@Query returning Couldn't find PersistentEntity when querying one column with null value

[aquilesb]

Hi,

I have upgraded spring-boot from 2.5.10 to 2.6.4 and I noticed one behavior has changed and stopped working.
When I try to load using the @Query annotation only one column from the query and return it inside an Optional, it throws the Couldn't find PersistentEntity Exception when the value of the column is null in the DB. If the column has a value, it works as before.

In version 2.5.10, it was returning an empty Optional. If I try to return the Entity inside the optional, it works as before.

I have created this repo to where I reproduce the behavior.

[schauder]

Duplicate of #1167

Fixed by 63f2331

The fix will be included in the 2.4.0-M4 release.