[2.0.0-beta5] Undefined array key "menu_link" in EntityReferencedDerivableContextDeriver::generateDefinitionsForReferencedEntityTypes()

Problem/Motivation

Currently after every cache clear I see the following PHP warning:

Warning: Undefined array key "menu_link" in Drupal\ui_patterns\Plugin\Derivative\EntityReferencedDerivableContextDeriver->generateDefinitionsForReferencedEntityTypes() (line 137)

But this only happens on (e.g. node) pages where the Data from a field source is used somewhere for a property of a component (the actual selected field source may be anything).

Steps to reproduce

• Create an entity with layout builder overrides enabled or configure a view mode with layout builder
• Add a component and use Data from a field source for any of its properties and map any of the available fields
• Open up the page where this layout is used
• Clear all caches
• Refresh the page where the layout is used and see the PHP warning

Proposed resolution

• Check for any potential underlying issue and/or adjust code of EntityReferencedDerivableContextDeriver::generateDefinitionsForReferencedEntityTypes() to be more defensive, so it may handle this case by e.g. ignoring that specific field by checking $this->entityFieldsMetadata[$entity_type_id]["field_storages"] for the existence of the field before using it

Remaining tasks

• Create issue fork an MR to fix this issue

User interface changes

n/a

API changes

n/a

Data model changes

n/a