HHH-16908 Mapping error when using unowned associations as identifiers

hibernate-core/src/main/java/org/hibernate/boot/model/internal/OneToOneSecondPass.java

@@ -208,7 +208,7 @@ public class OneToOneSecondPass implements SecondPass {
 		final KeyValue targetEntityIdentifier = targetEntity.getIdentifier();
 		boolean referenceToPrimaryKey = mappedBy == null
 				|| targetEntityIdentifier instanceof Component
-						&& !( (Component) targetEntityIdentifier ).hasProperty( mappedBy );
+						&& ( (Component) targetEntityIdentifier ).hasProperty( mappedBy );
 		oneToOne.setReferenceToPrimaryKey( referenceToPrimaryKey );
 
 		final String propertyRef = oneToOne.getReferencedPropertyName();

hibernate-core/src/main/java/org/hibernate/boot/model/internal/ToOneBinder.java

@@ -92,6 +92,13 @@ public class ToOneBinder {
 			);
 		}
 
+		if ( joinColumns.hasMappedBy() && isIdentifier( propertyHolder, propertyBinder, isIdentifierMapper ) ) {
+			throw new AnnotationException(
+					"Property '" + getPath( propertyHolder, inferredData )
+							+ "' is the inverse side of a '@ManyToOne' association and cannot be used as identifier"
+			);
+		}
+
 		final Cascade hibernateCascade = property.getAnnotation( Cascade.class );
 		final NotFound notFound = property.getAnnotation( NotFound.class );
 		final NotFoundAction notFoundAction = notFound == null ? null : notFound.action();
@@ -121,6 +128,13 @@ public class ToOneBinder {
 		);
 	}
 
+	private static boolean isIdentifier(
+			PropertyHolder propertyHolder,
+			PropertyBinder propertyBinder,
+			boolean isIdentifierMapper) {
+		return propertyBinder.isId() || propertyHolder.isOrWithinEmbeddedId() || propertyHolder.isInIdClass() || isIdentifierMapper;
+	}
+
 	private static boolean isMandatory(boolean optional, XProperty property, NotFoundAction notFoundAction) {
 		// @MapsId means the columns belong to the pk;
 		// A @MapsId association (obviously) must be non-null when the entity is first persisted.
@@ -405,6 +419,13 @@ public class ToOneBinder {
 			);
 		}
 
+		if ( joinColumns.hasMappedBy() && isIdentifier( propertyHolder, propertyBinder, isIdentifierMapper ) ) {
+			throw new AnnotationException(
+					"Property '" + getPath( propertyHolder, inferredData )
+							+ "' is the inverse side of a '@OneToOne' association and cannot be used as identifier"
+			);
+		}
+
 		//FIXME support a proper PKJCs
 		final boolean trueOneToOne = property.isAnnotationPresent( PrimaryKeyJoinColumn.class )
 				|| property.isAnnotationPresent( PrimaryKeyJoinColumns.class );