Fix updating nested collection fields using JSON Patch

Fix updating nested collection fields using JSON Patch

Closes spring-projects#2401
Related tickets spring-projects#2401

Author: EdikAmperyan

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

@@ -74,7 +74,6 @@ private String verify(String pointer, Class<?> type, BiFunction<String, Class<?>
 			return pointer;
 		}
 
-		PropertyPath base = null;
 		StringBuilder result = new StringBuilder();
 		TypeInformation<?> currentType = ClassTypeInformation.from(type);
 
@@ -108,13 +107,11 @@ private String verify(String pointer, Class<?> type, BiFunction<String, Class<?>
 					.orElseThrow(() -> reject(segment, rejectType, pointer, qualifier));
 
 			try {
-				base = base == null ? PropertyPath.from(property, type) : base.nested(segment);
+				currentType = PropertyPath.from(property, currentType).getTypeInformation();
 			} catch (PropertyReferenceException o_O) {
 				throw reject(segment, rejectType, pointer, qualifier);
 			}
 
-			currentType = base.getTypeInformation();
-
 			result.append("/").append(property);
 		}