--- a/dom/base/nsAttrInfo.h
+++ b/dom/base/nsAttrInfo.h
@@ -34,11 +34,13 @@ struct nsAttrInfo
   nsAttrInfo(const nsAttrInfo& aOther)
     : mName(aOther.mName)
     , mValue(aOther.mValue)
   {
   }
 
   const nsAttrName* mName;
   const nsAttrValue* mValue;
+
+  explicit operator bool() const { return mName != nullptr; }
 };
 
 #endif

--- a/dom/svg/SVGUseElement.cpp
+++ b/dom/svg/SVGUseElement.cpp
@@ -294,27 +294,28 @@ SVGUseElement::CreateAnonymousContent()
                                             nsIDOMNode::ELEMENT_NODE);
 
     nsCOMPtr<nsIContent> svgNode;
     NS_NewSVGSVGElement(getter_AddRefs(svgNode), nodeInfo.forget(),
                         NOT_FROM_PARSER);
 
     if (!svgNode)
       return nullptr;
-    
+
     // copy attributes
-    const nsAttrName* name;
+    nsAttrInfo info;
     uint32_t i;
-    for (i = 0; (name = newcontent->GetAttrNameAt(i)); i++) {
+    for (i = 0; (info = newcontent->GetAttrInfoAt(i)); i++) {
       nsAutoString value;
-      int32_t nsID = name->NamespaceID();
-      nsIAtom* lname = name->LocalName();
+      int32_t nsID = info.mName->NamespaceID();
+      nsIAtom* lname = info.mName->LocalName();
 
-      newcontent->GetAttr(nsID, lname, value);
-      svgNode->SetAttr(nsID, lname, name->GetPrefix(), value, false);
+      info.mValue->ToString(value);
+
+      svgNode->SetAttr(nsID, lname, info.mName->GetPrefix(), value, false);
     }
 
     // move the children over
     uint32_t num = newcontent->GetChildCount();
     for (i = 0; i < num; i++) {
       nsCOMPtr<nsIContent> child = newcontent->GetFirstChild();
       newcontent->RemoveChildAt(0, false);
       svgNode->InsertChildAt(child, i, true);