[wp-trac] [WordPress Trac] #64670: WP_REST_Posts_Controller::update_item() not passing parent to wp_unique_post_slug() for draft child

[WordPress Trac]

#64670: WP_REST_Posts_Controller::update_item() not passing parent to
wp_unique_post_slug() for draft child
-------------------------------+-------------------------------------------
 Reporter:  esaner             |       Owner:  (none)
     Type:  defect (bug)       |      Status:  new
 Priority:  normal             |   Milestone:  Awaiting Review
Component:  REST API           |     Version:  6.9.1
 Severity:  normal             |  Resolution:
 Keywords:  has-patch needs-   |     Focuses:  ui, administration, rest-api
  testing                      |
-------------------------------+-------------------------------------------

Comment (by ekamran):

 == Test Report ==

 Patch tested: https://github.com/WordPress/wordpress-develop/pull/10973

 === Environment ===

 * Reported version: 6.9.1
 * Tested version: 7.1-alpha-62161-src
 * PHP: 8.3.31
 * Environment: wordpress-develop local Docker environment
 * Test method: WP-CLI automated reproduction using `rest_do_request()`
 * OS: macOS

 === Reproduction ===

 I was able to confirm that the reported issue is still reproducible on
 current trunk.

 The test setup:

 * Set up a published top-level page with slug `slug`.
 * Set up a published parent page with slug `parent`.
 * Set up a draft child page under the parent.
 * Sent a REST API update request to the draft child page with `slug=slug`,
 without sending a `parent` value.

 Clean trunk result:

 {{{
 {
     "first_id": 12,
     "parent_id": 13,
     "child_id": 14,
     "response_status": 200,
     "response_slug": "slug-2",
     "stored_child_slug": "slug-2",
     "stored_child_parent": 13,
     "child_permalink": "http://localhost:8889/?page_id=14",
     "top_slug_permalink": "http://localhost:8889/slug/"
 }
 }}}

 This confirms the bug: the draft child page remains under parent `13`, but
 the REST update changes the requested slug from `slug` to `slug-2`,
 because the uniqueness check behaves as if the parent were `0`.

 === Patch Result ===

 After applying PR #10973 locally and running the same automated
 reproduction, the draft child page keeps the requested slug `slug` while
 preserving its parent:

 {{{
 {
     "first_id": 16,
     "parent_id": 17,
     "child_id": 18,
     "response_status": 200,
     "response_slug": "slug",
     "stored_child_slug": "slug",
     "stored_child_parent": 17,
     "child_permalink": "http://localhost:8889/?page_id=18",
     "top_slug_permalink": "http://localhost:8889/slug/"
 }
 }}}

 === Tests ===

 I also ran the related REST pages controller PHPUnit tests with the patch
 applied:

 {{{
 npm run test:php -- --filter WP_Test_REST_Pages_Controller

 OK (34 tests, 142 assertions)
 }}}

 === Notes ===

 The patch fixes the REST API draft child page slug behavior by falling
 back to the existing post parent when the REST update request does not
 include `parent`.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/64670#comment:3>
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