[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]
@RequestMapping(value = "/user/{username}", method = RequestMethod.POST)
public String login(@PathVariable("username") String username, @RequestBody String value) {
    boolean failed = false;
    //take in input and create variables for each entry
    JSONObject input = null;
    try {
        input = new JSONObject(new JSONTokener(value));
    } catch (JSONException e) {
        failed = true;
    }
    String password = null;
    try {
        password = input.getString("password");
    } catch (JSONException e) {
        //error
        failed = true;
    } catch (NullPointerException e) {
        failed = true;
    }
    //check values are present
    if (password == null) {
        failed = true;
    }
    User user = Server.getUser(username);
    user = Server.loginUser(user, password);
    if (user == null)
        failed = true;
    if (!failed) {
        return getPlayer(username, user.gamecode);
    }
    //Set up response object
    JSONObject output = new JSONObject();
    try {
        //info no matter what
        output.put(ServerConfiguration.success, !failed);
    } catch (JSONException e) {
        //really bad error
        System.out.println("JSONException while attempting to login");
        e.printStackTrace();
    }
    return output.toString();
}

[Buggy Hunk]
return getPlayer(username, user.gamecode);

[Patch]
return getPlayer(username);

[Demonstration 3]

[Buggy Method]
public void sendProperty(int portNum, int value) {
    try {
        super.setProperty(map.findPort(portNum).getPortName(), value);
        super.updateSubscribedProperties(15000);
    } catch (Exception e) {
        logger.warn(TAG, "failed to update property " + map.getRegisterMap().get(portNum));
    }
}

[Buggy Hunk]
logger.warn(TAG, "failed to update property " + map.getRegisterMap().get(portNum));

[Patch]
logger.warn(TAG, "failed to update property " + map.findPort(portNum));