[Demonstration 1]

[Buggy Method]
public static String removeHeading(String source, String toRemove) {
    if (toRemove == null) {
        return source;
    }
    source = source.trim();
    int toRemoveLength = toRemove.length();
    if (toRemove.equals(source.substring(0, toRemoveLength))) {
        source = source.substring(toRemoveLength, source.length());
    }
    return source;
}

[Buggy Hunk]
if (toRemove.equals(source.substring(0, toRemoveLength))) {

[Patch]
if (source.length() >= toRemoveLength && toRemove.equals(source.substring(0, toRemoveLength))) {

[Demonstration 2]

[Buggy Method]
@Override
public TSBoolean toBoolean() {
    // +0, -0, NaN => false
    // else => true
    // http://www.ecma-international.org/ecma-262/5.1/#sec-9.2
    return value == zeroValue.getInternal() ? TSBoolean.falseValue : TSBoolean.trueValue;
}

[Buggy Hunk]
return value == zeroValue.getInternal()

[Patch]
return this == plusZeroValue || this == minusZeroValue || Double.isNaN(value)

[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));