[salvatorecorsi]

Query Loop can throw a PHP TypeError when its sticky-post setting is exclude and the stored sticky_posts option is a string or is missing. A nonempty string also reaches post__in unchanged in only mode.

Normalize a non-array option to an empty local list before constructing the query. Valid arrays retain their existing behavior; only still uses the existing array( 0 ) sentinel to return no posts. The stored option is not modified. This follows the defensive handling already used by other sticky-post readers.

Trac ticket: https://core.trac.wordpress.org/ticket/60276

To reproduce on a disposable test site, set sticky_posts to an empty string, insert a Query Loop with inherited query disabled, select Sticky Posts → Exclude, and render or save the template. Before this change, array_merge() receives a string; afterwards the query runs without treating the invalid value as post IDs. The ticket's original corrupted value was observed on an old WordPress.com site; its source was not established.

Validation on Windows, PHP 8.3.28, PHPUnit 9.6.38, using the isolated native test database:

• Added 15 real-option/WP_Block/WP_Query cases covering three sticky modes, empty/nonempty/numeric strings, a missing option and an empty-array control. They also verify explicit exclusions and that the option is not rewritten. Against unchanged runtime: 4 TypeErrors and 2 assertion failures (15 tests, 29 assertions); with the fix: 15 tests, 45 assertions passed.
• scripts/test-php.ps1 -Repository wordpress-develop -Checkout C:/Users/salva/.wp-fix/worktrees/wordpress-develop-60276 -Filter '^Tests_Blocks_wpBlock::': 64 tests, 221 assertions passed, including the existing valid-array sticky-post cases.
• WPCS and PHP compatibility checks on both changed PHP files, PHP syntax checks, production-file PHPStan (0 errors), and git diff --check: passed.
• Full npm run build after the runtime fix: passed. The built and source wp-includes/blocks.php copies have identical SHA-256 hashes. Existing Node deprecation and webpack asset-size/performance warnings remain nonfatal.

A preliminary broader filter (Tests_Blocks_wpBlock) also matched unrelated metadata-registry classes: 241 tests / 531 assertions with one Windows path-separator failure. That exact registry test fails identically against the frozen unchanged runtime (1 test / 2 assertions). It is retained as a known baseline limitation. PHPUnit also reports its existing deprecated XML-schema warning. No full PHPUnit, multisite or Docker E2E pass is claimed.

Use of AI Tools

AI assistance: Yes. OpenAI Codex investigated the ticket, authored the implementation and regression tests, and ran the recorded automated validation. A separate Codex agent reviewed the source, tests and results. The owner has not performed a human review; maintainer review is needed for acceptance into WordPress.

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