1133085 - PropDesc::initFromPropertyDescriptor fills in get or set if only the other is present

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jason Orendorff [:jorendorff]]

That is: if the PropertyDescriptor has just JSPROP_SETTER, the resulting PropDesc will have both .hasGet() and .hasSet() true. It's observable from script:


var p = new Proxy({}, {
    defineProperty(t, k, desc) {
        assertEq("get" in desc, false);  // FAILS
    }
});
Object.defineProperty(p, "x", {set: function () {}});

Comment 1

[Jason Orendorff [:jorendorff]]

Attachment: Fix for PropDesc::initFromPropertyDescriptor

PropDesc and PropertyDescriptor are at last capable of expressing all valid PropertyDescriptors, both complete and incomplete. This should make them pretty much equivalent. But since this came on gradually, there is a lingering bug in the code that translates between the two structs.

Comment 2

[Eric Faust [:efaust]]

Comment on attachment 8565091 [details] [diff] [review]
Fix for PropDesc::initFromPropertyDescriptor

Review of attachment 8565091 [details] [diff] [review]:
-----------------------------------------------------------------

Sure. This makes sense in light of everything else.

Comment 3

[Jason Orendorff [:jorendorff]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/2bc1b90f74a7

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/2bc1b90f74a7