From ae42bd5b15c57ecb5445c69b74e5e15f27d89e3d Mon Sep 17 00:00:00 2001
From: Day Dreamer <87640074+HugoXK@users.noreply.github.com>
Date: Tue, 3 Nov 2026 01:43:29 +0800
Subject: [PATCH] fix(client): keep the landing on a session the list knows
 (#2206)
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The landing runs from a 400 ms timer with no click behind it, and the shell's
replaceMain calls sessions.retain, which throws synchronously on an id its
session list does not know (`sessions.retain: unknown session`). landingPart
answered with the roster alone, so an id the list had not listed yet — a cold
load, an archived part the roster still named as current — was handed to
openSession and became the two uncaught errors on load.

With the list in hand only a destination the list knows is returned, in the
same priority as before: a fresh part it has not caught up with falls back to
the chat it replaced, and with nothing known landingPart answers undefined and
landOn records `refused` and leaves the view where it is, instead of clearing
the surface for a navigation that will not happen. A caller that passes no list
keeps the id fallback.

Fixes #2206
---
 .../2206-landing-part-unknown.fixed.md        |  1 +
 core/client.js                                | 15 +++++++++-----
 core/src/client/index.js                      |  5 ++++-
 core/src/client/text.js                       | 18 +++++++++++++----
 core/test/land-on.test.js                     | 15 ++++++++++++++
 docs/subsystems/core-client.md                |  2 +-
 patches/ds-bot/0001-core-fixes.patch          | 20 ++++++++++++++-----
 patches/ds-bot/0003-flybot-api-client.patch   |  7 +++++--
 patches/ds-bot/0008-client-bundle.patch       | 19 +++++++++++-------
 patches/ds-bot/files/test/land-on.test.js     | 15 ++++++++++++++
 10 files changed, 92 insertions(+), 25 deletions(-)
 create mode 100644 changelog.d/2206-landing-part-unknown.fixed.md

diff --git a/changelog.d/2206-landing-part-unknown.fixed.md b/changelog.d/2206-landing-part-unknown.fixed.md
new file mode 100644
index 000000000..b4a87a05f
--- /dev/null
+++ b/changelog.d/2206-landing-part-unknown.fixed.md
@@ -0,0 +1 @@
+The main view no longer hands the shell a conversation its session list does not know, so loading a Bot stops throwing the two uncaught `sessions.retain: unknown session` errors from the landing timer: a part the list has not listed yet falls back to the chat it replaced, and when the list knows none of them the view simply stays where it is ([#2206](https://github.com/ThinkFlowLab/FlyBot/issues/2206), reported in [#1306](https://github.com/ThinkFlowLab/FlyBot/issues/1306)).
diff --git a/core/client.js b/core/client.js
index e4f0eba37..7da4f3072 100644
--- a/core/client.js
+++ b/core/client.js
@@ -2509,12 +2509,16 @@ var HEADER = /^\[(Message from|Reply from|Group chat|Group post from|Bot team se
 var currentPart = (bot) => bot.sessionId ?? bot.id;
 function landingPart(roster, last, mainId, { stay = false, view = "", sessions } = {}) {
   const bot = last ? roster.byId[last.botId] : void 0;
-  if (bot && currentPart(bot) !== last.sessionId) return currentPart(bot);
-  if (bot && stay) return last.sessionId;
   const held = last !== null && last !== void 0 && (stay || view === last.sessionId) && sessions?.byId?.[last.sessionId] !== void 0;
-  if (held) return last.sessionId;
   const main = roster.byId[mainId];
-  return main ? currentPart(main) : mainId;
+  const destinations = [
+    bot && currentPart(bot) !== last.sessionId ? currentPart(bot) : void 0,
+    bot && stay ? last.sessionId : void 0,
+    held ? last.sessionId : void 0,
+    main ? currentPart(main) : mainId
+  ].filter((id) => id !== void 0);
+  if (sessions === void 0) return destinations[0];
+  return destinations.find((id) => sessions.byId?.[id] !== void 0);
 }
 function reminderPrompts(text2) {
   const one = /^reminder_prompt_json: (.*)$/m.exec(text2);
@@ -22427,8 +22431,9 @@ function apply(ctx) {
     landOn: async (id, last, { stay = false, view = "" } = {}) => {
       if (last) await pull().catch(() => {
       });
-      setPlain(false);
       const target = landingPart(roster.getSnapshot(), last, id, { stay, view, sessions: ctx.sessions.list.getSnapshot() });
+      if (target === void 0) return noteNavigation("refused", id, last?.sessionId);
+      setPlain(false);
       noteNavigation("landOn", target, last?.sessionId);
       expected = target;
       ctx.uiWorkspace.openSession(target);
diff --git a/core/src/client/index.js b/core/src/client/index.js
index 8f48d3b1c..b568bc42c 100644
--- a/core/src/client/index.js
+++ b/core/src/client/index.js
@@ -451,8 +451,11 @@ export function apply(ctx) {
     // was archived for a fresh one, the view goes on in the fresh one.
