[Demonstration 1]

[Buggy Method]
private boolean aggregableWithScript(UnderlayItem newItem, UnderlayItem topoStoreItem) {
    ScriptResult scriptResult = new ScriptResult();
    scriptEngine.put("aggregable", scriptResult);
    scriptEngine.put("originalItem", topoStoreItem);
    scriptEngine.put("newItem", newItem);
    try {
        scriptEngine.eval(script);
        return scriptResult.getResult();
    } catch (ScriptException e) {
        throw new IllegalStateException("Exception during script evaluation: " + script, e);
    }
}

[Buggy Hunk]
private boolean aggregableWithScript(UnderlayItem newItem, UnderlayItem topoStoreItem) {

[Patch]
private synchronized boolean aggregableWithScript(UnderlayItem newItem, UnderlayItem topoStoreItem) {

[Demonstration 2]

[Buggy Method]
private void checkAttachmentSizeLimit(InputStream input) {
    byte[] bytes = new byte[1024 * 64];
    int bytesRead;
    long totalBytes = 0;
    try {
        while ((bytesRead = input.read(bytes)) > 0) {
            totalBytes = totalBytes + bytesRead;
        }
        if (totalBytes / 1024 > 15000)
            throw new IOException("Attachment size exceeds 15 MB limit.");
    } catch (IOException e) {
        throw new RuntimeException("Error reading input. " + e.getMessage(), e);
    }
}

[Buggy Hunk]
throw new RuntimeException("Error reading input. "+e.getMessage(), e);

[Patch]
throw new RuntimeException(e.getMessage(), e);

[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));