From 227e39d558455e8c427d85d0fffe98def0eb99d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <me@emiliocobos.me>
Date: Wed, 27 Apr 2016 22:39:49 +0200
Subject: [PATCH] style: Reset the per-pseudo-element maps when `update()` is
 called

This was causing panics in stylo.
---
 components/style/selector_matching.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/components/style/selector_matching.rs b/components/style/selector_matching.rs
index 8dcd139b7b4..72fdec38e43 100644
--- a/components/style/selector_matching.rs
+++ b/components/style/selector_matching.rs
@@ -171,6 +171,10 @@ impl<Impl: SelectorImplExt> Stylist<Impl> {
 
         self.element_map = PerPseudoElementSelectorMap::new();
         self.pseudos_map = HashMap::with_hasher(Default::default());
+        Impl::each_eagerly_cascaded_pseudo_element(|pseudo| {
+            self.pseudos_map.insert(pseudo, PerPseudoElementSelectorMap::new());
+        });
+
         self.non_eagerly_cascaded_pseudo_element_decls = HashMap::with_hasher(Default::default());
         self.rules_source_order = 0;
         self.state_deps.clear();