From 28d9c652931e9964a4d2d3bdfcc0a4847050e1c9 Mon Sep 17 00:00:00 2001
From: Marco Belladelli <marco@hibernate.org>
Date: Wed, 19 Jul 2023 14:52:16 +0200
Subject: [PATCH] HHH-16908 Mapping error when using unowned associations as
 identifiers

---
 .../model/internal/OneToOneSecondPass.java    |  2 +-
 .../boot/model/internal/ToOneBinder.java      | 25 +++++++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/boot/model/internal/OneToOneSecondPass.java b/hibernate-core/src/main/java/org/hibernate/boot/model/internal/OneToOneSecondPass.java
index 8f92b91a1f..e90383c396 100644
--- a/hibernate-core/src/main/java/org/hibernate/boot/model/internal/OneToOneSecondPass.java
+++ b/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();
diff --git a/hibernate-core/src/main/java/org/hibernate/boot/model/internal/ToOneBinder.java b/hibernate-core/src/main/java/org/hibernate/boot/model/internal/ToOneBinder.java
index 757ddf9565..991831d986 100644
--- a/hibernate-core/src/main/java/org/hibernate/boot/model/internal/ToOneBinder.java
+++ b/hibernate-core/src/main/java/org/hibernate/boot/model/internal/ToOneBinder.java
@@ -90,11 +90,18 @@ public class ToOneBinder {
 		if ( property.isAnnotationPresent( Column.class )
 				|| property.isAnnotationPresent( Columns.class ) ) {
 			throw new AnnotationException(
-					"Property '"+ getPath( propertyHolder, inferredData )
+					"Property '" + getPath( propertyHolder, inferredData )
 							+ "' is a '@ManyToOne' association and may not use '@Column' to specify column mappings (use '@JoinColumn' instead)"
 			);
 		}
 
+		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();
@@ -124,6 +131,13 @@ 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.
@@ -421,12 +435,19 @@ public class ToOneBinder {
 		if ( property.isAnnotationPresent( Column.class )
 				|| property.isAnnotationPresent( Columns.class ) ) {
 			throw new AnnotationException(
-					"Property '"+ getPath( propertyHolder, inferredData )
+					"Property '" + getPath( propertyHolder, inferredData )
 							+ "' is a '@OneToOne' association and may not use '@Column' to specify column mappings"
 							+ " (use '@PrimaryKeyJoinColumn' instead)"
 			);
 		}
 
+		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 );