Bug 819475 - Make document.domain non-nullable; r=bz

Make document.domain non-nullable, to conform to the HTML spec.

MozReview-Commit-ID: B1YuQekBgZD

--HG--
extra : rebase_source : 00999e16549e62c783f06f61c62000ab7677cf1d

dom/html/nsHTMLDocument.cpp

@@ -890,7 +890,7 @@ nsHTMLDocument::GetDomain(nsAString& aDomain)
   nsCOMPtr<nsIURI> uri = GetDomainURI();
 
   if (!uri) {
-    SetDOMStringToNull(aDomain);
+    aDomain.Truncate();
     return;
   }
 
@@ -900,8 +900,8 @@ nsHTMLDocument::GetDomain(nsAString& aDomain)
     CopyUTF8toUTF16(hostName, aDomain);
   } else {
     // If we can't get the host from the URI (e.g. about:, javascript:,
-    // etc), just return an null string.
-    SetDOMStringToNull(aDomain);
+    // etc), just return an empty string.
+    aDomain.Truncate();
   }
 }
 

dom/webidl/HTMLDocument.webidl

@@ -7,7 +7,7 @@
 [OverrideBuiltins]
 interface HTMLDocument : Document {
            [SetterThrows]
-           attribute DOMString? domain;
+           attribute DOMString domain;
            [Throws]
            attribute DOMString cookie;
   // DOM tree accessors