From 4c68880cf90dbb1cef76bc860841f180ce9dcefb Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Thu, 12 Feb 2015 18:39:26 -0500
Subject: [PATCH] Bug 1132655.  Don't allow conversions from DOMString to const
 XPCOM string references, since it's meant to be an outparam only.  r=smaug

---
 dom/bindings/DOMString.h             | 5 +++++
 dom/html/HTMLTrackElement.h          | 2 +-
 dom/workers/ServiceWorkerClients.cpp | 2 +-
 dom/workers/WorkerScope.h            | 4 ++--
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/dom/bindings/DOMString.h b/dom/bindings/DOMString.h
index 5585e3dad4d..7169862425c 100644
--- a/dom/bindings/DOMString.h
+++ b/dom/bindings/DOMString.h
@@ -55,6 +55,11 @@ public:
     return AsAString();
   }
 
+  // It doesn't make any sense to convert a DOMString to a const nsString or
+  // nsAString reference; this class is meant for outparams only.
+  operator const nsString&() = delete;
+  operator const nsAString&() = delete;
+
   nsString& AsAString()
   {
     MOZ_ASSERT(!mStringBuffer, "We already have a stringbuffer?");
diff --git a/dom/html/HTMLTrackElement.h b/dom/html/HTMLTrackElement.h
index 4defd3b3f79..b0cdde8d7ef 100644
--- a/dom/html/HTMLTrackElement.h
+++ b/dom/html/HTMLTrackElement.h
@@ -97,7 +97,7 @@ public:
   {
     DOMString value;
     GetSrc(value);
-    aText = value;
+    value.ToString(aText);
   }
   virtual void SetItemValueText(const nsAString& aText) MOZ_OVERRIDE
   {
diff --git a/dom/workers/ServiceWorkerClients.cpp b/dom/workers/ServiceWorkerClients.cpp
index 0515075a7be..dfe7036ba19 100644
--- a/dom/workers/ServiceWorkerClients.cpp
+++ b/dom/workers/ServiceWorkerClients.cpp
@@ -250,7 +250,7 @@ ServiceWorkerClients::GetServiced(ErrorResult& aRv)
   MOZ_ASSERT(workerPrivate);
   workerPrivate->AssertIsOnWorkerThread();
 
-  DOMString scope;
+  nsString scope;
   mWorkerScope->GetScope(scope);
 
   nsRefPtr<Promise> promise = Promise::Create(mWorkerScope, aRv);
diff --git a/dom/workers/WorkerScope.h b/dom/workers/WorkerScope.h
index 84f6066f6d4..c903502a9cc 100644
--- a/dom/workers/WorkerScope.h
+++ b/dom/workers/WorkerScope.h
@@ -203,9 +203,9 @@ public:
                    JS::MutableHandle<JSObject*> aReflector) MOZ_OVERRIDE;
 
   void
-  GetScope(DOMString& aScope) const
+  GetScope(nsString& aScope) const
   {
-    aScope.AsAString() = mScope;
+    aScope = mScope;
   }
 
   void