HHH-14730 Avoid loading the same entity proxy twice for the same result set

hibernate-core/src/main/java/org/hibernate/sql/results/graph/entity/AbstractEntityInitializer.java

@@ -667,17 +667,10 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 			PersistenceContext persistenceContext) {
 		final EntityEntry entry = persistenceContext.getEntry( toInitialize );
 		if ( entry != null ) {
-			if ( entry.getStatus() != Status.LOADING ) {
-				final Object optionalEntityInstance = rowProcessingState.getJdbcValuesSourceProcessingState()
-						.getProcessingOptions()
-						.getEffectiveOptionalObject();
-				// If the instance to initialize is the main entity, we can't skip this
-				// This can happen if we initialize an enhanced proxy
-				if ( !isEntityReturn() || toInitialize != optionalEntityInstance ) {
+			if ( skipInitialization( toInitialize, rowProcessingState, entry ) ) {
 				return;
 			}
 		}
-		}
 
 		final Object entity = persistenceContext.getEntity( entityKey );
 		assert entity == null || entity == toInitialize;
@@ -863,6 +856,25 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 		}
 	}
 
+	protected boolean skipInitialization(
+			Object toInitialize,
+			RowProcessingState rowProcessingState,
+			EntityEntry entry) {
+		// If the instance to initialize is the main entity, we can't skip this
+		// This can happen if we initialize an enhanced proxy
+		if ( entry.getStatus() != Status.LOADING ) {
+			final Object optionalEntityInstance = rowProcessingState.getJdbcValuesSourceProcessingState()
+					.getProcessingOptions()
+					.getEffectiveOptionalObject();
+			// If the instance to initialize is the main entity, we can't skip this
+			// This can happen if we initialize an enhanced proxy
+			if ( !isEntityReturn() || toInitialize != optionalEntityInstance ) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	private boolean isReadOnly(
 			RowProcessingState rowProcessingState,
 			SharedSessionContractImplementor persistenceContext) {

hibernate-core/src/main/java/org/hibernate/sql/results/graph/entity/internal/EntityJoinedFetchInitializer.java

@@ -7,7 +7,12 @@
 package org.hibernate.sql.results.graph.entity.internal;
 
 import org.hibernate.LockMode;
+import org.hibernate.bytecode.enhance.spi.interceptor.EnhancementAsProxyLazinessInterceptor;
+import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.PersistenceContext;
+import org.hibernate.engine.spi.PersistentAttributeInterceptable;
+import org.hibernate.engine.spi.PersistentAttributeInterceptor;
+import org.hibernate.engine.spi.Status;
 import org.hibernate.internal.log.LoggingHelper;
 import org.hibernate.metamodel.mapping.ModelPart;
 import org.hibernate.metamodel.mapping.internal.ToOneAttributeMapping;
@@ -16,6 +21,7 @@ import org.hibernate.sql.results.graph.AssemblerCreationState;
 import org.hibernate.sql.results.graph.DomainResult;
 import org.hibernate.sql.results.graph.entity.AbstractEntityInitializer;
 import org.hibernate.sql.results.graph.entity.EntityResultGraphNode;
+import org.hibernate.sql.results.jdbc.spi.RowProcessingState;
 
 /**
  * @author Andrea Boriero
@@ -80,4 +86,21 @@ public class EntityJoinedFetchInitializer extends AbstractEntityInitializer {
 	public String toString() {
 		return "EntityJoinedFetchInitializer(" + LoggingHelper.toLoggableString( getNavigablePath() ) + ")";
 	}
+
+	@Override
+	protected boolean skipInitialization(
+			Object toInitialize, RowProcessingState rowProcessingState, EntityEntry entry) {
+		if ( toInitialize instanceof PersistentAttributeInterceptable ) {
+			final PersistentAttributeInterceptor interceptor = ( (PersistentAttributeInterceptable) toInitialize ).$$_hibernate_getInterceptor();
+			if ( interceptor instanceof EnhancementAsProxyLazinessInterceptor ) {
+				if ( entry.getStatus() != Status.LOADING ) {
+					// Avoid loading the same entity proxy twice for the same result set: it could lead to errors,
+					// because some code writes to its input (ID in hydrated state replaced by the loaded entity, in particular).
+					return false;
+				}
+				return true;
+			}
+		}
+		return super.skipInitialization( toInitialize, rowProcessingState, entry );
+	}
 }

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/lazytoone/collectioninitializer/InitLazyToOneWithinPaddedCollectionInitializationAllowProxyTest.java

@@ -15,7 +15,6 @@ import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.testing.TestForIssue;
 import org.hibernate.testing.bytecode.enhancement.BytecodeEnhancerRunner;
 import org.hibernate.testing.junit4.BaseNonConfigCoreFunctionalTestCase;
-import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;