LibWeb: Bound the inline ancestor walks at the containing block

[kalenikaliaksandr]

The fragmented-inline-ancestor lookup and the piece-inset chain accumulation walked ancestor chains that terminate only at the first non-inline ancestor or the tree root. Both chains describe state owned by the current inline formatting context, so they must not leave its subtree: when the containing block is itself inline-level with flow inside (an inline list-item root), the old walks could cross into the enclosing context's boxes. Both walks now stop at the containing block.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 33d51bd3-76ae-4d66-a58c-9bfce9ac387b

📥 Commits

Reviewing files that changed from the base of the PR and between 9b13b59 and e7404c3.

📒 Files selected for processing (1)

• Libraries/LibWeb/Rust/src/layout/inline_formatting_context.rs

---

📝 Walkthrough

Walkthrough

The inline formatting context now stops ancestor traversal at its containing block. This applies to fragmented inline ancestor lookup and relative inset accumulation.

Changes

Inline formatting context boundaries

Layer / File(s)	Summary
Containing-block traversal boundaries Libraries/LibWeb/Rust/src/layout/inline_formatting_context.rs	nearest_fragmented_inline_ancestor stops at self.containing_block. Relative inset accumulation uses the same boundary instead of an invalid node.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• LadybirdBrowser/ladybird#10968: Refines the same fragmented-inline ancestor traversal and relative-inset logic.
• LadybirdBrowser/ladybird#10971: Modifies inline formatting-context traversal and layout-run handling.
• LadybirdBrowser/ladybird#11015: Modifies inline-ancestor traversal and containing-block boundaries.

Suggested reviewers: shannonbooth

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description check	✅ Passed	The description directly explains the changes to bound both inline ancestor walks at the containing block.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}