fix(web-shell): report intended workspace to host when starting a new chat

packages/web-shell/client/App.test.tsx

@@ -3532,6 +3532,44 @@ describe('App session callbacks', () => {
     );
   });
 
+  it('reports the selected workspace, not the stale connection workspace, when no session is active', async () => {
+    // A cleared session leaves connection.workspaceCwd pointing at the old
+    // workspace (here: a secondary with a running task). Starting a new chat
+    // in the primary must report the primary, not route the host back to the
+    // stale workspace.
+    mockConnection.sessionId = undefined;
+    mockConnection.workspaceCwd = '/work/secondary';
+    mockWorkspace.capabilities = {
+      workspaces: [
+        { id: 'primary', cwd: '/workspace', primary: true, trusted: true },
+        {
+          id: 'secondary',
+          cwd: '/work/secondary',
+          primary: false,
+          trusted: true,
+        },
+      ],
+    };
+    const onSessionIdChange = vi.fn();
+
+    renderApp({
+      onSessionIdChange,
+      initialSelectedWorkspaceCwd: '/workspace',
+    });
+    await flush();
+
+    expect(onSessionIdChange).toHaveBeenCalledWith(
+      undefined,
+      undefined,
+      '/workspace',
+    );
+    expect(onSessionIdChange).not.toHaveBeenCalledWith(
+      undefined,
+      'secondary',
+      '/work/secondary',
+    );
+  });
+
   it('creates scratch once, accepts refreshed capabilities, and opens a fresh chat', async () => {
     mockWorkspace.capabilities = {
       features: [

packages/web-shell/client/App.tsx

@@ -4619,8 +4619,16 @@ export function App({
       lastNotifiedWorkspaceCwdRef.current = undefined;
       return;
     }
+    // With no active session (deferred or just cleared) the connection's
+    // workspaceCwd is a leftover from the previous session — routing the host
+    // by it would send a "new chat in workspace A" back to the old workspace
+    // (e.g. one with a running task). The workspace picked for the next
+    // session is the source of truth in that state.
+    const reportedWorkspaceCwd = connection.sessionId
+      ? connection.workspaceCwd
+      : (selectedWorkspaceCwd ?? connection.workspaceCwd);
     const activeWorkspace = workspaces.find(
-      (entry) => entry.cwd === connection.workspaceCwd,
+      (entry) => entry.cwd === reportedWorkspaceCwd,
     );
     if (connection.sessionId && !workspace.capabilities) return;
     const workspaceId =
@@ -4630,23 +4638,24 @@ export function App({
     if (
       lastNotifiedSessionIdRef.current === connection.sessionId &&
       lastNotifiedWorkspaceIdRef.current === workspaceId &&
-      lastNotifiedWorkspaceCwdRef.current === connection.workspaceCwd
+      lastNotifiedWorkspaceCwdRef.current === reportedWorkspaceCwd
     ) {
       return;
     }
     lastNotifiedSessionIdRef.current = connection.sessionId;
     lastNotifiedWorkspaceIdRef.current = workspaceId;
-    lastNotifiedWorkspaceCwdRef.current = connection.workspaceCwd;
+    lastNotifiedWorkspaceCwdRef.current = reportedWorkspaceCwd;
     onSessionIdChange?.(
       connection.sessionId,
       workspaceId,
-      connection.workspaceCwd,
+      reportedWorkspaceCwd,
     );
   }, [
     connection.missingSession,
     connection.sessionId,
     connection.workspaceCwd,
     onSessionIdChange,
+    selectedWorkspaceCwd,
     workspace.capabilities,
     workspaces,
   ]);