Bug 1046647 - Part 4: Replace nsCxPusher in nsDocShell::AddState. r=bholley

content/base/public/nsContentUtils.h

@@ -172,11 +172,6 @@ class nsContentUtils
 public:
   static nsresult Init();
 
-  /**
-   * Get a JSContext from the document's scope object.
-   */
-  static JSContext* GetContextFromDocument(nsIDocument *aDocument);
-
   static bool     IsCallerChrome();
   static bool     ThreadsafeIsCallerChrome();
   static bool     IsCallerContentXBL();

content/base/src/nsContentUtils.cpp

@@ -1939,24 +1939,6 @@ nsContentUtils::InProlog(nsINode *aNode)
   return !root || doc->IndexOf(aNode) < doc->IndexOf(root);
 }
 
-JSContext *
-nsContentUtils::GetContextFromDocument(nsIDocument *aDocument)
-{
-  nsCOMPtr<nsIScriptGlobalObject> sgo =  do_QueryInterface(aDocument->GetScopeObject());
-  if (!sgo) {
-    // No script global, no context.
-    return nullptr;
-  }
-
-  nsIScriptContext *scx = sgo->GetContext();
-  if (!scx) {
-    // No context left in the scope...
-    return nullptr;
-  }
-
-  return scx->GetNativeContext();
-}
-
 //static
 void
 nsContentUtils::TraceSafeJSContext(JSTracer* aTrc)

docshell/base/nsDocShell.cpp

@@ -10772,19 +10772,7 @@ nsDocShell::AddState(JS::Handle<JS::Value> aData, const nsAString& aTitle,
         nsCOMPtr<nsIPrincipal> origPrincipal = origDocument->NodePrincipal();
 
         scContainer = new nsStructuredCloneContainer();
-        JSContext *cx = aCx;
-        nsCxPusher pusher;
-        if (!cx) {
-            cx = nsContentUtils::GetContextFromDocument(document);
-            pusher.Push(cx);
-        }
-        rv = scContainer->InitFromJSVal(aData, cx);
-
-        // If we're running in the document's context and the structured clone
-        // failed, clear the context's pending exception.  See bug 637116.
-        if (NS_FAILED(rv) && !aCx) {
-            JS_ClearPendingException(aCx);
-        }
+        rv = scContainer->InitFromJSVal(aData);
         NS_ENSURE_SUCCESS(rv, rv);
 
         nsCOMPtr<nsIDocument> newDocument = GetDocument();

dom/base/nsStructuredCloneContainer.cpp

@@ -8,15 +8,18 @@
 #include "nsStructuredCloneContainer.h"
 
 #include "nsCOMPtr.h"
-#include "nsIScriptContext.h"
+#include "nsIGlobalObject.h"
 #include "nsIVariant.h"
 #include "nsIXPConnect.h"
 #include "nsServiceManagerUtils.h"
 #include "nsContentUtils.h"
 #include "jsapi.h"
+#include "jsfriendapi.h"
 #include "js/StructuredClone.h"
+#include "xpcpublic.h"
 
 #include "mozilla/Base64.h"
+#include "mozilla/dom/ScriptSettings.h"
 
 using namespace mozilla;
 
@@ -39,22 +42,31 @@ nsStructuredCloneContainer::~nsStructuredCloneContainer()
 }
 
 nsresult
-nsStructuredCloneContainer::InitFromJSVal(JS::Handle<JS::Value> aData,
-                                          JSContext* aCx)
+nsStructuredCloneContainer::InitFromJSVal(JS::Handle<JS::Value> aData)
 {
   NS_ENSURE_STATE(!mData);
-  NS_ENSURE_ARG_POINTER(aCx);
-
-  // Make sure that we serialize in the right context.
-  MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
-  JS::Rooted<JS::Value> jsData(aCx, aData);
-  bool success = JS_WrapValue(aCx, &jsData);
-  NS_ENSURE_STATE(success);
 
   uint64_t* jsBytes = nullptr;
-  success = JS_WriteStructuredClone(aCx, jsData, &jsBytes, &mSize,
-                                    nullptr, nullptr,
-                                    JS::UndefinedHandleValue);
+  bool success = false;
+  if (aData.isPrimitive()) {
+    // |aData| is a primitive, so the structured clone algorithm won't run
+    // script and we can just use AutoJSAPI.
+    dom::AutoJSAPI jsapi;
+    jsapi.Init();
+    success = JS_WriteStructuredClone(jsapi.cx(), aData, &jsBytes, &mSize,
+                                      nullptr, nullptr,
+                                      JS::UndefinedHandleValue);
+  } else {
+    // |aData| is an object and the structured clone algorithm can run script as
+    // part of the "own" "deep clone" sub-steps, so we need an AutoEntryScript.
+    // http://www.whatwg.org/specs/web-apps/current-work/#internal-structured-cloning-algorithm
+    nsIGlobalObject* nativeGlobal =
+      xpc::GetNativeForGlobal(js::GetGlobalForObjectCrossCompartment(&aData.toObject()));
+    dom::AutoEntryScript aes(nativeGlobal);
+    success = JS_WriteStructuredClone(aes.cx(), aData, &jsBytes, &mSize,
+                                      nullptr, nullptr,
+                                      JS::UndefinedHandleValue);
+  }
   NS_ENSURE_STATE(success);
   NS_ENSURE_STATE(jsBytes);
 

dom/interfaces/base/nsIStructuredCloneContainer.idl

@@ -27,14 +27,14 @@ interface nsIDocument;
  * string containing a copy of the container's serialized data, using
  * getDataAsBase64.
  */
-[scriptable, uuid(c8852f01-4c05-47c3-acca-253a958f39f6)]
+[scriptable, uuid(8144021a-7f8a-483a-a0f1-ca02b761403f)]
 interface nsIStructuredCloneContainer : nsISupports
 {
   /**
    * Initialize this structured clone container so it contains a clone of the
    * given jsval.
    */
-  [noscript, implicit_jscontext]
+  [noscript]
   void initFromJSVal(in jsval aData);
 
   /**