Navigation overlay close button may be displayed twice

[getdave]

What

When a navigation overlay template part uses a pattern (<!-- wp:pattern {"slug":"..."} /-->) that contained a close block, the close button was displayed twice - once for the close in the pattern and then a fallback. This PR fixes that.

Fixes #76567

Why

The fallback close button must only be shown when the overlay does not already contain a close block. The issue was that if the close block was within a Pattern the fallback detection logic failed to detect it thus leading to the duplication.

How

• Detect the close block in the rendered overlay HTML using WP_HTML_Tag_Processor
• Add block_core_navigation_overlay_html_has_close_block() helper
• Suppress the fallback close button when the overlay HTML contains the close button element

Why not check the block tree?

Pattern blocks are self-closing in the tree (<!-- wp:pattern {"slug":"..."} /-->); their inner content is not expanded there. A check like block_core_navigation_block_tree_has_block_type() never sees the close block inside patterns, so it always reports "no close block" and the fallback is incorrectly added.

Why check rendered HTML?

When the block renders, patterns are resolved and their content is output. The close button appears in the actual HTML. Detecting it there (e.g. via WP_HTML_Tag_Processor) correctly reflects what the user sees. It also accounts for edge cases such as hooks/filters adding close blocks...etc

Testing Instructions

1. Create a block theme with a navigation overlay template part
2. Inline close block: Add <!-- wp:navigation-overlay-close /--> directly in the template part. Verify one close button appears.
3. Pattern with close block: Create a pattern containing the overlay content (including <!-- wp:navigation-overlay-close /-->). Use <!-- wp:pattern {"slug":"theme/navigation-overlay"} /--> in the template part. Verify one close button appears (not two).
4. No close block: Use an overlay without the close block. Verify the fallback close button appears.

[github-actions]

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Co-authored-by: getdave <get_dave@git.wordpress.org>
Co-authored-by: scruffian <scruffian@git.wordpress.org>
Co-authored-by: benoitchantre <benoitchantre@git.wordpress.org>

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[getdave]

@benoitchantre would you be open to testing this fix to your reported bug?

You can test using Playground if that helps?

[Copilot]

Pull request overview

Fixes a Gutenberg navigation overlay rendering issue where the fallback close button could be output even when the overlay template part already renders a core/navigation-overlay-close block via a core/pattern, resulting in duplicate close buttons.

Changes:

• Switch close-button detection from block-tree inspection to rendered overlay HTML inspection (via WP_HTML_Tag_Processor) to correctly handle pattern expansion.
• Add block_core_navigation_overlay_html_has_close_block() helper for detecting the close button element in rendered overlay HTML.
• Add PHPUnit coverage for the new HTML-based detection, including the pattern-rendering scenario that triggered #76567.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
packages/block-library/src/navigation/index.php	Detects overlay close presence from rendered HTML (works with patterns) and suppresses fallback close button accordingly.
phpunit/blocks/class-wp-navigation-block-renderer-test.php	Adds unit tests for the new rendered-HTML close-button detection helper, including pattern output coverage.

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[github-actions]

Flaky tests detected in ca8ba3e.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/23214188635
📝 Reported issues:

• [Flaky Test] post title and content are editable and blocks can be inserted #76524 in /test/e2e/specs/editor/various/post-content-focus-mode.spec.js
• [Flaky Test] should move focus back to the Publish panel toggle button when canceling #76179 in /test/e2e/specs/editor/various/publish-panel.spec.js

[benoitchantre]

@benoitchantre would you be open to testing this fix to your reported bug?

You can test using Playground if that helps?

It works! Thank you for the fix.

Tested with the provided Playground link and a custom theme under development.

[scruffian]

Thanks for the fix. I can confirm it works with this test theme: WordPress/community-themes#263

[github-actions]

I just cherry-picked this PR to the wp/7.0 branch to get it included in the next release: f1ddd38