varnishtest "regression for NULL string concatenation"

server s1 {
	rxreq
	expect req.http.Candy == "FOOBAR"
	expect req.http.Cookie == "FOOBAR"
	txresp
} -start

varnish v1 -vcl+backend {
	sub vcl_recv {
		set req.http.Candy = " FOOBAR" + req.http.Cookie;
		set req.http.Cookie = req.http.Cookie + " FOOBAR";
	}
} -start

client c1 {
	txreq
	rxresp
} -run
