From d01f51a7d02ab8f5d83bdf8cc466b0a8f711f565 Mon Sep 17 00:00:00 2001
From: Jonathan Sykes <telemagnadon@gmail.com>
Date: Wed, 1 Jul 2026 04:43:33 +0800
Subject: [PATCH] fix: send SKIP_WAITING to waiting SW, not active controller,
 to break reload loop

---
 frontend/app.js | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/frontend/app.js b/frontend/app.js
index 6111142..935176a 100755
--- a/frontend/app.js
+++ b/frontend/app.js
@@ -2796,7 +2796,12 @@ function pollBuildTag() {
 // PWA — service worker registration and update banner (WEB mode only)
 // ============================================================================
 
-function showUpdateBanner() {
+let _updateBannerShown = false;
+function showUpdateBanner(waitingSW) {
+  // Only show the banner once per page load
+  if (_updateBannerShown) return;
+  _updateBannerShown = true;
+
   // Use a persistent, click-to-reload toast instead of the standard 2.2s one
   const t = document.createElement('div');
   t.className = 'toast toast-update';
@@ -2804,13 +2809,15 @@ function showUpdateBanner() {
   const container = $('toastContainer');
   container.appendChild(t);
   t.querySelector('.toast-reload-btn').addEventListener('click', () => {
-    // Tell the waiting SW to skip waiting, then reload once it takes control.
-    if (navigator.serviceWorker.controller) {
-      navigator.serviceWorker.controller.postMessage({ type: 'SKIP_WAITING' });
+    if (waitingSW) {
+      // Signal the *waiting* SW (not the active controller) to take over.
+      // Once it does, controllerchange fires and we reload.
+      waitingSW.postMessage({ type: 'SKIP_WAITING' });
+      navigator.serviceWorker.addEventListener('controllerchange', () => window.location.reload(), { once: true });
+    } else {
+      // No waiting SW (e.g. build-tag or SW_UPDATE_AVAILABLE path) — just reload.
+      window.location.reload();
     }
-    navigator.serviceWorker.addEventListener('controllerchange', () => window.location.reload(), { once: true });
-    // Fallback: reload after a short delay in case controllerchange already fired
-    setTimeout(() => window.location.reload(), 500);
   });
 }
 
@@ -2821,20 +2828,21 @@ async function registerServiceWorker() {
 
     // If a new SW is already waiting (e.g. user refreshed after an update),
     // show the banner right away.
-    if (reg.waiting) { showUpdateBanner(); return; }
+    if (reg.waiting) { showUpdateBanner(reg.waiting); return; }
 
     // Listen for a new SW installing after the page is open.
     reg.addEventListener('updatefound', () => {
       const sw = reg.installing;
       if (!sw) return;
       sw.addEventListener('statechange', () => {
-        if (sw.state === 'installed' && reg.waiting) showUpdateBanner();
+        if (sw.state === 'installed' && reg.waiting) showUpdateBanner(reg.waiting);
       });
     });
 
-    // The SW can also broadcast SW_UPDATE_AVAILABLE on its own activate
+    // The SW can also broadcast SW_UPDATE_AVAILABLE on its own activate.
+    // In this case the new SW is already active, so just reload directly.
     navigator.serviceWorker.addEventListener('message', (e) => {
-      if (e.data && e.data.type === 'SW_UPDATE_AVAILABLE') showUpdateBanner();
+      if (e.data && e.data.type === 'SW_UPDATE_AVAILABLE') showUpdateBanner(null);
     });
 
     // Check for updates in the background (useful for long-lived sessions)