proper language selection for anonymous

app/controllers/I18n.scala

@@ -12,17 +12,20 @@ object I18n extends LilaController {
 
   private def env = Env.i18n
 
-  def select = AuthBody { implicit ctx =>
-    me =>
-      import play.api.data.Forms._
-      import play.api.data._
-      implicit val req = ctx.body
-      Form(single("lang" -> text.verifying(env.pool contains _))).bindFromRequest.fold(
-        _ => funit,
-        lang => lila.user.UserRepo.setLang(me.id, lang)
-      ) inject Redirect {
-          HTTPRequest referer ctx.req getOrElse routes.Lobby.home.url
+  def select = OpenBody { implicit ctx =>
+    import play.api.data.Forms._
+    import play.api.data._
+    implicit val req = ctx.body
+    Form(single("lang" -> text.verifying(env.pool contains _))).bindFromRequest.fold(
+      _ => notFound,
+      lang => (ctx.me ?? { me => lila.user.UserRepo.setLang(me.id, lang) }) inject Redirect {
+        s"${Env.api.Net.Protocol}${lang}.${Env.api.Net.Domain}" + {
+          HTTPRequest.referer(ctx.req).fold(routes.Lobby.home.url) { str =>
+            new java.net.URL(str).getPath
+          }
         }
+      }
+    )
   }
 
   def contribute = Open { implicit ctx =>

modules/i18n/src/main/I18nRequestHandler.scala

@@ -23,12 +23,8 @@ final class I18nRequestHandler(
   } yield Redirect(redirectUrlLang(req, userLang))
 
   private def redirectUrl(req: RequestHeader) =
-    protocol +
-      I18nDomain(req.domain).withLang(pool preferred req).domain +
-      req.uri
+    redirectUrlLang(req, pool.preferred(req).language)
 
   private def redirectUrlLang(req: RequestHeader, lang: String) =
-    protocol +
-      I18nDomain(req.domain).withLang(lang).domain +
-      req.uri
+    s"$protocol${I18nDomain(req.domain).withLang(lang).domain}${req.uri}"
 }

public/stylesheets/common.css

@@ -1253,6 +1253,7 @@ div.lichess_language {
 .language_links li:last-child {
   width: 50%;
   font-weight: bold;
+  padding-top: 10px;
 }
 #themepicker {
   float: right;