static/js/update: Handle no cache

1 files changed, 3 insertions, 3 deletions

diff --git a/static/js/update.ts b/static/js/update.ts
index 2b96751..d7fda45 100644
--- a/static/js/update.ts
+++ b/static/js/update.ts
@@ -17,11 +17,11 @@
     const url = self.location.href.split("#")[0].split("?")[0];
     check(url, "HEAD", function (request) {
       const local = document.querySelector('meta[name="last-modified"]').content;
-      const remote = request.getResponseHeader("last-modified") || local;
+      const remote = request.getResponseHeader("last-modified") || '';
       const modified = Date.parse(document.lastModified) !== Date.parse(remote);
-      const drift = Date.parse(remote) - Date.parse(local);
+      const drift = Date.parse(remote || local) - Date.parse(local);
 
-      if (modified) {
+      if (remote && modified) {
         const indicator = document.querySelector("a[data-update]");
         check(url, "GET");
         indicator.href = url;