Problem/Motivation
The bundle filter which was introduced in the entity parameter converter doesn't check if an entity exists before calling methods on it, resulting in a fatal error when a non-existing entity ID is passed in:
Error: Call to a member function bundle() on null in core/lib/Drupal/Core/ParamConverter/EntityConverter.php:145
Steps to reproduce
Pass a non-existing entity ID and a bundle filter to EntityConverter::convert().
Proposed resolution
Don't call methods on nullable objects without checking if they are NULL.
Remaining tasks
Review and commit.
User interface changes
None.
API changes
None.
Data model changes
None.
Release notes snippet
N/A
