This is another one of those annoying situaitons in XPConnect right now where we
can't ask a question without potentially throwing if the answer is no. There's
also a bunch of unused cruft in here (like the Perm*Access stuff), so this stuff
was ripe for a spring cleaning. Unfortunately, I wasn't able to divide this patch
up nicely. Sorry for the big diff. :-(
In a nutshell, this patch changes things so that Policy::check() just becomes
a predicate that says whether the access is allowed or not. There's the remote
possibility that one of the underlying JSAPI calls in a ::check() implementation
might throw, so callers to ::check() should check JS_IsExceptionPending
afterwards (this doesn't catch OOM, but we can just continue along until the
next OOM-triggering operation and throw there).
Aside from exceptional cases, callers should call Policy::deny if they want to
report the failure. Policy::deny returns success value that should be returned
to the wrapper's consumer.
This is another one of those annoying situaitons in XPConnect right now where we
can't ask a question without potentially throwing if the answer is no. There's
also a bunch of unused cruft in here (like the Perm*Access stuff), so this stuff
was ripe for a spring cleaning. Unfortunately, I wasn't able to divide this patch
up nicely. Sorry for the big diff. :-(
In a nutshell, this patch changes things so that Policy::check() just becomes
a predicate that says whether the access is allowed or not. There's the remote
possibility that one of the underlying JSAPI calls in a ::check() implementation
might throw, so callers to ::check() should check JS_IsExceptionPending
afterwards (this doesn't catch OOM, but we can just continue along until the
next OOM-triggering operation and throw there).
Aside from exceptional cases, callers should call Policy::deny if they want to
report the failure. Policy::deny returns success value that should be returned
to the wrapper's consumer.
We want this right now so that we can avoid the scary warning when content Components
access happens in XBL (which we're allowing going forward). This patch would be overkill
just for that, but I also have plans to introduce a SOW-like protection of the Components
wrapper filtering policy. I can't just do the filename hack for that though, because real-
world XBL filenames might be all over the place. So let's just be safe here.
There are really two questions to be asked: is the caller chrome, and does the
caller subsume the callee. We have other, more precise ways of asking both of
these questions.
There are really two questions to be asked: is the caller chrome, and does the
caller subsume the callee. We have other, more precise ways of asking both of
these questions.
There are really two questions to be asked: is the caller chrome, and does the
caller subsume the callee. We have other, more precise ways of asking both of
these questions.
Now that we have nsExpandedPrincipal, the current way of doing things is wrong. For some reason, the old document.domain hackery was hiding the failures here.
