From 3c703fcb6fa19066a0b2005b7ac143d45c81b190 Mon Sep 17 00:00:00 2001
From: Mnigos <makowskiigor@gmail.com>
Date: Wed, 14 Oct 2026 10:34:54 +0200
Subject: [PATCH] fix(web): a prompt link opened from a thread no longer lands
 in that thread
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ThreadLinkPrompt acted on the app-wide location without checking that it
belonged to its thread. During a pending navigation to /new?prompt=… the
location already showed the next URL while the params still named the old
thread, so the prompt was placed there and stripped from the URL, and the
new-thread route then reported that the link had no prompt.

Return early unless the location's pathname is the thread's own route.
---
 .../components/promptLinks/ThreadLinkPrompt.tsx    |  3 +++
 apps/web/src/threadRoutes.test.ts                  | 14 ++++++++++++++
 apps/web/src/threadRoutes.ts                       |  6 ++++++
 3 files changed, 23 insertions(+)

diff --git a/apps/web/src/components/promptLinks/ThreadLinkPrompt.tsx b/apps/web/src/components/promptLinks/ThreadLinkPrompt.tsx
index 6fae431bb021..1fd33fb23ce0 100644
--- a/apps/web/src/components/promptLinks/ThreadLinkPrompt.tsx
+++ b/apps/web/src/components/promptLinks/ThreadLinkPrompt.tsx
@@ -3,6 +3,7 @@ import { parseThreadLinkPrompt, withoutPromptLinkParams } from "@t3tools/shared/
 import { useLocation, useNavigate } from "@tanstack/react-router";
 import { useEffect } from "react";
 
+import { isThreadRoutePathname } from "../../threadRoutes";
 import { stackedThreadToast, toastManager } from "../ui/toast";
 import { placeLinkedPrompt } from "./linkedPrompt";
 
@@ -24,6 +25,8 @@ export function ThreadLinkPrompt({ threadRef }: { readonly threadRef: ScopedThre
   });
 
   useEffect(() => {
+    // A pending navigation shows the next location while the params still name this thread.
+    if (!isThreadRoutePathname(location.pathname, threadRef)) return;
     if (!new URLSearchParams(location.search).has("prompt")) return;
     if (!handledLinkKeys.has(location.key)) {
       handledLinkKeys.add(location.key);
diff --git a/apps/web/src/threadRoutes.test.ts b/apps/web/src/threadRoutes.test.ts
index 4a9b00a42be6..b89e8dd942eb 100644
--- a/apps/web/src/threadRoutes.test.ts
+++ b/apps/web/src/threadRoutes.test.ts
@@ -6,6 +6,7 @@ import { DraftId } from "./composerDraftStore";
 import {
   buildDraftThreadRouteParams,
   buildThreadRouteParams,
+  isThreadRoutePathname,
   isThreadRouteSnapshotAuthoritative,
   resolveActiveThreadRouteRef,
   resolveThreadRouteRenderState,
@@ -45,6 +46,19 @@ describe("threadRoutes", () => {
     expect(resolveThreadRouteRef({ threadId: "thread-1" })).toBeNull();
   });
 
+  it("matches only the thread's own route pathname", () => {
+    const ref = scopeThreadRef("env-1" as never, ThreadId.make("thread-1"));
+
+    expect(isThreadRoutePathname("/env-1/thread-1", ref)).toBe(true);
+    expect(isThreadRoutePathname("/env-1/thread-1/", ref)).toBe(true);
+    // A pending navigation away from the thread already shows these locations.
+    expect(isThreadRoutePathname("/new", ref)).toBe(false);
+    expect(isThreadRoutePathname("/env-1/thread-2", ref)).toBe(false);
+    expect(isThreadRoutePathname("/env-2/thread-1", ref)).toBe(false);
+    expect(isThreadRoutePathname("/draft/thread-1", ref)).toBe(false);
+    expect(isThreadRoutePathname("/env-1/thread-1/extra", ref)).toBe(false);
+  });
+
   it("builds canonical draft route params from a draft id", () => {
     expect(buildDraftThreadRouteParams(DraftId.make("draft-1"))).toEqual({
       draftId: "draft-1",
diff --git a/apps/web/src/threadRoutes.ts b/apps/web/src/threadRoutes.ts
index 9220141740d3..51a7cd86b6f6 100644
--- a/apps/web/src/threadRoutes.ts
+++ b/apps/web/src/threadRoutes.ts
@@ -52,6 +52,12 @@ export function buildThreadRouteParams(ref: ScopedThreadRef): {
   };
 }
 
+/** Whether a (decoded) location pathname is `ref`'s own thread route, `/$environmentId/$threadId`. */
+export function isThreadRoutePathname(pathname: string, ref: ScopedThreadRef): boolean {
+  const { environmentId, threadId } = buildThreadRouteParams(ref);
+  return pathname.replace(/\/$/, "") === `/${environmentId}/${threadId}`;
+}
+
 export function buildDraftThreadRouteParams(draftId: DraftId): {
   draftId: DraftId;
 } {