From 07ac27e07bf7501ae6ec0c29d87203803ac29381 Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Fri, 27 Oct 2023 21:09:49 -0400
Subject: [PATCH] Give precedence to `Last modified:` field when evaluating
 "age" if lists

Available network information is not very reliable and should be
used only when `Last modified:` is not available.
---
 src/js/assets.js | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/js/assets.js b/src/js/assets.js
index e07d1c3aa..73fec016c 100644
--- a/src/js/assets.js
+++ b/src/js/assets.js
@@ -56,11 +56,13 @@ const resourceTimeFromXhr = xhr => {
         // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Age
         // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Date
         let networkTime = 0;
-        const age = parseInt(xhr.getResponseHeader('Age'), 10);
-        if ( isNaN(age) === false ) {
-            const time = (new Date(xhr.getResponseHeader('Date'))).getTime();
-            if ( isNaN(time) === false ) {
-                networkTime = time - age * 1000;
+        if ( assetTime === 0 ) {
+            const age = parseInt(xhr.getResponseHeader('Age'), 10);
+            if ( isNaN(age) === false ) {
+                const time = (new Date(xhr.getResponseHeader('Date'))).getTime();
+                if ( isNaN(time) === false ) {
+                    networkTime = time - age * 1000;
+                }
             }
         }
         return Math.max(assetTime, networkTime, 0);