Status: New
Owner: ----
New issue 1547 by [email protected]: Wrong global in cross-frame
this-coercion
http://code.google.com/p/v8/issues/detail?id=1547
The attached file renders
(1,f)(): inner
on Chrome 14.0.803.0 dev, whereas it renders
(1,f)(): outer
as it should on Safari Version 5.0.5 (5533.21.1), WebKit Nightly Version
5.0.5 (5533.21.1, r90681), Firefox 5.0, and Firefox Nightly 8.0a1
(2011-07-09).
Technically, this issue falls between the gaps of various specs, since the
ES5.1 spec does not admit the existence of multiple globals. Nevertheless,
from the perspective of ES5.1 semantics, only the latter behavior makes
sense, since the caller passes undefined as the this-binding and only the
callee coerces the undefined to the global object. Since the callee does
not and should not know the caller's global object, the global object it
should coerce to is its own. This corresponds to a lexical understanding
of "which global", which is what ES-next is expected to specify.
Note that the similar https://bugzilla.mozilla.org/show_bug.cgi?id=634590
issue did arrive at the opposite result, that f() should return "inner".
This likewise makes no sense, as that bug thread admits, but is
unfortunately needed for backward compatibility. The nonsensical behavior
in this case is already a de-facto standard across as least all the same
browsers listed about, including Chrome. (I haven't yet tested any of this
on IE10preview.) But for (1,f)(), de-facto agreement among other browsers
agrees with sense, so we should fix Chrome to match.
See also the thread beginning at
https://mail.mozilla.org/pipermail/es5-discuss/2011-July/004018.html .
Please tag with ES5. Thanks.
Attachments:
inner-out2.html 220 bytes
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