     landOn: async (id, last, { stay = false, view = '' } = {}) => {
       if (last) await pull().catch(() => { /* a stale team list is fixed by the next pull */ })
-      setPlain(false)
       const target = landingPart(roster.getSnapshot(), last, id, { stay, view, sessions: ctx.sessions.list.getSnapshot() })
+      // #1306: no destination the session list knows. The shell would throw, and this call comes from
+      // a 400 ms timer with no click behind it; leaving the view where it is keeps the page quiet.
+      if (target === undefined) return noteNavigation('refused', id, last?.sessionId)
+      setPlain(false)
       noteNavigation('landOn', target, last?.sessionId)
       expected = target
       ctx.uiWorkspace.openSession(target)
diff --git a/core/src/client/text.js b/core/src/client/text.js
index d192ba38c..c4f81a061 100644
--- a/core/src/client/text.js
+++ b/core/src/client/text.js
@@ -84,12 +84,22 @@ export const currentPart = bot => bot.sessionId ?? bot.id
 // and still goes to the Main Bot.
 export function landingPart(roster, last, mainId, { stay = false, view = '', sessions } = {}) {
   const bot = last ? roster.byId[last.botId] : undefined
-  if (bot && currentPart(bot) !== last.sessionId) return currentPart(bot)
-  if (bot && stay) return last.sessionId
+  // In this order: the Bot's current part, the chat the view held, the Main Bot.
   const held = last !== null && last !== undefined && (stay || view === last.sessionId) && sessions?.byId?.[last.sessionId] !== undefined
-  if (held) return last.sessionId
   const main = roster.byId[mainId]
-  return main ? currentPart(main) : mainId
+  const destinations = [
+    bot && currentPart(bot) !== last.sessionId ? currentPart(bot) : undefined,
+    bot && stay ? last.sessionId : undefined,
+    held ? last.sessionId : undefined,
+    main ? currentPart(main) : mainId,
+  ].filter(id => id !== undefined)
+  // A caller that passed no session list gets the id fallback above, as it always did.
+  if (sessions === undefined) return destinations[0]
+  // #1306: the shell throws synchronously on an id its session list does not know
+  // (`sessions.retain: unknown session`), and this landing runs from a timer with no click behind it.
+  // With the list in hand only a destination that list knows is returned: a fresh part it has not
+  // caught up with falls back to the chat it replaced, and nothing known at all is `undefined`.
+  return destinations.find(id => sessions.byId?.[id] !== undefined)
 }
 // The prompts in a due scheduled task's message. DSH frames it for the model: one
 // task as `reminder_prompt_json: "…"`, several as `reminders_json: [{reminder_prompt}]`.
diff --git a/core/test/land-on.test.js b/core/test/land-on.test.js
index 62e482b5c..8008da7da 100644
--- a/core/test/land-on.test.js
+++ b/core/test/land-on.test.js
@@ -73,3 +73,18 @@ test('a navigation with no user activation behind it is noted, with where it wen
     clearClientErrors()
   }
 })
+
+// #1306: the landing runs from a 400 ms timer with no click behind it, and the shell throws
+// synchronously on an id its session list does not know (`sessions.retain: unknown session`) —
+// the two uncaught errors in the report. When the caller passes the list, a destination that
+// list does not know is never returned: a fresh part the list has not caught up with falls back
+// to the chat it replaced, and with nothing known there is no destination at all.
