[#2007] NPE retrieving Entity with composite id mixing ManyToOne with basic attributes

hibernate-reactive-core/src/main/java/org/hibernate/reactive/sql/results/graph/embeddable/internal/ReactiveNonAggregatedIdentifierMappingInitializer.java

@@ -62,7 +62,7 @@ public CompletionStage<Void> reactiveResolveKey(NonAggregatedIdentifierMappingIn
 			final RowProcessingState rowProcessingState = data.getRowProcessingState();
 			final boolean[] dataIsMissing = {false};
 			return loop( getInitializers(), initializer -> {
-				if ( dataIsMissing[0] ) {
+				if ( dataIsMissing[0] || initializer == null ) {
 					return voidFuture();
 				}
 				final InitializerData subData = ( (ReactiveInitializer<?>) initializer )

hibernate-reactive-core/src/test/java/org/hibernate/reactive/ManyToOneIdClassTest.java

@@ -0,0 +1,141 @@
+/* Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright: Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.reactive;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import io.vertx.junit5.Timeout;
+import io.vertx.junit5.VertxTestContext;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.ManyToOne;
+
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static org.assertj.core.api.Assertions.assertThat;
+
+@Timeout(value = 1, timeUnit = MINUTES)
+public class ManyToOneIdClassTest extends BaseReactiveTest {
+
+	private final static String USER_NAME = "user";
+	private final static String SUBSYSTEM_ID = "1";
+
+	@Override
+	protected Collection<Class<?>> annotatedEntities() {
+		return List.of( SystemUser.class, Subsystem.class );
+	}
+
+	@BeforeEach
+	public void populateDb(VertxTestContext context) {
+		Subsystem subsystem = new Subsystem( SUBSYSTEM_ID, "sub 1" );
+		SystemUser systemUser = new SystemUser( subsystem, USER_NAME, "system 1" );
+		test(
+				context, getMutinySessionFactory()
+						.withTransaction( (s, t) -> s.persistAll( subsystem, systemUser ) )
+		);
+	}
+
+	@AfterEach
+	public void after(VertxTestContext context) {
+		test( context, cleanDb() );
+	}
+
+	@Test
+	public void testQuery(VertxTestContext context) {
+		test(
+				context, openSession()
+						.thenAccept( session -> session.createQuery( "SELECT s FROM SystemUser s", SystemUser.class )
+								.getResultList().thenAccept( list -> {
+									assertThat( list.size() ).isEqualTo( 1 );
+									SystemUser systemUser = list.get( 0 );
+									assertThat( systemUser.getSubsystem().getId() ).isEqualTo( SUBSYSTEM_ID );
+									assertThat( systemUser.getUsername() ).isEqualTo( USER_NAME );
+								} ) )
+		);
+	}
+
+	@Entity(name = "SystemUser")
+	@IdClass(PK.class)
+	public static class SystemUser {
+
+		@Id
+		@ManyToOne(fetch = FetchType.LAZY)
+		private Subsystem subsystem;
+
+		@Id
+		private String username;
+
+		private String name;
+
+		public SystemUser() {
+		}
+
+		public SystemUser(Subsystem subsystem, String username, String name) {
+			this.subsystem = subsystem;
+			this.username = username;
+			this.name = name;
+		}
+
+		public Subsystem getSubsystem() {
+			return subsystem;
+		}
+
+		public String getUsername() {
+			return username;
+		}
+
+		public String getName() {
+			return name;
+		}
+	}
+
+	@Entity(name = "Subsystem")
+	public static class Subsystem {
+
+		@Id
+		private String id;
+
+		private String description;
+
+		public Subsystem() {
+		}
+
+		public Subsystem(String id, String description) {
+			this.id = id;
+			this.description = description;
+		}
+
+		public String getId() {
+			return id;
+		}
+
+		public String getDescription() {
+			return description;
+		}
+	}
+
+	public static class PK {
+
+		private Subsystem subsystem;
+
+		private String username;
+
+		public PK(Subsystem subsystem, String username) {
+			this.subsystem = subsystem;
+			this.username = username;
+		}
+
+		private PK() {
+		}
+	}
+
+}