Tread entities nested in arrays like PUT for merge patch requests.

Fixes GH-2358.

Author: odrotbohm

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/json/DomainObjectReader.java

@@ -402,7 +402,7 @@ private boolean handleArrayNode(ArrayNode array, Collection<Object> collection,
 			if (ObjectNode.class.isInstance(jsonNode)) {
 
 				nestedObjectFound = true;
-				doMerge((ObjectNode) jsonNode, next, mapper);
+				readPut((ObjectNode) jsonNode, next, mapper);
 			}
 		}
 

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/json/DomainObjectReaderUnitTests.java

@@ -237,8 +237,9 @@ void doesNotApplyInputToReadOnlyFields() throws Exception {
 		assertThat(reader.readPut(node, sample, mapper).createdDate).isEqualTo(reference);
 	}
 
-	@Test // DATAREST-931
-	void readsPatchForEntityNestedInCollection() throws Exception {
+	@Test // DATAREST-931, GH-2358
+	// https://datatracker.ietf.org/doc/html/rfc7386#section-2
+	void handlesEntityNestedInAnArrayLikePutForPatchRequest() throws Exception {
 
 		Phone phone = new Phone();
 		phone.creationDate = new GregorianCalendar();
@@ -251,7 +252,7 @@ void readsPatchForEntityNestedInCollection() throws Exception {
 
 		User result = reader.read(source, user, new ObjectMapper());
 
-		assertThat(result.phones.get(0).creationDate).isNotNull();
+		assertThat(result.phones.get(0).creationDate).isNull();
 	}
 
 	@Test // DATAREST-919