+test('#1306: a destination the session list does not know is never handed to the shell', () => {
+  const pending = { byId: {}, phase: 'pending' }
+  assert.equal(landingPart(roster, null, 'chief', { sessions: pending }), undefined, 'a session list that has not loaded: no destination')
+  assert.equal(landingPart(roster, last, 'chief', { stay: true, sessions: pending }), undefined, 'the held chat is not in the list either')
+  const fresh = { ...friend, sessionId: 'friend-2' }
+  const gone = { byId: { 'chief-2': { id: 'chief-2' } } }
+  assert.equal(landingPart({ byId: { friend: fresh, chief } }, last, 'chief', { stay: true, sessions: gone }), 'chief-2', 'a fresh part the list has not caught up with, the chat it replaced gone: the Main Bot')
+  assert.equal(landingPart({ byId: { friend: fresh, chief } }, last, 'chief', { stay: true, sessions }), 'friend-1', 'the fresh part is unknown, the chat it replaced is known: stay on that chat')
+})
diff --git a/docs/subsystems/core-client.md b/docs/subsystems/core-client.md
index fb53ce491..4c8729699 100644
--- a/docs/subsystems/core-client.md
+++ b/docs/subsystems/core-client.md
@@ -77,7 +77,7 @@ Add a new invariant under the heading it belongs to (or a new heading), not at t
 
 ### Main view landing and navigation trace (#261)
 
-`useLandOnMainBot` (`sidebar.js`) puts an emptied main view back on a Bot. `landingPart` (`text.js`) picks where: a part archived for a fresh one goes on in the fresh part; a view that emptied while its chat is still the Bot's current part (a session list reload, not the user leaving) returns to that same chat; a chat whose Bot the roster no longer lists (a revoked share, a removal) stays put while its session is still in the session list, including a blank chat of that same session, because the session list — not the roster — says whether the conversation exists (#261); a New Session the user opened, or a session archived together with its Bot, goes to the Main Bot. Every `openSession` and `landOn` with no user activation behind it (`navigator.userActivation.isActive === false`) is written to the client diagnostics and the console (`navigation: landOn to … from … with no click (caller stack)`), so a jump a user cannot explain names its caller.
+`useLandOnMainBot` (`sidebar.js`) puts an emptied main view back on a Bot. `landingPart` (`text.js`) picks where: a part archived for a fresh one goes on in the fresh part; a view that emptied while its chat is still the Bot's current part (a session list reload, not the user leaving) returns to that same chat; a chat whose Bot the roster no longer lists (a revoked share, a removal) stays put while its session is still in the session list, including a blank chat of that same session, because the session list — not the roster — says whether the conversation exists (#261); a New Session the user opened, or a session archived together with its Bot, goes to the Main Bot. The session list also decides whether an id may be handed to the shell at all: the shell's `replaceMain` calls `sessions.retain`, which **throws synchronously** on an id the list does not know (`sessions.retain: unknown session`), and the landing runs from a 400 ms timer with no click behind it — so since #2206 a caller that passes the list gets only a destination that list knows, a fresh part it has not listed yet falls back to the chat it replaced, and with nothing known `landingPart` answers `undefined` and `landOn` records `refused` and leaves the view where it is instead of an uncaught error. Every `openSession` and `landOn` with no user activation behind it (`navigator.userActivation.isActive === false`) is written to the client diagnostics and the console (`navigation: landOn to … from … with no click (caller stack)`), so a jump a user cannot explain names its caller.
 
 ### Secrets page scope control (#545)
 
diff --git a/patches/ds-bot/0001-core-fixes.patch b/patches/ds-bot/0001-core-fixes.patch
index 26b1b4d7d..ce414aeec 100644
--- a/patches/ds-bot/0001-core-fixes.patch
+++ b/patches/ds-bot/0001-core-fixes.patch
@@ -2736,7 +2736,7 @@ diff --git a/src/client/text.js b/src/client/text.js
  function clock(ms) {
    return new Date(ms).toLocaleTimeString(dateLocale(), { hour: 'numeric', minute: '2-digit' })
  }
-@@ -48,6 +48,24 @@ export function relativeShort(ms) {
+@@ -48,6 +48,34 @@ export function relativeShort(ms) {
  export const contentText = content => (content ?? []).filter(block => block?.type === 'text').map(block => block.text).join('\n')
  export const HEADER = /^\[(Message from|Reply from|Group chat|Group post from|Bot team setup|Handoff · part|Secret card)[^\]]*\]\n?/
  export const currentPart = bot => bot.sessionId ?? bot.id
@@ -2751,12 +2751,22 @@ diff --git a/src/client/text.js b/src/client/text.js
 +// and still goes to the Main Bot.
 +export function landingPart(roster, last, mainId, { stay = false, view = '', sessions } = {}) {
 +  const bot = last ? roster.byId[last.botId] : undefined
-+  if (bot && currentPart(bot) !== last.sessionId) return currentPart(bot)
-+  if (bot && stay) return last.sessionId
++  // In this order: the Bot's current part, the chat the view held, the Main Bot.
