1034239 - Switch the current GentlyOpaque security wrapper to an Opaque XrayTrait

Status: RESOLVED FIXED

(Core :: XPConnect, defect)

Description

[Bobby Holley (:bholley)]

I did this wrong before. Making this a SecurityWrapper means that the caller does not subsumes the target, and that the target therefore needs to be protected from the caller. But GentlyOpaque was supposed to be an analog of PermissiveXray for use when no useful XrayTraits exist, so it should behave similarly.
    
If we make this a Filtering Security Wrapper, we get a bunch of assertions where we expect CheckedUnwrap to succeed for a chrome-side wrapper. And we can't making it a Filtering Non-Security Wrapper, because then the filtering policy isn't even consulted (an optimization in jsproxy.cpp).
    
Really, we want all of the Xray machinery (like the ability to waive and to place expandos), and we just don't want to resolve any properties. This patches in this bug will do that.

Comment 1

[Bobby Holley (:bholley)]

https://tbpl.mozilla.org/?tree=Try&rev=12f428daa375

Comment 2

[Bobby Holley (:bholley)]

Attachment: Part 1 - Add Proxies to ForceCOWBehavior. v1

Comment 3

[Bobby Holley (:bholley)]

Attachment: Part 2 - Replace GentlyOpaque with an "Xray-to-nothing" wrapper. v2

I did this wrong before. Making this a SecurityWrapper means that the caller does
not subsumes the target, and that the target therefore needs to be protected
from the caller. But GentlyOpaque was supposed to be an analog of PermissiveXray
for use when no useful XrayTraits exist, so it should behave similarly.

If we make this a Filtering Security Wrapper, we get a bunch of assertions where we
expect CheckedUnwrap to succeed for a chrome-side wrapper. And we can't making it
a Filtering Non-Security Wrapper, because then the filtering policy isn't even
consulted (an optimization in jsproxy.cpp).

Really, we want all of the Xray machinery (like the ability to waive and to place
expandos), and we just don't want to resolve any properties. This patch does this.

Comment 4

[Bobby Holley (:bholley)]

remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/31ac9fc7c668
remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/fd0234ab4582

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/31ac9fc7c668
https://hg.mozilla.org/mozilla-central/rev/fd0234ab4582