From 1f0169d1264575e0ee27e56b150b59071edb0c78 Mon Sep 17 00:00:00 2001
From: Paul Bakaus <paul.bakaus@gmail.com>
Date: Fri, 14 Aug 2026 00:01:21 -0400
Subject: [PATCH] Clear the render clock when a poll generation goes stale

Follow-up to the generation stamp: both probe callbacks returned on a stale
generation without clearing the elapsed-time interval. tryLoad clears it on
re-entry, but a probe that finishes stale schedules no re-entry, so flipping
back while one was in flight left the interval ticking for the rest of the
page's life. Both exits now clear it, which is what the isConnected guard above
them already did.

Written with AI assistance (Claude Code).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 skill/scripts/serve-question.mjs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/skill/scripts/serve-question.mjs b/skill/scripts/serve-question.mjs
index ca134504a..4e80b0027 100644
--- a/skill/scripts/serve-question.mjs
+++ b/skill/scripts/serve-question.mjs
@@ -1076,7 +1076,11 @@ ${buildPath?.toggle ? `<div id="bp-confirm" role="dialog" aria-modal="true" aria
       if (!m.isConnected || !m.classList.contains('comp-pending') || !current()) { clearInterval(tick); return; }
       const probe = new Image();
       probe.onload = () => {
-        if (!current()) return;
+        // A stale generation also ends this run's clock. tryLoad clears it on
+        // re-entry, and an in-flight probe that finishes stale schedules no
+        // re-entry, so returning without clearing ran the interval for the rest
+        // of the page's life.
+        if (!current()) { clearInterval(tick); return; }
         landTracker.last = Date.now();
         const target = m.querySelector('img.comp') || img;
         target.src = probe.src;
@@ -1084,7 +1088,7 @@ ${buildPath?.toggle ? `<div id="bp-confirm" role="dialog" aria-modal="true" aria
         settle();
       };
       probe.onerror = () => {
-        if (!current()) return;
+        if (!current()) { clearInterval(tick); return; }
         const quiet = Date.now() - landTracker.last > 240000;
         if (Date.now() - started > 240000 && quiet && fallback()) return;
         setTimeout(tryLoad, m.classList.contains('stand-in') ? 5000 : 2500);