[Demonstration 1]

[Buggy Method]
public final static char[] escapeString(final String value) {
    StringBuilder sb = new StringBuilder();
    int last = 0;
    final int length = value.length();
    for (int i = 0; i < length; i++) {
        char c = value.charAt(i);
        char[] replacement;
        if (c < 128) {
            replacement = REPLACEMENT_CHARS[c];
            if (replacement == null) {
                continue;
            }
        } else if (c == '\u2028') {
            replacement = "\\u2028".toCharArray();
        } else if (c == '\u2029') {
            replacement = "\\u2029".toCharArray();
        } else {
            continue;
        }
        if (last < i) {
            sb.append(value, last, i - last);
        }
        sb.append(replacement, 0, replacement.length);
        last = i + 1;
    }
    if (last < length) {
        sb.append(value, last, length);
    }
    return sb.toString().toCharArray();
}

[Buggy Hunk]
sb.append(value, last, i - last);

[Patch]
sb.append(value, last, i);

[Demonstration 2]

[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));