tests: ensure -N/--no-default-middleware not supported in config.ru

Continue to make it easy to migrate AWAY from unicorn because
vendor lock-in is the worst thing, especially if it's on us.

t/t0301-no-default-middleware-ignored-in-config.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+. ./test-lib.sh
+t_plan 3 "-N / --no-default-middleware option not supported in config.ru"
+
+t_begin "setup and start" && {
+	unicorn_setup
+	RACK_ENV=development unicorn -D -c $unicorn_config t0301.ru
+	unicorn_wait_start
+}
+
+t_begin "check switches parsed as expected and -N ignored for Rack::Lint" && {
+	debug=false
+	lint=
+	eval "$(curl -sf http://$listen/vars)"
+	test x"$debug" = xtrue
+	test x"$lint" != x
+	test -f "$lint"
+}
+
+t_begin "killing succeeds" && {
+	kill $unicorn_pid
+	check_stderr
+}
+
+t_done

t/t0301.ru

@@ -0,0 +1,13 @@
+#\-N --debug
+run(lambda do |env|
+  case env['PATH_INFO']
+  when '/vars'
+    b = "debug=#{$DEBUG.inspect}\n" \
+        "lint=#{caller.grep(%r{rack/lint\.rb})[0].split(':')[0]}\n"
+  end
+  h = {
+    'Content-Length' => b.size.to_s,
+    'Content-Type' => 'text/plain',
+  }
+  [ 200, h, [ b ] ]
+end)