redirectAfterLogout prepends servlet context to the target, when it's already there

In SlingAuthenticator.redirectAfterLogout, a call is made to AuthUtil.isRedirectValid(request, target) which expects the target to contain the servlet context path.

When the validation is made, the call for redirection appends the servlet context to the same target, leading to a duplicated context:
Line 1417: response.sendRedirect(request.getContextPath() + target);

Calling http://localhost:8080/dev/system/sling/logout?resource=/dev/content/node1.html redirects to http://localhost:8080/dev/dev/content/node1.html