Make CSSRule always keep a pointer to its parent stylesheet

even when the parentStylesheet IDL attribute returns null.

1 files changed, 5 insertions, 4 deletions

diff --git a/components/script/dom/cssnamespacerule.rs b/components/script/dom/cssnamespacerule.rs
index 4e93eea2e1f..5f451d3b798 100644
--- a/components/script/dom/cssnamespacerule.rs
+++ b/components/script/dom/cssnamespacerule.rs
@@ -23,17 +23,18 @@ pub struct CSSNamespaceRule {
 }
 
 impl CSSNamespaceRule {
-    fn new_inherited(parent: Option<&CSSStyleSheet>, namespacerule: Arc<RwLock<NamespaceRule>>) -> CSSNamespaceRule {
+    fn new_inherited(parent_stylesheet: &CSSStyleSheet, namespacerule: Arc<RwLock<NamespaceRule>>)
+                     -> CSSNamespaceRule {
         CSSNamespaceRule {
-            cssrule: CSSRule::new_inherited(parent),
+            cssrule: CSSRule::new_inherited(parent_stylesheet),
             namespacerule: namespacerule,
         }
     }
 
     #[allow(unrooted_must_root)]
-    pub fn new(window: &Window, parent: Option<&CSSStyleSheet>,
+    pub fn new(window: &Window, parent_stylesheet: &CSSStyleSheet,
                namespacerule: Arc<RwLock<NamespaceRule>>) -> Root<CSSNamespaceRule> {
-        reflect_dom_object(box CSSNamespaceRule::new_inherited(parent, namespacerule),
+        reflect_dom_object(box CSSNamespaceRule::new_inherited(parent_stylesheet, namespacerule),
                            window,
                            CSSNamespaceRuleBinding::Wrap)
     }