auto merge of #3693 : ehsan/servo/3248, r=jdm

This fixes #3248.

r? @jdm.  Please review for mistakes mercilessly!  Also, I got a host of test failures when running the worker tests, not sure if these tests are expected to pass locally or not.

components/script/dom/bindings/error.rs

@@ -34,7 +34,8 @@ pub enum Error {
     Security,
     Network,
     Abort,
-    Timeout
+    Timeout,
+    DataClone
 }
 
 /// The return type for IDL operations that can throw DOM exceptions.

components/script/dom/dedicatedworkerglobalscope.rs

@@ -7,6 +7,7 @@ use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding::Dedicat
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
 use dom::bindings::codegen::InheritTypes::DedicatedWorkerGlobalScopeDerived;
 use dom::bindings::codegen::InheritTypes::{EventTargetCast, WorkerGlobalScopeCast};
+use dom::bindings::error::{ErrorResult, DataClone};
 use dom::bindings::global;
 use dom::bindings::js::{JSRef, Temporary, RootCollection};
 use dom::bindings::utils::{Reflectable, Reflector};
@@ -25,7 +26,7 @@ use script_task::StackRootTLS;
 use servo_net::resource_task::{ResourceTask, load_whole_resource};
 
 use js::glue::JS_STRUCTURED_CLONE_VERSION;
-use js::jsapi::{JSContext, JS_ReadStructuredClone, JS_WriteStructuredClone};
+use js::jsapi::{JSContext, JS_ReadStructuredClone, JS_WriteStructuredClone, JS_ClearPendingException};
 use js::jsval::{JSVal, UndefinedValue};
 use js::rust::Cx;
 
@@ -154,16 +155,21 @@ impl DedicatedWorkerGlobalScope {
 }
 
 impl<'a> DedicatedWorkerGlobalScopeMethods for JSRef<'a, DedicatedWorkerGlobalScope> {
-    fn PostMessage(self, cx: *mut JSContext, message: JSVal) {
+    fn PostMessage(self, cx: *mut JSContext, message: JSVal) -> ErrorResult {
         let mut data = ptr::null_mut();
         let mut nbytes = 0;
-        unsafe {
+        let result = unsafe {
-            assert!(JS_WriteStructuredClone(cx, message, &mut data, &mut nbytes,
+            JS_WriteStructuredClone(cx, message, &mut data, &mut nbytes,
-                                            ptr::null(), ptr::null_mut()) != 0);
+                                    ptr::null(), ptr::null_mut())
+        };
+        if result == 0 {
+            unsafe { JS_ClearPendingException(cx); }
+            return Err(DataClone);
         }
 
         let ScriptChan(ref sender) = self.parent_sender;
         sender.send(WorkerPostMessage(self.worker, data, nbytes));
+        Ok(())
     }
 
     fn GetOnmessage(self) -> Option<EventHandlerNonNull> {

components/script/dom/domexception.rs

@@ -55,6 +55,7 @@ impl DOMErrorName {
             error::Network => NetworkError,
             error::Abort => AbortError,
             error::Timeout => TimeoutError,
+            error::DataClone => DataCloneError,
             error::FailureUnknown => fail!(),
         }
     }

components/script/dom/webidls/DedicatedWorkerGlobalScope.webidl

@@ -5,6 +5,7 @@
 // http://www.whatwg.org/html/#dedicatedworkerglobalscope
 [Global/*=Worker,DedicatedWorker*/]
 /*sealed*/ interface DedicatedWorkerGlobalScope : WorkerGlobalScope {
+  [Throws]
   void postMessage(any message/*, optional sequence<Transferable> transfer*/);
            attribute EventHandler onmessage;
 };

components/script/dom/webidls/Worker.webidl

@@ -14,6 +14,7 @@ interface AbstractWorker {
 interface Worker : EventTarget {
   //void terminate();
 
+  [Throws]
   void postMessage(any message/*, optional sequence<Transferable> transfer*/);
            attribute EventHandler onmessage;
 };

components/script/dom/worker.rs

@@ -6,7 +6,7 @@ use dom::bindings::codegen::Bindings::WorkerBinding;
 use dom::bindings::codegen::Bindings::WorkerBinding::WorkerMethods;
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
 use dom::bindings::codegen::InheritTypes::EventTargetCast;
-use dom::bindings::error::{Fallible, Syntax};
+use dom::bindings::error::{Fallible, Syntax, ErrorResult, DataClone};
 use dom::bindings::global::{GlobalRef, GlobalField};
 use dom::bindings::js::{JS, JSRef, Temporary};
 use dom::bindings::trace::JSTraceable;
@@ -20,7 +20,7 @@ use servo_util::str::DOMString;
 
 use js::glue::JS_STRUCTURED_CLONE_VERSION;
 use js::jsapi::{JSContext, JS_AddObjectRoot, JS_RemoveObjectRoot, JSTracer};
-use js::jsapi::{JS_ReadStructuredClone, JS_WriteStructuredClone};
+use js::jsapi::{JS_ReadStructuredClone, JS_WriteStructuredClone, JS_ClearPendingException};
 use js::jsval::{JSVal, UndefinedValue};
 use url::UrlParser;
 
@@ -133,17 +133,22 @@ impl Worker {
 }
 
 impl<'a> WorkerMethods for JSRef<'a, Worker> {
-    fn PostMessage(self, cx: *mut JSContext, message: JSVal) {
+    fn PostMessage(self, cx: *mut JSContext, message: JSVal) -> ErrorResult {
         let mut data = ptr::null_mut();
         let mut nbytes = 0;
-        unsafe {
+        let result = unsafe {
-            assert!(JS_WriteStructuredClone(cx, message, &mut data, &mut nbytes,
+            JS_WriteStructuredClone(cx, message, &mut data, &mut nbytes,
-                                            ptr::null(), ptr::null_mut()) != 0);
+                                    ptr::null(), ptr::null_mut())
+        };
+        if result == 0 {
+            unsafe { JS_ClearPendingException(cx); }
+            return Err(DataClone);
         }
 
         self.addref();
         let ScriptChan(ref sender) = self.sender;
         sender.send(DOMMessage(data, nbytes));
+        Ok(())
     }
 
     fn GetOnmessage(self) -> Option<EventHandlerNonNull> {

tests/wpt/metadata/workers/postMessage_DataCloneErr.htm.ini

@@ -1,6 +0,0 @@
-[postMessage_DataCloneErr.htm]
-  type: testharness
-  expected: TIMEOUT
-  [Test Description: Throw a DATA_CLONE_ERR exception when a host object (e.g. a DOM node) is used with postMessage.]
-    expected: NOTRUN
-