 +  const held = last !== null && last !== undefined && (stay || view === last.sessionId) && sessions?.byId?.[last.sessionId] !== undefined
-+  if (held) return last.sessionId
 +  const main = roster.byId[mainId]
-+  return main ? currentPart(main) : mainId
++  const destinations = [
++    bot && currentPart(bot) !== last.sessionId ? currentPart(bot) : undefined,
++    bot && stay ? last.sessionId : undefined,
++    held ? last.sessionId : undefined,
++    main ? currentPart(main) : mainId,
++  ].filter(id => id !== undefined)
++  // A caller that passed no session list gets the id fallback above, as it always did.
++  if (sessions === undefined) return destinations[0]
++  // #1306: the shell throws synchronously on an id its session list does not know
++  // (`sessions.retain: unknown session`), and this landing runs from a timer with no click behind it.
++  // With the list in hand only a destination that list knows is returned: a fresh part it has not
++  // caught up with falls back to the chat it replaced, and nothing known at all is `undefined`.
++  return destinations.find(id => sessions.byId?.[id] !== undefined)
 +}
  // The prompts in a due scheduled task's message. DSH frames it for the model: one
  // task as `reminder_prompt_json: "…"`, several as `reminders_json: [{reminder_prompt}]`.
diff --git a/patches/ds-bot/0003-flybot-api-client.patch b/patches/ds-bot/0003-flybot-api-client.patch
index a7be22527..1dd439ddc 100644
--- a/patches/ds-bot/0003-flybot-api-client.patch
+++ b/patches/ds-bot/0003-flybot-api-client.patch
@@ -1646,7 +1646,7 @@ diff --git a/src/client/index.js b/src/client/index.js
        // A DSH Agent Session id lands on the plain surface, not the Bot skin.
        if (isAgentSessionId(id)) return actions.openAgentSession(id)
        ui.set(state => (state.newChat || state.exchange || state.menu || state.palette ? { ...state, newChat: null, exchange: null, menu: null, palette: null } : state))
-@@ -409,11 +409,11 @@ export function apply(ctx) {
+@@ -409,11 +409,14 @@ export function apply(ctx) {
      },
      // `last` is the Bot conversation the view held before it cleared: when that part
      // was archived for a fresh one, the view goes on in the fresh one.
@@ -1655,9 +1655,12 @@ diff --git a/src/client/index.js b/src/client/index.js
 -      const bot = last ? roster.getSnapshot().byId[last.botId] : undefined
 +    landOn: async (id, last, { stay = false, view = '' } = {}) => {
 +      if (last) await pull().catch(() => { /* a stale team list is fixed by the next pull */ })
++      const target = landingPart(roster.getSnapshot(), last, id, { stay, view, sessions: ctx.sessions.list.getSnapshot() })
++      // #1306: no destination the session list knows. The shell would throw, and this call comes from
++      // a 400 ms timer with no click behind it; leaving the view where it is keeps the page quiet.
++      if (target === undefined) return noteNavigation('refused', id, last?.sessionId)
        setPlain(false)
 -      const target = bot && currentPart(bot) !== last.sessionId ? currentPart(bot) : partFor(id)
-+      const target = landingPart(roster.getSnapshot(), last, id, { stay, view, sessions: ctx.sessions.list.getSnapshot() })
 +      noteNavigation('landOn', target, last?.sessionId)
        expected = target
        ctx.uiWorkspace.openSession(target)
diff --git a/patches/ds-bot/0008-client-bundle.patch b/patches/ds-bot/0008-client-bundle.patch
index 32d022621..a22782175 100644
--- a/patches/ds-bot/0008-client-bundle.patch
+++ b/patches/ds-bot/0008-client-bundle.patch
@@ -1964,7 +1964,7 @@ diff --git a/client.js b/client.js
  function clock(ms) {
    return new Date(ms).toLocaleTimeString(dateLocale(), { hour: "numeric", minute: "2-digit" });
  }
-@@ -1483,9 +1483,18 @@ function relativeShort(ms) {
+@@ -1483,9 +1483,22 @@ function relativeShort(ms) {
  var contentText = (content) => (content ?? []).filter((block) => block?.type === "text").map((block) => block.text).join("\n");
  var HEADER = /^\[(Message from|Reply from|Group chat|Group post from|Bot team setup|Handoff · part|Secret card)[^\]]*\]\n?/;
  var currentPart = (bot) => bot.sessionId ?? bot.id;
@@ -1973,12 +1973,16 @@ diff --git a/client.js b/client.js
