From 21d058e744dd38ef029ed65b2f074401fa65b94d Mon Sep 17 00:00:00 2001
From: Paul Bakaus <paul.bakaus@gmail.com>
Date: Sat, 25 Jul 2026 17:57:29 -0700
Subject: [PATCH] Clear the durable live-session checkpoint on a terminal SSE
 error reply

The documented abort flow in reference/live.md (live-poll.mjs --reply <id>
error "...") reset the browser bar to PICKING but left the localStorage
checkpoint written for the GENERATING phase in place. Every reload then
resurrected a dead session the server no longer knew about, and the page
stayed wedged until the user hand-cleared the impeccable-live* keys in
the console (issue #362, diagnosed by @yourcodekitten).

An agent error reply is terminal for the session it names: when the id
matches the current session, run the same markSessionHandled + cleanup
teardown as 'discarded' (cleanup includes clearSession); when it matches
a stored-but-not-current checkpoint (the error raced a reload), drop that
checkpoint too. Errors that name no session keep the existing UI-only
reset, and the accept-cleanup and steer branches are untouched.

Regression guard added to tests/live-browser-regression.test.mjs.

Prepared with AI assistance (Claude Code), directed by @pbakaus.

Co-Authored-By: Claude Code <noreply@anthropic.com>
---
 skill/scripts/live-browser.js          | 13 +++++++++++++
 tests/live-browser-regression.test.mjs | 25 +++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/skill/scripts/live-browser.js b/skill/scripts/live-browser.js
index 07f09326a..ecfc212c6 100644
--- a/skill/scripts/live-browser.js
+++ b/skill/scripts/live-browser.js
@@ -6499,6 +6499,19 @@
           if (maybeCompleteSteer(msg)) break;
           console.error('[impeccable] Error:', msg.message);
           showToast('Error: ' + msg.message, 5000);
+          // An agent error reply is terminal for the session it names: tear
+          // it down exactly like 'discarded' (cleanup includes clearSession),
+          // or the durable localStorage checkpoint survives and every reload
+          // resurrects a GENERATING bar for a session the server no longer
+          // knows about (issue #362).
+          if (msg.id && msg.id === currentSessionId) {
+            markSessionHandled();
+            cleanup();
+            break;
+          }
+          // A stored-but-not-current checkpoint naming the errored session
+          // (the error raced a reload) must not resurrect either.
+          if (msg.id && loadSession()?.id === msg.id) clearSession();
           hideBar();
           renderEditBadge('hidden');
           setLiveState('PICKING');
diff --git a/tests/live-browser-regression.test.mjs b/tests/live-browser-regression.test.mjs
index 406e1e97e..c092cc7db 100644
--- a/tests/live-browser-regression.test.mjs
+++ b/tests/live-browser-regression.test.mjs
@@ -273,6 +273,31 @@ describe('live-browser.js regression guards', () => {
     );
   });
 
+  it('SSE error reply clears the durable session checkpoint like discarded', () => {
+    // Issue #362: `live-poll.mjs --reply <id> error "..."` is the documented
+    // abort flow in reference/live.md, and an agent error reply is terminal
+    // for the session it names. The 'error' case used to reset only the UI
+    // (hideBar + PICKING) while the localStorage checkpoint written for the
+    // GENERATING phase survived — so every reload resurrected a dead session
+    // the server no longer knew about, until the user hand-cleared the
+    // impeccable-live* keys in the console. The error path must tear down the
+    // named session exactly like 'discarded' does (markSessionHandled +
+    // cleanup, which includes clearSession), and drop a stored-but-not-
+    // current checkpoint that matches the errored id.
+    const errorCase = SOURCE.match(/case 'error':[\s\S]{0,2500}?setLiveState\('PICKING'\);\s*break;/);
+    assert.ok(errorCase, 'expected an SSE case \'error\' handler in live-browser.js');
+    assert.match(
+      errorCase[0],
+      /if \(msg\.id && msg\.id === currentSessionId\) \{[\s\S]{0,160}?markSessionHandled\(\);[\s\S]{0,80}?cleanup\(\);[\s\S]{0,80}?break;/,
+      'an error reply naming the current session must run the same markSessionHandled + cleanup teardown as \'discarded\' so the durable checkpoint is cleared',
+    );
+    assert.match(
+      errorCase[0],
+      /if \(msg\.id && loadSession\(\)\?\.id === msg\.id\) clearSession\(\);/,
+      'an error reply naming a stored-but-not-current session must drop that checkpoint so a reload cannot resurrect it',
+    );
+  });
+
   it('handleServerLost preserves the current recoverable phase', () => {
     assert.doesNotMatch(
       SOURCE,