Right now, a lot of test code relies on side-effects of SpecialPowers being
loaded into frame script globals. In particular:
- It forces permissive COWs from those scopes, which allows frame scripts to
pass objects from those scopes to unprivileged content that they otherwise
wouldn't.
- It imports a bunch of helper modules and WebIDL globals which would
otherwise not be available.
Fortunately, this seems to only impact test code at this point. But there's a
real down-the-road risk of it impacting shipping code, which ends up working
in automation due to the side-effects of SpecialPowers, but failing in real
world use.
MozReview-Commit-ID: G27eSSOHymX
--HG--
extra : rebase_source : 1702e63fed719fc92def2bdbbb8a7c53572432db
extra : source : 41bedc526dd6ec6b7e8c7be1c832ac60c81d6263
Right now, a lot of test code relies on side-effects of SpecialPowers being
loaded into frame script globals. In particular:
- It forces permissive COWs from those scopes, which allows frame scripts to
pass objects from those scopes to unprivileged content that they otherwise
wouldn't.
- It imports a bunch of helper modules and WebIDL globals which would
otherwise not be available.
Fortunately, this seems to only impact test code at this point. But there's a
real down-the-road risk of it impacting shipping code, which ends up working
in automation due to the side-effects of SpecialPowers, but failing in real
world use.
MozReview-Commit-ID: G27eSSOHymX
--HG--
extra : rebase_source : c528dffe3a54eec75ad6cb358980b783b00eb4a4
