699945 - Make __proto__ configurable

Status: RESOLVED DUPLICATE of bug 770344

(Core :: JavaScript Engine, defect)

Description

[Jason Orendorff [:jorendorff]]

__proto__ would stop appearing to be an own property of every object that inherits from Object.prototype. (It appears that way now because of the shared-permanent hack, but nobody depends on it. We special-case object literals, like
{__proto__: null}, in the parser, turning the property initialization there into an assignment.)

Also it would be possible to delete it.

I think this is fine and the Caja folks would be thrilled. Actually maybe we should hold out for beer from the Caja team.

Nah.

Comment 1

[David Bruant]

Related strawman (discussion linked in the wiki): http://wiki.ecmascript.org/doku.php?id=strawman:magic_proto_property

Based on the discussions, it seems that being able to delete __proto__ would already be a tremendous win.

Comment 2

[Jason Orendorff [:jorendorff]]

The one-liner passes all the shell tests. Running mochitests now:
  https://tbpl.mozilla.org/?tree=Try&rev=18badd3a671a

Comment 3

[Jason Orendorff [:jorendorff]]

Appears to cause crashes. Awesome.

Comment 4

[Jeff Walden [:Waldo]]

This got fixed in bug 770344.