be done to begin standardizing multiple globals in ECMAScript,
> including issues like this one?
>
> Jeff
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