From 7c1412682e0c9de4ccd864c94d81579fcfbe9488 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 7 Mar 2024 14:24:47 +0000
Subject: [PATCH] Bug 1883796 - Deal with an assert that doesn't hold always.
 r=dshin

During an animation restyle, two links might share the same rules while
not sharing the same link-ness.

This is a temporary state, but let's deal with it correctly.

Differential Revision: https://phabricator.services.mozilla.com/D203891
---
 servo/components/style/sharing/mod.rs                 |  7 +------
 .../tests/css/selectors/link-sharing-crash.html       | 11 +++++++++++
 2 files changed, 12 insertions(+), 6 deletions(-)
 create mode 100644 testing/web-platform/tests/css/selectors/link-sharing-crash.html

diff --git a/servo/components/style/sharing/mod.rs b/servo/components/style/sharing/mod.rs
index eeea135c06c3..28592a02c5f2 100644
--- a/servo/components/style/sharing/mod.rs
+++ b/servo/components/style/sharing/mod.rs
@@ -908,12 +908,7 @@ impl<E: TElement> StyleSharingCache<E> {
             // RELEVANT_LINK_VISITED flag, so we can't share by rule node between visited and
             // unvisited styles. We don't check for visitedness and just refuse to share for links
             // entirely, so that visitedness doesn't affect timing.
-            debug_assert_eq!(
-                target.is_link(),
-                candidate.element.is_link(),
-                "Linkness mismatch"
-            );
-            if target.is_link() {
+            if target.is_link() || candidate.element.is_link() {
                 return None;
             }
 
diff --git a/testing/web-platform/tests/css/selectors/link-sharing-crash.html b/testing/web-platform/tests/css/selectors/link-sharing-crash.html
new file mode 100644
index 000000000000..3bcce92d49d6
--- /dev/null
+++ b/testing/web-platform/tests/css/selectors/link-sharing-crash.html
@@ -0,0 +1,11 @@
+<link rel="help" href="https://bugzil.la/1883796">
+<script>
+window.addEventListener("load", () => {
+  let a = document.createElementNS("http://www.w3.org/1999/xhtml", "a")
+  document.documentElement.appendChild(a)
+  document.documentElement.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "a"))
+  document.documentElement.scrollTo(-1132, 16)
+  document.documentElement.animate({"webkitTextStrokeWidth": ["197792984.89ex", "thin"]}, 2814)
+  a.setAttribute("href", "x")
+})
+</script>