From 44093066ec5b07be99cfe0d26fa46bdc248a702e Mon Sep 17 00:00:00 2001
From: npeter83 <npeter83+claude@gmail.com>
Date: Mon, 29 Jun 2026 00:48:18 +0200
Subject: [PATCH] fix(messages): don't inherit a stale chat thread across
 account switch
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Switching accounts does location.reload(), which preserves history.state — so the new
account re-mounted the Messages module from the previous account's _sub sub-view, whose
partnerId belongs to the OLD identity (often the new account's own id → an empty
self-thread). Symptom: after switching to the recipient you land on a blank thread and
the just-received message never shows (F5 keeps history.state); only going back to the
list and reopening the real conversation works.

Fix: (1) strip _sub/_ov from history.state before the switch reload so the new account
starts at the module root; (2) guard Messages so a thread view with partnerId === meId
falls back to the conversation list (can't message yourself).
---
 frontend/src/components/Messages.tsx   | 4 +++-
 frontend/src/components/NavSidebar.tsx | 8 ++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/frontend/src/components/Messages.tsx b/frontend/src/components/Messages.tsx
index 0e514be..1ebdc06 100644
--- a/frontend/src/components/Messages.tsx
+++ b/frontend/src/components/Messages.tsx
@@ -22,7 +22,9 @@ export default function Messages({ meId }: { meId: number }) {
   // the module (open() pushes an entry; back() = history.back()).
   const { view, open, back } = useHistorySubview<View>("list");
 
-  if (typeof view === "object") {
+  // Guard against a stale sub-view whose partnerId is the current user's own id (you can't
+  // message yourself). This can be inherited across an account switch — fall back to the list.
+  if (typeof view === "object" && view.partnerId !== meId) {
     return (
       <PageThread
         meId={meId}
diff --git a/frontend/src/components/NavSidebar.tsx b/frontend/src/components/NavSidebar.tsx
index cd23aff..c3ef325 100644
--- a/frontend/src/components/NavSidebar.tsx
+++ b/frontend/src/components/NavSidebar.tsx
@@ -112,6 +112,14 @@ export default function NavSidebar({
   async function switchTo(id: number) {
     try {
       await api.switchAccount(id);
+      // Drop the previous account's in-module sub-view/overlay before the reload (which would
+      // otherwise preserve history.state across the swap). Otherwise the new account lands on a
+      // stale sub-view — e.g. an open chat thread whose partnerId belongs to the OLD identity
+      // (often the new account's own id → an empty self-thread). Start at the module root instead.
+      const st = { ...(window.history.state || {}) };
+      delete st._sub;
+      delete st._ov;
+      window.history.replaceState(st, "");
       location.reload(); // cleanest way to reload all per-user state for the new account
     } catch {
       /* a revoked/removed account — leave the popover open */