Varnish add more slash in URL - varnish

Question

My varnish cache is accelerator mode and it cause adding more slash after URL.
I check with gtmetrix:
Avoid landing page redirects for the following chain of redirected URLs.
https://www.example2.com/
https://www.example2.com//
https://www.example2.com/
and with google pagespeed test:
Reduce server response time
In our test, your server responded in 1.6 seconds. There are many factors that can slow down your server response time.
Here is my config:
vcl 4.0;
backend default {
.host = "localhost";
.port = "8080";
}
acl purger {
"localhost";
"XXX.XXX.XXX.XXX";
}
sub vcl_recv {
if (client.ip != "127.0.0.1" && req.http.host ~ "XXX.com") {
set req.http.x-redir = "https://www.example.com/" + req.url;
return(synth(850, ""));
}
if (client.ip != "127.0.0.1" && req.http.host ~ "YYY.com") {
set req.http.x-redir = "https://www.example2.com/" + req.url;
return(synth(850, ""));
}
if (req.method == "PURGE") {
if (!client.ip ~ purger) {
return(synth(405, "This IP is not allowed to send PURGE requests."));
}
return (purge);
}
if (req.restarts == 0) {
if (req.http.X-Forwarded-For) {
set req.http.X-Forwarded-For = client.ip;
}
}
if (req.http.Authorization || req.method == "POST") {
return (pass);
}
if (req.url ~ "/feed") {
return (pass);
}
set req.http.cookie = regsuball(req.http.cookie, "wp-settings-\d+=[^;]+(; )?", "");
set req.http.cookie = regsuball(req.http.cookie, "wp-settings-time-\d+=[^;]+(; )?", "");
if (req.http.cookie == "") {
unset req.http.cookie;
}
}
sub vcl_synth {
if (resp.status == 850) {
set resp.http.Location = req.http.x-redir;
set resp.status = 302;
return (deliver);
}
}
sub vcl_purge {
set req.method = "GET";
set req.http.X-Purger = "Purged";
return (restart);
}
sub vcl_backend_response {
set beresp.ttl = 24h;
set beresp.grace = 1h;
}
sub vcl_deliver {
if (req.http.X-Purger) {
set resp.http.X-Purger = req.http.X-Purger;
}
}
Somebody know the reason why varnish do that ?

Answer 1

req.url always includes a / at the beginning.
so correct would be:
set req.http.x-redir = "https://www.example2.com" + req.url;
your question does not correspond to the example1/example2 as it includes XXX and YYY
if you can post a less redacted VCL - i may can help you a bit more
you may need a != "/" on req.url before redirecting. as this would result in a //