CustomLayout URL's Incorrect

I am trying to add a custom layout that has a dynamic background image. I am using the following code

private static final String LAYOUT_TEMPLATE = "<div class=\"banner\" style=\"background-image: url('%s');\">"
        + "<div location=\"content\"></div>"
        + "</div>";

private static String layout(String url) {
    return String.format(LAYOUT_TEMPLATE, url);

public ProfileBioComponent(String url) {
    String layout = layout(url);


When I print out the values I am getting correct code:


[/code]But when it is actually rendered, it is prepending the background-image url with the theme/layouts directory:
<div class="banner" style="background-image: url( http://localhost:8080/VAADIN/themes/valo/layouts/'' );">
    <div location="content" class="v-align-middle">...</div>

After a quick search I found
this bug
that mentions this happening in img src properties. I am guessing it is a similar fix. Should I submit a ticket?

Are there any work arounds that I can use in the mean time?

FUN FACT: If you change the single quotes to double quotes in the css url function then it works! The following is my final template that renders correctly.

private static final String LAYOUT_TEMPLATE = "<div class=\"banner\" style='background-image: url(\"%s\");'>"

            + "<div location=\"content\"></div>"

            + "</div>";