Sometime withForm do not work

I found that the withForm did not work in my project sometimes, then I read the resource code of Grails, I found that there was a bug in the file WithFormMethod.groovy,

TokenResponseHandler withForm(HttpServletRequest request, Closure callable) {
TokenResponseHandler handler
if (isTokenValid(request))

{ resetToken(request) handler = new ValidResponseHandler(callable?.call()) }
......
}
the isTokenValid(request) and resetToken(request) are not in the same synchronized block

change into:

TokenResponseHandler withForm(HttpServletRequest request, Closure callable) {
TokenResponseHandler handler
synchronized(this){
if (isTokenValid(request)) { resetToken(request) handler = new ValidResponseHandler(callable?.call()) }

......
}

and remove the "synchronized" in method isTokenValid and resetToken