fix: do not propagate well-known port number for xds portRedirect

internal/xds/translator/route.go

@@ -345,7 +345,9 @@ func buildXdsRedirectAction(httpRoute *ir.HTTPRoute) *routev3.RedirectAction {
 	if redirection.Hostname != nil {
 		routeAction.HostRedirect = *redirection.Hostname
 	}
-	if redirection.Port != nil {
+	// Ignore the redirect port if it is a well-known port number, in order to
+	// prevent the port be added in the response's location header.
+	if redirection.Port != nil && *redirection.Port != 80 && *redirection.Port != 443 {
 		routeAction.PortRedirect = *redirection.Port
 	}
 	if redirection.StatusCode != nil {

internal/xds/translator/testdata/in/xds-ir/http-route-redirect.yaml

@@ -50,3 +50,32 @@ http:
     redirect:
       path:
         prefixMatchReplace: /
+  - name: "redirect-route-4"
+    hostname: "*"
+    destination:
+      name: "redirect-route-dest"
+      settings:
+      - endpoints:
+        - host: "1.2.3.4"
+          port: 50000
+    redirect:
+      scheme: https
+      statusCode: 302
+      hostname: "redirected.com"
+      path:
+        prefixMatchReplace: /redirected
+  - name: "redirect-route-5"
+    hostname: "*"
+    destination:
+      name: "redirect-route-dest"
+      settings:
+      - endpoints:
+        - host: "1.2.3.4"
+          port: 50000
+    redirect:
+      scheme: https
+      statusCode: 302
+      port: 443
+      hostname: "redirected.com"
+      path:
+        prefixMatchReplace: /redirected

internal/xds/translator/testdata/out/xds-ir/http-route-redirect.routes.yaml

@@ -30,3 +30,19 @@
           pattern:
             regex: ^/redirect/\/*
           substitution: /
+    - match:
+        prefix: /
+      name: redirect-route-4
+      redirect:
+        hostRedirect: redirected.com
+        prefixRewrite: /redirected
+        responseCode: FOUND
+        schemeRedirect: https
+    - match:
+        prefix: /
+      name: redirect-route-5
+      redirect:
+        hostRedirect: redirected.com
+        prefixRewrite: /redirected
+        responseCode: FOUND
+        schemeRedirect: https