ENGCOM-7765: [vcl] don't set TTL to 0 #28927

Author: gabrieldagama

app/code/Magento/PageCache/etc/varnish4.vcl

@@ -159,7 +159,7 @@ sub vcl_backend_response {
 
     # cache only successfully responses and 404s
     if (beresp.status != 200 && beresp.status != 404) {
-        set beresp.ttl = 0s;
+        set beresp.ttl = 120s;
         set beresp.uncacheable = true;
         return (deliver);
     } elsif (beresp.http.Cache-Control ~ "private") {

app/code/Magento/PageCache/etc/varnish5.vcl

@@ -159,11 +159,9 @@ sub vcl_backend_response {
     }
 
     # cache only successfully responses and 404s
-    if (beresp.status != 200 && beresp.status != 404) {
-        set beresp.ttl = 0s;
-        set beresp.uncacheable = true;
-        return (deliver);
-    } elsif (beresp.http.Cache-Control ~ "private") {
+    if (beresp.status != 200 &&
+            beresp.status != 404 &&
+            beresp.http.Cache-Control ~ "private") {
         set beresp.uncacheable = true;
         set beresp.ttl = 86400s;
         return (deliver);

app/code/Magento/PageCache/etc/varnish6.vcl

@@ -162,12 +162,10 @@ sub vcl_backend_response {
         set beresp.http.X-Magento-Cache-Control = beresp.http.Cache-Control;
     }
 
-    # cache only successfully responses and 404s
-    if (beresp.status != 200 && beresp.status != 404) {
-        set beresp.ttl = 0s;
-        set beresp.uncacheable = true;
-        return (deliver);
-    } elsif (beresp.http.Cache-Control ~ "private") {
+    # cache only successfully responses and 404s that are not marked as private
+    if (beresp.status != 200 &&
+            beresp.status != 404 &&
+            beresp.http.Cache-Control ~ "private") {
         set beresp.uncacheable = true;
         set beresp.ttl = 86400s;
         return (deliver);