Undefined array key error when viewing pages in admin panel

[xDehy]

Description of the Change

This pull request addresses an "Undefined array key" error that occurs when a post parent ID does not exist in the $children_pages array.

Changes Made:

• Added an isset() check before accessing the $children_pages array with the post parent ID.
• If the key does not exist, $siblings is set to an empty array to handle the case gracefully.

Closes #218

How to test the Change

Due to me not knowing exactly how this bug happened as it wasnt originally found by me, I can only assume. This bug was originally found by someone who edited a picture on a page and then dragged that page around to be a child page of another, which resulted in the Undefined array key error on the pages panel.

Changelog Entry

Fixed - issue where an "Undefined array key" error occurs when a post parent ID does not exist in the $children_pages array.

Credits

Props @xDehy

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[xDehy]

Just cleaned it up a little, realised I added extra, unnecessary lines of code

[peterwilsoncc]

Thanks @xDehy, this looks good to me.

I was able to reproduce the issue on an Admin > Pages list page containing only one page. This PR fixes the issue.

[peterwilsoncc]

Due to me not knowing exactly how this bug happened as it wasnt originally found by me, I can only assume.

Does the person who found the issue have a GitHub account so we can give them credit for discovery?

[xDehy]

Does the person who found the issue have a GitHub account so we can give them credit for discovery?

Nope, unfortunately not.