[Demonstration 1]

[Buggy Method]
@Override
@Nonnull
public Collection<Firewall> list() throws InternalException, CloudException {
    //GCE has a defacto Firewall for every network so will simply map a fake firewall to networks.
    ProviderContext ctx = provider.getContext();
    if (ctx == null)
        throw new InternalException("No context was established");
    ArrayList<Firewall> firewalls = new ArrayList<Firewall>();
    try {
        Compute gce = provider.getGoogleCompute();
        NetworkList networkList = gce.networks().list(ctx.getAccountNumber()).execute();
        if (null != networkList) {
            List<Network> networks = networkList.getItems();
            FirewallList firewallList = gce.firewalls().list(ctx.getAccountNumber()).execute();
            if (null != firewallList) {
                List<com.google.api.services.compute.model.Firewall> rules = firewallList.getItems();
                if (networks != null && networks.size() > 0) {
                    for (Network network : networks) {
                        List<com.google.api.services.compute.model.Firewall> rulesSubset = new ArrayList<com.google.api.services.compute.model.Firewall>();
                        if (null != rulesSubset) {
                            for (com.google.api.services.compute.model.Firewall rule : rules) if (rule.getNetwork().equals(network.getSelfLink()))
                                rulesSubset.add(rule);
                        }
                        if (network != null) {
                            Firewall firewall = toFirewall(network, rulesSubset);
                            if (firewall != null)
                                firewalls.add(firewall);
                        }
                    }
                }
            }
        }
    } catch (IOException ex) {
        logger.error(ex.getMessage());
        if (ex.getClass() == GoogleJsonResponseException.class) {
            GoogleJsonResponseException gjre = (GoogleJsonResponseException) ex;
            throw new GoogleException(CloudErrorType.GENERAL, gjre.getStatusCode(), gjre.getContent(), gjre.getDetails().getMessage());
        } else
            throw new CloudException("An error occurred while listing Firewalls: " + ex.getMessage());
    }
    return firewalls;
}

[Buggy Hunk]
if (null != rulesSubset) {

[Patch]
if (null != rules) {

[Demonstration 2]

[Buggy Method]
@Override
public boolean apply(SecurityGroup input) {
    return input.getId() == group.getId();
}

[Buggy Hunk]
return input.getId() == group.getId();

[Patch]
return Objects.equal(input.getId(), group.getId());

[Demonstration 3]

[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));