HHH-15767 put unique constraints where they belong on optional @OneToOne associations

this was a bug that allowed people to use @OneToOne as a regular @ManyToOne
and ... people did ... as evidenced by all these bogus tests I just fixed

this is in principle a breaking change because it breaks code that was broken

hibernate-core/src/main/java/org/hibernate/cfg/OneToOneSecondPass.java

@@ -241,36 +241,32 @@ public class OneToOneSecondPass implements SecondPass {
 		// if not, then we need to create a many to one and formula
 		// but actually, since entities linked by a one to one need
 		// to share the same composite id class, this cannot happen
-		boolean rightOrder = true;
+//		boolean rightOrder = true;
-
+//
-		if ( rightOrder ) {
+//		if ( rightOrder ) {
-			final ToOneFkSecondPass secondPass = new ToOneFkSecondPass(
+		final ToOneFkSecondPass secondPass = new ToOneFkSecondPass(
-					oneToOne,
+				oneToOne,
-					joinColumns,
+				joinColumns,
-					!optional, //cannot have nullable and unique on certain DBs
+				true,
-					propertyHolder.getPersistentClass(),
+				propertyHolder.getPersistentClass(),
-					qualify( propertyHolder.getPath(), propertyName),
+				qualify( propertyHolder.getPath(), propertyName),
-					buildingContext
+				buildingContext
-			);
+		);
-			secondPass.doSecondPass(persistentClasses);
+		secondPass.doSecondPass(persistentClasses);
-			//no column associated since it's a one to one
+		//no column associated since it's a one to one
-			propertyHolder.addProperty( property, inferredData.getDeclaringClass() );
+		propertyHolder.addProperty( property, inferredData.getDeclaringClass() );
-		}
+//		}
 //		else {
 			// this is a @ManyToOne with Formula
 //		}
 	}
 
 	/**
-	 * Builds the <code>Join</code> instance for the mapped by side of a <i>OneToOne</i> association using
+	 * Builds the {@link Join} instance for the unowned side
-	 * a join table.
+	 * of a {@code OneToOne} association using a join table.
-	 * <p>
+	 * From the {@code mappedBy} side we should not create
-	 * Note:<br/>
+	 * neither the PK, nor the FK, this is all handled from
-	 * <ul>
+	 * the owning side.
-	 * <li>From the mappedBy side we should not create the PK nor the FK, this is handled from the other side.</li>
-	 * <li>This method is a dirty dupe of EntityBinder.bindSecondaryTable</li>.
-	 * </ul>
-	 * </p>
 	 */
 	private Join buildJoinFromMappedBySide(PersistentClass persistentClass, Property otherSideProperty, Join originalJoin) {
 		Join join = new Join();

hibernate-core/src/main/java/org/hibernate/cfg/ToOneBinder.java

@@ -179,7 +179,7 @@ public class ToOneBinder {
 		final FkSecondPass secondPass = new ToOneFkSecondPass(
 				value,
 				joinColumns,
-				!optional && unique, //cannot have nullable and unique on certain DBs like Derby
+				unique,
 				propertyHolder.getPersistentClass(),
 				fullPath,
 				context

hibernate-core/src/test/java/org/hibernate/orm/test/embeddable/MappedByEmbeddableTest.java

@@ -61,15 +61,13 @@ public class MappedByEmbeddableTest extends BaseCoreFunctionalTestCase {
 			Contained contained2 = embed2.getContained();
 
 			// switch associations: 1:1 2:2 -> 1:2 2:1
+			contained1.setContaining( null );
+			embed2.setContained( null );
+			session.flush();
 			embed1.setContained( contained2 );
 			contained2.setContaining( containing1 );
 			embed2.setContained( contained1 );
 			contained1.setContaining( containing2 );
-
-			session.update( containing1 );
-			session.update( containing2 );
-			session.update( contained1 );
-			session.update( contained2 );
 		} );
 
 		inTransaction( session -> {

hibernate-core/src/test/java/org/hibernate/orm/test/inheritance/discriminator/SingleTableInheritancePersistTest.java

@@ -16,9 +16,7 @@ import org.hibernate.testing.TestForIssue;
 import org.hibernate.testing.orm.junit.DomainModel;
 import org.hibernate.testing.orm.junit.SessionFactory;
 import org.hibernate.testing.orm.junit.SessionFactoryScope;
-import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import jakarta.persistence.CascadeType;
@@ -225,10 +223,10 @@ public class SingleTableInheritancePersistTest {
 
 		private String favouriteToy;
 
-		@OneToOne
+		@ManyToOne
 		private Woman mother;
 
-		@OneToOne
+		@ManyToOne
 		private Man father;
 
 		public Child() {

hibernate-core/src/test/java/org/hibernate/orm/test/inheritance/discriminator/TablePerClassInheritancePersistTest.java

@@ -206,10 +206,10 @@ public class TablePerClassInheritancePersistTest {
 
 		private String favouriteToy;
 
-		@OneToOne
+		@ManyToOne
 		private Woman mother;
 
-		@OneToOne
+		@ManyToOne
 		private Man father;
 
 		public Child() {

hibernate-core/src/test/java/org/hibernate/orm/test/inheritance/discriminator/TablePerClassInheritanceTest.java

@@ -16,6 +16,7 @@ import jakarta.persistence.Entity;
 import jakarta.persistence.Id;
 import jakarta.persistence.Inheritance;
 import jakarta.persistence.InheritanceType;
+import jakarta.persistence.ManyToOne;
 import jakarta.persistence.OneToMany;
 import jakarta.persistence.OneToOne;
 
