[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 Vector projectOrthogonal(List<Vector> vlist, Map<Integer, Double> alpha) {
    Vector b = this;
    for (int i = 0; i < vlist.size(); ++i) {
        Vector v = vlist.get(i);
        double norm_a = v.multiply(v);
        if (DoubleUtils.isZero(norm_a)) {
            return new Vector(dimension);
        }
        double sigma = multiply(v) / norm_a;
        Vector v_parallel = v.multiply(sigma);
        alpha.put(i, sigma);
        b = b.minus(v_parallel);
    }
    return b;
}

[Buggy Hunk]
double norm_a = v.multiply(v);

[Patch]
double norm_a = Math.sqrt(v.multiply(v));

[Demonstration 3]

[Buggy Method]
private double factorial(double v) {
    v = (int) v;
    Log.d("Debug", "Value of i = " + v);
    if (v > 1)
        return v * factorial(v - 1);
    else
        return v;
}

[Buggy Hunk]
v = (int)v;

[Patch]
v = Math.floor(v);