Warning: array_flip(): Can only flip STRING and INTEGER values! in Drupal\Core\Entity\ContentEntityStorageBase->loadMultipleRevisions() (line 666 of core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php).

Problem/Motivation

Hi, After updating Drupal core from 9.2.10 to 9.3.0, i have getting two warnings on node entity revision page. Note that content types have moderation state enabled.

Warning: array_flip(): Can only flip STRING and INTEGER values! in Drupal\Core\Entity\ContentEntityStorageBase->loadMultipleRevisions() (line 666 of core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php).

Warning: Illegal offset type in Drupal\Core\Entity\ContentEntityStorageBase->loadRevision() (line 635 of core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php).

Steps to reproduce

Update Drupal core from 9.2.10 to 9.3.0.
Open any node revision page, Example: /node/5261/revisions/124171/view

Proposed resolution

Warning should not be thrown and code should handle any null value if passed