loadUnchanged() returns an in-memory-modified entity when hook_entity_preload() swaps in a non-default revision

Problem/Motivation

ContentEntityStorageBase::loadUnchanged() should return an entity's persisted state, discarding unsaved in-memory changes. But it only calls parent::resetCache(), which clears the entity static cache and not the static revision cache.

When a module returns a non-default revision from hook_entity_preload() (as Workspaces does), the reload goes through loadMultipleRevisions() -> getFromStaticRevisionCache(), which still holds the same object that might have been changed in the current request.

Steps to reproduce

1. Create an entity (default revision).
2. Create a second, non-default (pending) revision.
3. Make that pending revision the result of hook_entity_preload() for the entity ID.
4. load the entity (gets the pending revision), then modify a field in memory without saving.
5. Call loadUnchanged() on the same ID.

Proposed resolution

In ContentEntityStorageBase::loadUnchanged(), after parent::resetCache($ids), also invalidate the static revision cache for statically-cacheable revisionable entity types (via the {type}:{id}:revisions memory cache tags). This forces the subsequent preload/reload to fetch fresh revisions from the persistent cache or storage, without deleting the persistent cache that loadUnchanged()'s fast path relies on.

Remaining tasks

Review.

User interface changes

Nope.

Introduced terminology

N/A

API changes

Nope.

Data model changes

Nope.

Release notes snippet

N/A