[text-decorations] Fix first-line when there's a paint layer

kojiishi · chromium-wpt-export-bot · commit 3410c1965134 · 2025-05-14T11:46:48.000-07:00
An inline box with a paint layer uses `ScopedInlineBoxAncestors` to synchronize decoration boxes instead of `ScopedInlineItem`. This code path doesn't need to save decorating boxes, and thus `saved_decorating_boxes_` is `nullptr`. Fixes for `::first-line` in crrev.com/c/4545917 and crrev.com/c/4493872 assumed `saved_decorating_boxes_` exists. To reduce the complexity, this patch changes `saved_decorating_boxes_` to be required, and let `ScopedInlineBoxAncestors` to provide it. Fixed: 406109047 Change-Id: I0683a666250867f8c4c9fa9271c0d300e38cabf5 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6546415 Reviewed-by: Philip Rogers <pdr@chromium.org> Auto-Submit: Koji Ishii <kojii@chromium.org> Commit-Queue: Philip Rogers <pdr@chromium.org> Cr-Commit-Position: refs/heads/main@{#1460175}
diff --git a/css/css-text-decor/crashtests/text-decoration-first-line-layer-crash.html b/css/css-text-decor/crashtests/text-decoration-first-line-layer-crash.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<link rel="help" href="http://crbug.com/406109047">
+<style type="text/css">
+.c2 {
+  float: right;
+  text-decoration: overline;
+}
+
+.c2::first-letter {
+  vertical-align: super;
+  opacity: 0.1;
+}
+
+.c2::first-line {
+  text-decoration: overline;
+}
+</style>
+<script>
+let element = document.createElement('q');
+element.setAttribute('class', 'c2');
+document.documentElement.appendChild(element);
+let text_node = document.createTextNode('appxgrxebpwykansiejjshzsznwgqyelwkrlpjsmtdhhfnywteevgcricqxp');
+window.requestAnimationFrame(function() {
+  element.appendChild(text_node);
+});
+</script>
