Bug 1160447 - xhr internal code exposure. r=jst, a=sylvestre

dom/base/nsXMLHttpRequest.cpp

@@ -303,6 +303,7 @@ nsXMLHttpRequest::nsXMLHttpRequest()
     mUploadTransferred(0), mUploadTotal(0), mUploadComplete(true),
     mProgressSinceLastProgressEvent(false),
     mRequestSentTime(0), mTimeoutMilliseconds(0),
+    mErrorStatus(NS_OK),
     mErrorLoad(false), mWaitingForOnStopRequest(false),
     mProgressTimerIsActive(false),
     mIsHtml(false),
@@ -1168,6 +1169,15 @@ nsXMLHttpRequest::Status()
   return status;
 }
 
+uint32_t
+nsXMLHttpRequest::InternalErrorCode() {
+  if (IsDeniedCrossSiteRequest()) {
+    return 0;
+  }
+
+  return (uint32_t)mErrorStatus;
+}
+
 IMPL_CSTRING_GETTER(GetStatusText)
 void
 nsXMLHttpRequest::GetStatusText(nsCString& aStatusText)
@@ -2219,6 +2229,8 @@ nsXMLHttpRequest::OnStopRequest(nsIRequest *request, nsISupports *ctxt, nsresult
     return NS_OK;
   }
 
+  mErrorStatus = status;
+
   mWaitingForOnStopRequest = false;
 
   if (mRequestObserver) {

dom/base/nsXMLHttpRequest.h

@@ -499,6 +499,7 @@ public:
   // response
   void GetResponseURL(nsAString& aUrl);
   uint32_t Status();
+  uint32_t InternalErrorCode();
   void GetStatusText(nsCString& aStatusText);
   void GetResponseHeader(const nsACString& aHeader, nsACString& aResult,
                          ErrorResult& aRv);
@@ -751,6 +752,7 @@ protected:
   nsCOMPtr<nsITimer> mTimeoutTimer;
   void StartTimeoutTimer();
   void HandleTimeoutCallback();
+  nsresult mErrorStatus;
 
   bool mErrorLoad;
   bool mWaitingForOnStopRequest;

dom/webidl/XMLHttpRequest.webidl

@@ -112,6 +112,8 @@ interface XMLHttpRequest : XMLHttpRequestEventTarget {
   [Throws=Workers]
   readonly attribute unsigned short status;
 
+  readonly attribute unsigned long internalErrorCode;
+
   readonly attribute ByteString statusText;
   [Throws]
   ByteString? getResponseHeader(ByteString header);

dom/workers/XMLHttpRequest.h

@@ -199,6 +199,11 @@ public:
     return mStateData.mStatus;
   }
 
+  uint32_t
+  InternalErrorCode() const {
+    return 0;
+  }
+
   void
   GetStatusText(nsACString& aStatusText) const
   {