Ref: https://tools.ietf.org/html/rfc7231#section-6.1

Changes:

* 302 Found
* 307 Temporary Redirect

  Do not apply the default ttl, only set a ttl if Cache-Control or Expires are
present.
  Responses with these status codes are not cacheable by default

* 414 Request-URI Too Large

  Cacheable with "heuristic expiration"

https://www.varnish-cache.org/patchwork/patch/251/

bin/varnishd/cache/cache_rfc2616.c

@@ -111,15 +111,18 @@ RFC2616_Ttl(struct busyobj *bo, double now)
 	default:
 		expp->ttl = -1.;
 		break;
+	case 302: /* Moved Temporarily */
+	case 307: /* Temporary Redirect */
+		expp->ttl = -1.;
 	case 200: /* OK */
 	case 203: /* Non-Authoritative Information */
+	case 204: /* No Content */
 	case 300: /* Multiple Choices */
 	case 301: /* Moved Permanently */
-	case 302: /* Moved Temporarily */
-	case 304: /* Not Modified */
-	case 307: /* Temporary Redirect */
-	case 410: /* Gone */
+	case 304: /* Not Modified - handled like 200 */
 	case 404: /* Not Found */
+	case 410: /* Gone */
+	case 414: /* Request-URI Too Large */
 		/*
 		 * First find any relative specification from the backend
 		 * These take precedence according to RFC2616, 13.2.4

bin/varnishtest/tests/b00015.vtc

@@ -32,7 +32,7 @@ varnish v1 -cliok "ban req.url ~ .*"
 
 server s1 {
 	rxreq
-	txresp -status 302
+	txresp -status 301
 } -start
 
 varnish v1 -vcl+backend {
@@ -45,7 +45,7 @@ varnish v1 -vcl+backend {
 client c1 {
 	txreq -url "/"
 	rxresp
-	expect resp.status == 302
+	expect resp.status == 301
 	expect resp.http.X-varnish == "1007"
 } -run
 
@@ -54,7 +54,7 @@ delay .1
 client c1 {
 	txreq -url "/"
 	rxresp
-	expect resp.status == 302
+	expect resp.status == 301
 	expect resp.http.X-varnish == "1010 1008"
 } -run