[Demonstration 1]

[Buggy Method]
public static Result service(String ownerName, String projectName, String service, boolean isAdvertise) throws IOException, UnsupportedOperationException, ServletException {
    if (!isSupportedService(service)) {
        return forbidden(String.format("Unsupported service: '%s'", service));
    }
    Project project = Project.findByOwnerAndProjectName(ownerName, projectName);
    if (project == null) {
        return notFound();
    }
    models.User user = UserApp.currentUser();
    if (!isAllowed(project, service)) {
        if (user.isAnonymous()) {
            return BasicAuthAction.unauthorized(response());
        } else {
            // If you want the Git client showing your custom message to
            // the user, the Content-Type should be exact "text/plain"
            // without any parameter. For more details, see the code at
            // https://github.com/git/git/commit/426e70d4a11ce3b4f70636d57c6a0ab16ae08a00#diff-eea0ad565ec5903a11b6023755d491cfR154
            response().setHeader("Content-Type", "text/plain");
            return forbidden(String.format("'%s' has no permission to '%s/%s'.", user.name, ownerName, projectName));
        }
    }
    if (isAdvertise) {
        return ok(RepositoryService.gitAdvertise(project, service, response()));
    } else {
        if (request().body().isMaxSizeExceeded()) {
            return status(REQUEST_ENTITY_TOO_LARGE);
        } else {
            user.visits(project);
            return ok(RepositoryService.gitRpc(project, service, request(), response()));
        }
    }
}

[Buggy Hunk]
user.name, ownerName, projectName));

[Patch]
user.loginId, ownerName, projectName));

[Demonstration 2]

[Buggy Method]
public static ListNode mergeKLists(ArrayList<ListNode> lists) {
    if (lists.isEmpty()) {
        return null;
    }
    //PriorityQueue is a sorted queue
    PriorityQueue<ListNode> pq = new PriorityQueue<>(lists.size(), (ListNode a, ListNode b) -> {
        if (a.getData() > b.getData) {
            return 1;
        } else if (a.getData() == b.getData()) {
            return 0;
        } else {
            return -1;
        }
    });
    //add first node of each list to the queue
    for (ListNode list : lists) {
        if (list != null) {
            pq.add(list);
        }
    }
    ListNode head = new ListNode(0);
    ListNode p = head;
    while (pq.size() > 0) {
        //poll() retrieves and removes the head of the queue - q.
        ListNode temp = pq.poll();
        p.next = temp;
        //keep adding next element of each list
        if (temp.next != null) {
            pq.add(temp.next);
        }
        p = p.next;
    }
    return head.next;
}

[Buggy Hunk]
if (a.getData() > b.getData) {

[Patch]
if (a.getData() > b.getData()) {