[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/coupons/can/{couponId}", method = RequestMethod.GET)
@ResponseBody
public DajiaResult canRequestCoupon(HttpServletRequest request, HttpServletResponse response, @PathVariable("couponId") Long couponId) {
    User user = getLoginUser(request, response, userRepo, false);
    Long userId = user.userId;
    DajiaResult result;
    try {
        UserCoupon userCoupon = userCouponService.userCouponRepo.findByUserIdAndCouponId(userId, couponId);
        if (null != userCoupon) {
            result = DajiaResult.successReturn("已经领过相同的优惠券", null, Boolean.FALSE);
        } else {
            result = DajiaResult.successReturn(COMMON_MSG_QUERY_OK, null, Boolean.TRUE);
        }
    } catch (Exception ex) {
        result = DajiaResult.systemError(COMMON_MSG_QUERY_FAILED + ",系统异常", null, ex);
    }
    String input = String.format("user=%s,couponId=%d", user.userId, couponId);
    logger.info(String.format("%s|%s|%s", "canRequestCoupon", result, input));
    return result;
}

[Buggy Hunk]
UserCoupon userCoupon = userCouponService.userCouponRepo.findByUserIdAndCouponId(userId, couponId);

[Patch]
UserCoupon userCoupon = userCouponRepo.findByUserIdAndCouponId(userId, couponId);

[Demonstration 3]

[Buggy Method]
public String extractBody(int maxPayloadLength) {
    String method = request.getMethod();
    if ("GET".equals(method)) {
        return "";
    }
    MediaType mediaType = MediaType.parseMediaType(request.getHeader(HttpHeaders.CONTENT_TYPE));
    RequestBodyExtractor bodyExtractor;
    if ("POST".equals(method) && MediaType.APPLICATION_FORM_URLENCODED.isCompatibleWith(mediaType)) {
        bodyExtractor = new FormUrlencodedRequestBodyExtractor();
    } else {
        bodyExtractor = new DefaultRequestBodyExtractor();
    }
    return bodyExtractor.extractBody(request, maxPayloadLength);
}

[Buggy Hunk]
if ("GET".equals(method)) {

[Patch]
if ("GET".equals(method) || "OPTIONS".equals(method)) {