Test that we detect and handle symbols of a bogus kind in expressions.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5390 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishtest/tests/v00020.vtc

@@ -33,3 +33,9 @@ varnish v1 -badvcl {
 
 	}
 }
+
+varnish v1 -badvcl {
+	sub vcl_recv {
+		set req.http.foo = vcl_recv;
+	}
+}