FULL PRODUCT VERSION :
jdk 8

ADDITIONAL OS VERSION INFORMATION :
Windows Windows[Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
Hello.The servlet below should throw IllegalStateException in case we don't specify asyncSupported=true.But it doesn't.

//Async is unsupported for this servlet

public class AsyncServlet extends HttpServlet {

    public void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        out.println(request.isAsyncSupported());
        AsyncContext aContext = request.startAsync();// it should throw IllegalStateException on this line.
        out.println("Java Servlet bug");
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

}


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
out.println(request.isAsyncSupported());
        AsyncContext aContext = request.startAsync(); // it should throw IllegalStateException on this line.whether request.isAsyncSupported() is called
        out.println("Java Servlet bug");

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
it should throw IllegalStateException .whether request.isAsyncSupported() is called
ACTUAL -
Only "false" printed on browser.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
out.println(request.isAsyncSupported());
        AsyncContext aContext = request.startAsync(); // it should throw IllegalStateException on this line.whether request.isAsyncSupported() is called
        out.println("Java Servlet bug");
---------- END SOURCE ----------

SUPPORT :
YES