Fixed EntityGraphFactory overwriting subgraphs

Closes #2527

Author: pstrnad

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/EntityGraphFactory.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.jpa.repository.support;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 
 import jakarta.persistence.EntityGraph;
@@ -27,6 +29,7 @@
  * Factory class to create an {@link EntityGraph} from a collection of property paths.
  *
  * @author Jens Schauder
+ * @author Petr Strnad
  * @since 2.6
  */
 abstract class EntityGraphFactory {
@@ -42,16 +45,20 @@ abstract class EntityGraphFactory {
 	public static <T> EntityGraph<T> create(EntityManager entityManager, Class<T> domainType, Set<String> properties) {
 
 		EntityGraph<T> entityGraph = entityManager.createEntityGraph(domainType);
+		Map<String, Subgraph<Object>> existingSubgraphs = new HashMap<>();
 
 		for (String property : properties) {
 
 			Subgraph<Object> current = null;
+			String currentFullPath = "";
 
 			for (PropertyPath path : PropertyPath.from(property, domainType)) {
 
+				currentFullPath += path.getSegment() + ".";
 				if (path.hasNext()) {
-					current = current == null ? entityGraph.addSubgraph(path.getSegment())
-							: current.addSubgraph(path.getSegment());
+					final Subgraph<Object> finalCurrent = current;
+					current = current == null ? existingSubgraphs.computeIfAbsent(currentFullPath, k -> entityGraph.addSubgraph(path.getSegment()))
+							: existingSubgraphs.computeIfAbsent(currentFullPath, k -> finalCurrent.addSubgraph(path.getSegment()));
 					continue;
 				}
 

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/support/EntityGraphFactoryUnitTests.java

@@ -31,6 +31,7 @@
  * Unit tests for {@link EntityGraphFactory}.
  *
  * @author Jens Schauder
+ * @author Petr Strnad
  */
 @SuppressWarnings("rawtypes")
 class EntityGraphFactoryUnitTests {
@@ -61,12 +62,13 @@ void simpleSetOfPropertiesGetRegistered() {
 	@Test
 	void setOfCompositePropertiesGetRegisteredPiecewise() {
 
-		HashSet<String> properties = new HashSet<>(asList("one.two", "eins.zwei.drei"));
+		HashSet<String> properties = new HashSet<>(asList("one.one", "one.two", "eins.zwei.drei"));
 
 		entityGraph = EntityGraphFactory.create(em, DummyEntity.class, properties);
 
 		verify(entityGraph).addSubgraph("one");
 		Subgraph<?> one = entityGraph.addSubgraph("one");
+		verify(one).addAttributeNodes("one");
 		verify(one).addAttributeNodes("two");
 
 		verify(entityGraph).addSubgraph("eins");