 -  const batch = /^reminders_json: (.*)$/m.exec(text);
 +function landingPart(roster, last, mainId, { stay = false, view = "", sessions } = {}) {
 +  const bot = last ? roster.byId[last.botId] : void 0;
-+  if (bot && currentPart(bot) !== last.sessionId) return currentPart(bot);
-+  if (bot && stay) return last.sessionId;
 +  const held = last !== null && last !== void 0 && (stay || view === last.sessionId) && sessions?.byId?.[last.sessionId] !== void 0;
-+  if (held) return last.sessionId;
 +  const main = roster.byId[mainId];
-+  return main ? currentPart(main) : mainId;
++  const destinations = [
++    bot && currentPart(bot) !== last.sessionId ? currentPart(bot) : void 0,
++    bot && stay ? last.sessionId : void 0,
++    held ? last.sessionId : void 0,
++    main ? currentPart(main) : mainId
++  ].filter((id) => id !== void 0);
++  if (sessions === void 0) return destinations[0];
++  return destinations.find((id) => sessions.byId?.[id] !== void 0);
 +}
 +function reminderPrompts(text2) {
 +  const one = /^reminder_prompt_json: (.*)$/m.exec(text2);
@@ -24834,7 +24838,7 @@ diff --git a/client.js b/client.js
        if (isAgentSessionId(id)) return actions.openAgentSession(id);
        ui2.set((state) => state.newChat || state.exchange || state.menu || state.palette ? { ...state, newChat: null, exchange: null, menu: null, palette: null } : state);
        setPlain(false);
-@@ -13653,12 +13653,12 @@ function apply(ctx) {
+@@ -13653,12 +13653,13 @@ function apply(ctx) {
      },
      // `last` is the Bot conversation the view held before it cleared: when that part
      // was archived for a fresh one, the view goes on in the fresh one.
@@ -24843,9 +24847,10 @@ diff --git a/client.js b/client.js
        if (last) await pull().catch(() => {
        });
 -      const bot = last ? roster.getSnapshot().byId[last.botId] : void 0;
++      const target = landingPart(roster.getSnapshot(), last, id, { stay, view, sessions: ctx.sessions.list.getSnapshot() });
++      if (target === void 0) return noteNavigation("refused", id, last?.sessionId);
        setPlain(false);
 -      const target = bot && currentPart(bot) !== last.sessionId ? currentPart(bot) : partFor(id);
-+      const target = landingPart(roster.getSnapshot(), last, id, { stay, view, sessions: ctx.sessions.list.getSnapshot() });
 +      noteNavigation("landOn", target, last?.sessionId);
        expected = target;
        ctx.uiWorkspace.openSession(target);
diff --git a/patches/ds-bot/files/test/land-on.test.js b/patches/ds-bot/files/test/land-on.test.js
index 62e482b5c..8008da7da 100644
--- a/patches/ds-bot/files/test/land-on.test.js
+++ b/patches/ds-bot/files/test/land-on.test.js
@@ -73,3 +73,18 @@ test('a navigation with no user activation behind it is noted, with where it wen
     clearClientErrors()
   }
 })
+
+// #1306: the landing runs from a 400 ms timer with no click behind it, and the shell throws
+// synchronously on an id its session list does not know (`sessions.retain: unknown session`) —
+// the two uncaught errors in the report. When the caller passes the list, a destination that
+// list does not know is never returned: a fresh part the list has not caught up with falls back
+// to the chat it replaced, and with nothing known there is no destination at all.
+test('#1306: a destination the session list does not know is never handed to the shell', () => {
+  const pending = { byId: {}, phase: 'pending' }
+  assert.equal(landingPart(roster, null, 'chief', { sessions: pending }), undefined, 'a session list that has not loaded: no destination')
+  assert.equal(landingPart(roster, last, 'chief', { stay: true, sessions: pending }), undefined, 'the held chat is not in the list either')
+  const fresh = { ...friend, sessionId: 'friend-2' }
+  const gone = { byId: { 'chief-2': { id: 'chief-2' } } }
+  assert.equal(landingPart({ byId: { friend: fresh, chief } }, last, 'chief', { stay: true, sessions: gone }), 'chief-2', 'a fresh part the list has not caught up with, the chat it replaced gone: the Main Bot')
+  assert.equal(landingPart({ byId: { friend: fresh, chief } }, last, 'chief', { stay: true, sessions }), 'friend-1', 'the fresh part is unknown, the chat it replaced is known: stay on that chat')
+})