Bug 1034244 - Hoist SpecialPowers Xray waiving into a separate function so that we can apply it at each stage when climbing the prototype chain. r=mrbkap

This commit is contained in:
Bobby Holley 2014-07-09 15:23:53 -07:00
parent 769638973e
commit eb8972c288

View File

@ -83,7 +83,30 @@ function isObjectOrArray(obj) {
return arrayClasses.indexOf(className) != -1;
}
// In general, we want Xray wrappers for content DOM objects, because waiving
// Xray gives us Xray waiver wrappers that clamp the principal when we cross
// compartment boundaries. However, there are some exceptions where we want
// to use a waiver:
//
// * Xray adds some gunk to toString(), which has the potential to confuse
// consumers that aren't expecting Xray wrappers. Since toString() is a
// non-privileged method that returns only strings, we can just waive Xray
// for that case.
//
// * We implement Xrays to pure JS [[Object]] and [[Array]] instances that
// filter out tricky things like callables. This is the right thing for
// security in general, but tends to break tests that try to pass object
// literals into SpecialPowers. So we waive [[Object]] and [[Array]]
// instances before inspecting properties.
function waiveXraysIfAppropriate(obj, propName) {
if (propName == 'toString' || isObjectOrArray(obj))
return XPCNativeWrapper.unwrap(obj);
return obj;
}
function callGetOwnPropertyDescriptor(obj, name) {
obj = waiveXraysIfAppropriate(obj, name);
// Quickstubbed getters and setters are propertyOps, and don't get reified
// until someone calls __lookupGetter__ or __lookupSetter__ on them (note
// that there are special version of those functions for quickstubs, so
@ -230,31 +253,13 @@ SpecialPowersHandler.prototype.doGetPropertyDescriptor = function(name, own) {
if (name == "__exposedProps__")
return { value: ExposedPropsWaiver, writable: false, configurable: false, enumerable: false };
// In general, we want Xray wrappers for content DOM objects, because waiving
// Xray gives us Xray waiver wrappers that clamp the principal when we cross
// compartment boundaries. However, there are some exceptions where we want
// to use a waiver:
//
// * Xray adds some gunk to toString(), which has the potential to confuse
// consumers that aren't expecting Xray wrappers. Since toString() is a
// non-privileged method that returns only strings, we can just waive Xray
// for that case.
//
// * We implement Xrays to pure JS [[Object]] and [[Array]] instances that
// filter out tricky things like callables. This is the right thing for
// security in general, but tends to break tests that try to pass object
// literals into SpecialPowers. So we waive [[Object]] and [[Array]]
// instances before inspecting properties.
var obj = this.wrappedObject;
if (name == 'toString' || isObjectOrArray(obj))
obj = XPCNativeWrapper.unwrap(obj);
//
// Call through to the wrapped object.
//
// Note that we have several cases here, each of which requires special handling.
//
var desc;
var obj = this.wrappedObject;
function isWrappedNativeXray(o) {
if (!Cu.isXrayWrapper(o))
return false;
@ -289,6 +294,7 @@ SpecialPowersHandler.prototype.doGetPropertyDescriptor = function(name, own) {
// we make up a descriptor, using some assumptions about what kinds of things
// tend to live on the prototypes of Xray-wrapped objects.
else {
obj = waiveXraysIfAppropriate(obj, name);
desc = Object.getOwnPropertyDescriptor(obj, name);
if (!desc) {
var getter = Object.prototype.__lookupGetter__.call(obj, name);