Fixed NullPointerException in EntityGraphMapper::mapEntityReference

core/src/main/java/org/neo4j/ogm/context/EntityGraphMapper.java

@@ -425,7 +425,7 @@ private void mapEntityReferences(final Object entity, NodeBuilder nodeBuilder, i
 
                 if (isRelationshipEntity(relatedObject)) {
                     ClassInfo declaredObjectInfo = metaData.classInfo(relationshipType);
-                    if (declaredObjectInfo.isAbstract()) {
+                    if (declaredObjectInfo != null && declaredObjectInfo.isAbstract()) {
                         final ClassInfo relatedObjectClassInfo = metaData.classInfo(relatedObject);
                         if (!relatedObjectClassInfo.neo4jName().equals(directedRelationship.type())) {
                             directedRelationship = new DirectedRelationship(relatedObjectClassInfo.neo4jName(),

neo4j-ogm-tests/neo4j-ogm-integration-tests/src/test/java/org/neo4j/ogm/persistence/model/EntityGraphMapperTest.java

@@ -39,6 +39,7 @@
 import org.neo4j.ogm.context.EntityMapper;
 import org.neo4j.ogm.context.MappingContext;
 import org.neo4j.ogm.cypher.compiler.Compiler;
+import org.neo4j.ogm.cypher.query.CypherQuery;
 import org.neo4j.ogm.domain.blog.Post;
 import org.neo4j.ogm.domain.education.Course;
 import org.neo4j.ogm.domain.education.School;
@@ -58,6 +59,11 @@
 import org.neo4j.ogm.persistence.examples.versioned_rel_entity.A;
 import org.neo4j.ogm.persistence.examples.versioned_rel_entity.B;
 import org.neo4j.ogm.persistence.examples.versioned_rel_entity.R;
+import org.neo4j.ogm.persistence.model.gh1134.RelEntity;
+import org.neo4j.ogm.persistence.model.gh1134.NodeWithSomewhatInvalidRelationshipDeclaration;
+import org.neo4j.ogm.request.OptimisticLockingConfig;
+import org.neo4j.ogm.request.Statement;
+import org.neo4j.ogm.request.StatementFactory;
 import org.neo4j.ogm.request.Statements;
 import org.neo4j.ogm.session.Session;
 import org.neo4j.ogm.session.SessionFactory;
@@ -943,6 +949,37 @@ void shouldNotMessUpMixedTypedLists() {
         });
     }
 
+    @Test
+    void mappingEntityRefMustCheckForNullRel() {
+
+        mappingMetadata = new MetaData("org.neo4j.ogm.persistence.model.gh1134");
+        mappingContext = new MappingContext(mappingMetadata);
+
+        EntityGraphMapper mapper = new EntityGraphMapper(mappingMetadata, mappingContext);
+        NodeWithSomewhatInvalidRelationshipDeclaration start = new NodeWithSomewhatInvalidRelationshipDeclaration();
+        start.setId("s");
+        NodeWithSomewhatInvalidRelationshipDeclaration end = new NodeWithSomewhatInvalidRelationshipDeclaration();
+        end.setId("e");
+        RelEntity rel = new RelEntity(start, end);
+        start.setRelatedObject(rel);
+
+        Compiler compiler = mapper.map(start).getCompiler();
+        compiler.useStatementFactory(new StatementFactory() {
+            @Override
+            public Statement statement(String statement, Map<String, Object> parameters) {
+                return new CypherQuery(statement, parameters);
+            }
+
+            @Override
+            public Statement statement(String statement, Map<String, Object> parameters,
+                OptimisticLockingConfig config) {
+                return new CypherQuery(statement, parameters);
+            }
+        });
+        assertThat(compiler.createRelationshipsStatements().stream().map(Statement::getStatement)).first()
+            .isEqualTo("UNWIND $rows as row MATCH (startNode) WHERE ID(startNode) = row.startNodeId WITH row,startNode MATCH (endNode) WHERE ID(endNode) = row.endNodeId MERGE (startNode)-[rel:`whatever`]->(endNode) RETURN row.relRef as ref, ID(rel) as id, $type as type");
+    }
+
     @Test // GH-902
     @SuppressWarnings("unchecked")
     void nestedListsWithDomainModel() {

neo4j-ogm-tests/neo4j-ogm-integration-tests/src/test/java/org/neo4j/ogm/persistence/model/gh1134/NodeWithSomewhatInvalidRelationshipDeclaration.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2002-2024 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.neo4j.ogm.persistence.model.gh1134;
+
+import org.neo4j.ogm.annotation.Id;
+import org.neo4j.ogm.annotation.NodeEntity;
+import org.neo4j.ogm.annotation.Relationship;
+
+@NodeEntity
+public class NodeWithSomewhatInvalidRelationshipDeclaration {
+    @Id
+    private String id;
+
+    @Relationship(type = "whatever")
+    private RelEntity relatedObject;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public RelEntity getRelatedObject() {
+        return relatedObject;
+    }
+
+    public void setRelatedObject(RelEntity relatedObject) {
+        this.relatedObject = relatedObject;
+    }
+}

neo4j-ogm-tests/neo4j-ogm-integration-tests/src/test/java/org/neo4j/ogm/persistence/model/gh1134/RelEntity.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2002-2024 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.neo4j.ogm.persistence.model.gh1134;
+
+import org.neo4j.ogm.annotation.EndNode;
+import org.neo4j.ogm.annotation.RelationshipEntity;
+import org.neo4j.ogm.annotation.StartNode;
+
+@RelationshipEntity
+public class RelEntity {
+
+    public Long id;
+
+    @StartNode
+    private NodeWithSomewhatInvalidRelationshipDeclaration start;
+
+    @EndNode
+    private NodeWithSomewhatInvalidRelationshipDeclaration end;
+
+    public RelEntity(
+        NodeWithSomewhatInvalidRelationshipDeclaration start, NodeWithSomewhatInvalidRelationshipDeclaration end) {
+        this.end = end;
+        this.start = start;
+    }
+}