From 72ca8d1730c9468516257672cba3c79129048588 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Thu, 2 Feb 2017 12:48:49 -0500
Subject: [PATCH] Bug 1335654 part 2.  Change the deny() methods of our wrapper
 security policies to take a JSContext and a mayThrow boolean. r=bholley

---
 js/xpconnect/wrappers/AccessCheck.cpp      |  6 ++++--
 js/xpconnect/wrappers/AccessCheck.h        | 12 ++++++++----
 js/xpconnect/wrappers/FilteringWrapper.cpp |  3 ++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/js/xpconnect/wrappers/AccessCheck.cpp b/js/xpconnect/wrappers/AccessCheck.cpp
index 085e7100ef87..43f6c63f1ae9 100644
--- a/js/xpconnect/wrappers/AccessCheck.cpp
+++ b/js/xpconnect/wrappers/AccessCheck.cpp
@@ -441,13 +441,15 @@ ExposedPropertiesOnly::check(JSContext* cx, HandleObject wrapper, HandleId id, W
 }
 
 bool
-ExposedPropertiesOnly::deny(js::Wrapper::Action act, HandleId id)
+ExposedPropertiesOnly::deny(JSContext* cx, js::Wrapper::Action act, HandleId id,
+                            bool mayThrow)
 {
     // Fail silently for GET, ENUMERATE, and GET_PROPERTY_DESCRIPTOR.
     if (act == js::Wrapper::GET || act == js::Wrapper::ENUMERATE ||
         act == js::Wrapper::GET_PROPERTY_DESCRIPTOR)
     {
-        AutoJSContext cx;
+        // Note that ReportWrapperDenial doesn't do any _exception_ reporting,
+        // so we want to do this regardless of the value of mayThrow.
         return ReportWrapperDenial(cx, id, WrapperDenialForCOW,
                                    "Access to privileged JS object not permitted");
     }
diff --git a/js/xpconnect/wrappers/AccessCheck.h b/js/xpconnect/wrappers/AccessCheck.h
index 488cceac0e23..7e4e356e9e9c 100644
--- a/js/xpconnect/wrappers/AccessCheck.h
+++ b/js/xpconnect/wrappers/AccessCheck.h
@@ -49,7 +49,8 @@ struct Opaque : public Policy {
     static bool check(JSContext* cx, JSObject* wrapper, jsid id, js::Wrapper::Action act) {
         return false;
     }
-    static bool deny(js::Wrapper::Action act, JS::HandleId id) {
+    static bool deny(JSContext* cx, js::Wrapper::Action act, JS::HandleId id,
+                     bool mayThrow) {
         return false;
     }
     static bool allowNativeCall(JSContext* cx, JS::IsAcceptableThis test, JS::NativeImpl impl) {
@@ -62,7 +63,8 @@ struct OpaqueWithCall : public Policy {
     static bool check(JSContext* cx, JSObject* wrapper, jsid id, js::Wrapper::Action act) {
         return act == js::Wrapper::CALL;
     }
-    static bool deny(js::Wrapper::Action act, JS::HandleId id) {
+    static bool deny(JSContext* cx, js::Wrapper::Action act, JS::HandleId id,
+                     bool mayThrow) {
         return false;
     }
     static bool allowNativeCall(JSContext* cx, JS::IsAcceptableThis test, JS::NativeImpl impl) {
@@ -79,7 +81,8 @@ struct CrossOriginAccessiblePropertiesOnly : public Policy {
     static bool check(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id, js::Wrapper::Action act) {
         return AccessCheck::isCrossOriginAccessPermitted(cx, wrapper, id, act);
     }
-    static bool deny(js::Wrapper::Action act, JS::HandleId id) {
+    static bool deny(JSContext* cx, js::Wrapper::Action act, JS::HandleId id,
+                     bool mayThrow) {
         // Silently fail for enumerate-like operations.
         if (act == js::Wrapper::ENUMERATE)
             return true;
@@ -95,7 +98,8 @@ struct CrossOriginAccessiblePropertiesOnly : public Policy {
 struct ExposedPropertiesOnly : public Policy {
     static bool check(JSContext* cx, JS::HandleObject wrapper, JS::HandleId id, js::Wrapper::Action act);
 
-    static bool deny(js::Wrapper::Action act, JS::HandleId id);
+    static bool deny(JSContext* cx, js::Wrapper::Action act, JS::HandleId id,
+                     bool mayThrow);
     static bool allowNativeCall(JSContext* cx, JS::IsAcceptableThis test, JS::NativeImpl impl) {
         return false;
     }
diff --git a/js/xpconnect/wrappers/FilteringWrapper.cpp b/js/xpconnect/wrappers/FilteringWrapper.cpp
index ac46eae37477..7ad7f3b42c7e 100644
--- a/js/xpconnect/wrappers/FilteringWrapper.cpp
+++ b/js/xpconnect/wrappers/FilteringWrapper.cpp
@@ -196,7 +196,8 @@ FilteringWrapper<Base, Policy>::enter(JSContext* cx, HandleObject wrapper,
                                       bool mayThrow, bool* bp) const
 {
     if (!Policy::check(cx, wrapper, id, act)) {
-        *bp = JS_IsExceptionPending(cx) ? false : Policy::deny(act, id);
+        *bp = JS_IsExceptionPending(cx) ?
+            false : Policy::deny(cx, act, id, mayThrow);
         return false;
     }
     *bp = true;