[layout] Fix null-deref when attempting to mark a scrollbar for layout

Custom scrollbar parts are weird in that they don't have a parent. We'd unconditionally attempt to access their containing block causing a null-deref. Fixed: 355016913 Change-Id: I9c32cf7efc00543021111bb3eaa1e8488052264f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5760674 Reviewed-by: David Grogan <[email protected]> Commit-Queue: Ian Kilpatrick <[email protected]> Cr-Commit-Position: refs/heads/main@{#1337141}
web-platform-tests · Aug 5, 2024 · 84d708b · 84d708b
1 parent 2f9e207
commit 84d708b
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/css/css-scrollbars/invalid-needs-layout-crash.html b/css/css-scrollbars/invalid-needs-layout-crash.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<style>
+#target::-webkit-scrollbar { position: absolute; }
+#target.crash::-webkit-scrollbar { right: 0 }
+</style>
+<div id="target" style="width: 100px; height: 100px; overflow: auto;"><div style="height: 200px;"></div></div>
+<script>
+document.body.offsetTop;
+document.getElementById('target').classList.add('crash');
+</script>