Add header Vary Accept-Language (#4588)

* nginx: add header Vary Accept-Language

solves #3647

* Revert "nginx: add header Vary Accept-Language"

This reverts commit 90dccf53247882ad30904e4c950b745c4e859e01.

* add resp header Vary Accept-Language

solves #3647

* don't add vary header to embed page

1 files changed, 6 insertions, 2 deletions

diff --git a/server/lib/client-html.ts b/server/lib/client-html.ts
index b2948254b..360b4667f 100644
--- a/server/lib/client-html.ts
+++ b/server/lib/client-html.ts
@@ -555,9 +555,13 @@ class ClientHtml {
   }
 }
 
-function sendHTML (html: string, res: express.Response) {
+function sendHTML (html: string, res: express.Response, localizedHTML: boolean = false) {
   res.set('Content-Type', 'text/html; charset=UTF-8')
 
+  if (localizedHTML) {
+    res.set('Vary', 'Accept-Language')
+  }
+
   return res.send(html)
 }
 
@@ -586,5 +590,5 @@ export {
 async function generateHTMLPage (req: express.Request, res: express.Response, paramLang?: string) {
   const html = await ClientHtml.getDefaultHTMLPage(req, res, paramLang)
 
-  return sendHTML(html, res)
+  return sendHTML(html, res, true)
 }