DATAES-797 - Fix MappingElasticsearchConverter recursive descent when reading Map objects.

Original PR: spring-projects#437

Author: sothawo

src/main/java/org/springframework/data/elasticsearch/core/convert/MappingElasticsearchConverter.java

@@ -288,6 +288,8 @@ private <R> R readCollectionValue(@Nullable List<?> source, ElasticsearchPersist
 
 				if (value instanceof List) {
 					target.add(readValue(value, property, property.getTypeInformation().getActualType()));
+				} else if (value instanceof Map) {
+					target.add(readMapValue((Map<String, Object>) value, property, property.getTypeInformation().getActualType()));
 				} else {
 					target.add(readEntity(computeGenericValueTypeForRead(property, value), (Map<String, Object>) value));
 				}

src/test/java/org/springframework/data/elasticsearch/core/convert/MappingElasticsearchConverterUnitTests.java

@@ -677,6 +677,24 @@ void readGenericMapWithSimpleTypes() {
 		assertThat(wrapper.getSchemaLessObject()).isEqualTo(mapWithSimpleValues);
 	}
 
+	@Test // DATAES-797
+	void readGenericListWithMaps() {
+		Map<String, Object> simpleMap = new HashMap<>();
+		simpleMap.put("int", 1);
+
+		List<Map<String, Object>> listWithSimpleMap = new ArrayList<>();
+		listWithSimpleMap.add(simpleMap);
+
+		Map<String, List<Map<String, Object>>> mapWithSimpleList = new HashMap<>();
+		mapWithSimpleList.put("someKey", listWithSimpleMap);
+
+		Document document = Document.create();
+		document.put("schemaLessObject", mapWithSimpleList);
+
+		SchemaLessObjectWrapper wrapper = mappingElasticsearchConverter.read(SchemaLessObjectWrapper.class, document);
+		assertThat(wrapper.getSchemaLessObject()).isEqualTo(mapWithSimpleList);
+	}
+
 	private String pointTemplate(String name, Point point) {
 		return String.format(Locale.ENGLISH, "\"%s\":{\"lat\":%.1f,\"lon\":%.1f}", name, point.getX(), point.getY());
 	}