From a604d605edf1813cc129409babb819d26db90824 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <ecoal95@gmail.com>
Date: Fri, 12 Feb 2016 01:51:36 +0100
Subject: [PATCH] style: Prevent a crash when push_applicable_declarations is
 called with a non eagerly-cascaded pseudo-element

This actually didn't happen, but this should be done sooner than later.
---
 components/style/selector_matching.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/components/style/selector_matching.rs b/components/style/selector_matching.rs
index be3ae5453fa..a6c93cebcbc 100644
--- a/components/style/selector_matching.rs
+++ b/components/style/selector_matching.rs
@@ -261,7 +261,12 @@ impl<Impl: SelectorImplExt> Stylist<Impl> {
                 "Style attributes do not apply to pseudo-elements");
 
         let map = match pseudo_element {
-            Some(ref pseudo) => self.pseudos_map.get(pseudo).unwrap(),
+            Some(ref pseudo) => match self.pseudos_map.get(pseudo) {
+                Some(map) => map,
+                // TODO(ecoal95): get non eagerly-cascaded pseudo-element rules here.
+                // Actually assume there are no rules applicable.
+                None => return true,
+            },
             None => &self.element_map,
         };