From 93c39b073072bed1c2de3f31ef3d79832a3d49bd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 31 May 2017 17:20:31 +0200
Subject: [PATCH] Bug 1369187: style: Assert that if we find an eager,
 element-backed pseudo, it's ::before or ::after. r=bholley

This holds because ::first-line and ::first-letter are not element-backed.

MozReview-Commit-ID: 67FU15pCLqW
---
 components/style/matching.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/components/style/matching.rs b/components/style/matching.rs
index 6dc335de1dc..eb88914f8ed 100644
--- a/components/style/matching.rs
+++ b/components/style/matching.rs
@@ -357,6 +357,7 @@ trait PrivateMatchMethods: TElement {
             // below like a lazy pseudo.
             let only_default_rules = context.shared.traversal_flags.for_default_styles();
             if pseudo.is_eager() && !only_default_rules {
+                debug_assert!(pseudo.is_before_or_after());
                 let parent = self.parent_element().unwrap();
                 if !parent.may_have_animations() ||
                    primary_style.rules.get_animation_rules().is_empty() {