wp_get_post_parent_id() does not default to global $post

[danielpost]

https://core.trac.wordpress.org/browser/tags/5.2.4/src/wp-includes/post.php#L6595

Because wp_get_post_parent_id() does not declare a default value for the $post parameter, calling it without explicitly passing the $post parameter results in an error. This means that it will never default to the global $post. I believe the fix here is to declare $post = null in the function declaration and specify in the PHPDoc that this parameter is optional, similar to how other functions handle this.

[danielpost]

Adds test

[davidbaumwald]

This doesn't need a full dev-note, but it should get a small call-out in the miscellaneous changes note in 5.4.

[birgire]

The test in 48358.1.diff​ might need the annotation @ticket 48358. I also wonder if the function's doc would need the @since annotation after the signature change.

[danielpost]

I'm happy to make those changes if the consensus is that they're necessary—I don't have enough experience with core contributing to make that call myself.

[davidbaumwald]

With 5.4 Beta 3 approaching and the Beta period reserved for bugs introduced during the cycle, this is being moved to Future Release. If any maintainer or committer feels this should be included or wishes to assume ownership during a specific cycle, feel free to update the milestone accordingly.

[audrasjb]

The patch doesn't apply against trunk anymore.

[audrasjb]

Posts, Post Types: Default wp_get_post_parent_id() to global $post

[audrasjb]

Refreshed in 48358.2.diff. I also added the ticket number in the provided tests.

Trac ticket: https://core.trac.wordpress.org/ticket/48358

The failing test looks like an unrelated issue.

@audrasjb It's a remote request to wp.org that has timed out. There's a ticket open to mock each of these HTTP remote requests https://core.trac.wordpress.org/ticket/54420. Adding this test to that ticket's list.

But you're right. This failing test is not associated with this PR.

[hellofromTonya]

​PR 1898 is ready for commit.

Tests are passing now 😉

[peterwilsoncc]

In 48358.3.diff​:

• Functional code in PR as approved earlier
• @covers and @since documentation added
• @param ... $post description modified for consistency with the same use case elsewhere in core

I pushed the latter two items to @audrasjb's branch, presuming the tests pass I will commit momentarily.

[peterwilsoncc]

In 52194:

Posts, Post Types: Use global post as the default for wp_get_post_parent_id().

Convert the $post parameter of wp_get_post_parent_id() to optional, defaulting to the current global post object when called within the loop.

Props danielpost, davidbaumwald, SergeyBiryukov, birgire, audrasjb, hellofromTonya, TimothyBlynJacobs.
Fixes #48358.

https://core.trac.wordpress.org/changeset/52194

[audrasjb]

Dev note published: ​https://make.wordpress.org/core/2022/01/04/miscellaneous-core-changes-in-wordpress-5-9/