Avoid NPE on JsonPatches#apply

Author: dai0304

spar-wings-json-patch/src/main/java/jp/xet/sparwings/jackson/patch/JsonPatches.java

@@ -38,12 +38,12 @@ class JsonPatches<T> implements UpdateRequest<T> {
 	@SuppressWarnings("unchecked")
 	public T apply(T original) throws IllegalPatchException {
 		try {
-			JsonPatch patch = JsonPatch.fromJson(this.node);
+			JsonPatch patch = JsonPatch.fromJson(node);
 			JsonNode originalNode = mapper.valueToTree(original);
 			JsonNode patchedNode = patch.apply(originalNode);
 			T patched = mapper.treeToValue(patchedNode, (Class<T>) original.getClass());
 			return patched; // NOPMD
-		} catch (IllegalArgumentException | JsonPatchException | IOException e) {
+		} catch (IllegalArgumentException | JsonPatchException | IOException | NullPointerException e) { // NOPMD
 			throw new IllegalPatchException(e);
 		}
 	}