@@ -166,10 +167,10 @@ public class TablePerClassInheritanceTest {
 
 		private String favouriteToy;
 
-		@OneToOne
+		@ManyToOne
 		private Woman mother;
 
-		@OneToOne
+		@ManyToOne
 		private Man father;
 
 		public Child() {

hibernate-core/src/test/java/org/hibernate/orm/test/insertordering/InsertOrderingSelfReferenceSingleTableInheritance.java

@@ -77,12 +77,9 @@ public class InsertOrderingSelfReferenceSingleTableInheritance {
 	@Test
 	public void test2(EntityManagerFactoryScope scope) {
 		scope.inTransaction( entityManager -> {
-			NodeLongValue aparam = new NodeLongValue();
+			ContentNode xa = new ContentNode(new NodeLongValue(123L), null, null );
-			aparam.setLongValue( 123L );
+			ContentNode xb = new ContentNode(new NodeLongValue(123L), null, null );
-
+			ContentNode xc = new ContentNode(new NodeLongValue(123L), xb, null );
-			ContentNode xa = new ContentNode( aparam, null, null );
-			ContentNode xb = new ContentNode( aparam, null, null );
-			ContentNode xc = new ContentNode( aparam, xb, null );
 
 			NodeLink nl = new NodeLink( xc );
 
@@ -118,8 +115,9 @@ public class InsertOrderingSelfReferenceSingleTableInheritance {
 			NodeStringValue stringVal = new NodeStringValue();
 			stringVal.setStringValue( "Node 123" );
 
+			ContentNode cn0 = new ContentNode( null, null, null );
 			ContentNode cn1 = new ContentNode( stringVal, null, null );
-			ContentNode cn2 = new ContentNode( longVal, cn1, null );
+			ContentNode cn2 = new ContentNode( longVal, cn0, null );
 
 			ContentNode cn3 = new ContentNode( null, cn1, cn2 );
 
@@ -345,6 +343,11 @@ public class InsertOrderingSelfReferenceSingleTableInheritance {
 			this.longValue = longValue;
 		}
 
+		public NodeLongValue(Long longValue) {
+			super();
+			this.longValue = longValue;
+		}
+
 		public NodeLongValue() {
 			super();
 		}

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/onetoone/primarykey/NullablePrimaryKeyTest.java

@@ -54,7 +54,7 @@ public class NullablePrimaryKeyTest {
 					metadata,
 					false
 			);
-			String expectedMappingTableSql = "create table personAddress (address_id bigint, " +
+			String expectedMappingTableSql = "create table personAddress (address_id bigint unique, " +
 					"person_id bigint not null, primary key (person_id))";
 
 			assertEquals( "Wrong SQL", expectedMappingTableSql, commands.get( 2 ) );

hibernate-core/src/test/java/org/hibernate/orm/test/ondelete/toone/ToOneOnDeleteTest.java

@@ -120,7 +120,7 @@ public class ToOneOnDeleteTest {
 
 		private String name;
 
-		@OneToOne
+		@ManyToOne
 		@OnDelete(action = OnDeleteAction.CASCADE)
 		private Child parent;
 	}

hibernate-envers/src/test/java/org/hibernate/envers/test/integration/query/InheritanceAssociationToOneInnerJoinTest.java

@@ -13,7 +13,6 @@ import jakarta.persistence.Id;
 import jakarta.persistence.Inheritance;
 import jakarta.persistence.InheritanceType;
 import jakarta.persistence.ManyToOne;
-import jakarta.persistence.OneToOne;
 import jakarta.persistence.criteria.JoinType;
 
 import org.hibernate.envers.Audited;
@@ -131,7 +130,7 @@ public class InheritanceAssociationToOneInnerJoinTest extends BaseEnversJPAFunct
 	public static class EntityA {
 		@Id
 		private Integer id;
-		@OneToOne
+		@ManyToOne
 		private EntityD relationToD;
 		@ManyToOne
 		private EntityC relationToC;

hibernate-envers/src/test/java/org/hibernate/orm/test/envers/integration/onetoone/bidirectional/BiRefIngEntity.java

@@ -8,7 +8,7 @@ package org.hibernate.orm.test.envers.integration.onetoone.bidirectional;
 
 import jakarta.persistence.Entity;
 import jakarta.persistence.Id;
-import jakarta.persistence.OneToOne;
+import jakarta.persistence.ManyToOne;
 
 import org.hibernate.envers.Audited;
 
@@ -24,7 +24,7 @@ public class BiRefIngEntity {
 	private String data;
 
 	@Audited
-	@OneToOne
+	@ManyToOne
 	private BiRefEdEntity reference;
 
 	public BiRefIngEntity() {

hibernate-envers/src/test/java/org/hibernate/orm/test/envers/integration/onetoone/unidirectional/UniRefIngEntity.java

@@ -8,7 +8,7 @@ package org.hibernate.orm.test.envers.integration.onetoone.unidirectional;
 
 import jakarta.persistence.Entity;
 import jakarta.persistence.Id;
-import jakarta.persistence.OneToOne;
+import jakarta.persistence.ManyToOne;
 
 import org.hibernate.envers.Audited;
 
@@ -26,7 +26,7 @@ public class UniRefIngEntity {
 	private String data;
 
 	@Audited
-	@OneToOne
+	@ManyToOne
 	private UniRefEdEntity reference;
 
 	public UniRefIngEntity() {