From 1614cab78bf5fa7dc74767207c6a836058e7150c Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Sun, 11 Oct 2026 19:04:02 +0200
Subject: [PATCH] fix: return to the message list after sending a new message
 on a phone

---
 .../mail/__tests__/mobile-send-view.test.tsx  | 105 ++++++++++++++++++
 components/mail/mail-app.tsx                  |   5 +-
 2 files changed, 109 insertions(+), 1 deletion(-)
 create mode 100644 components/mail/__tests__/mobile-send-view.test.tsx

diff --git a/components/mail/__tests__/mobile-send-view.test.tsx b/components/mail/__tests__/mobile-send-view.test.tsx
new file mode 100644
index 000000000..a2ff65a80
--- /dev/null
+++ b/components/mail/__tests__/mobile-send-view.test.tsx
@@ -0,0 +1,105 @@
+import React, { Suspense, lazy } from 'react';
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import type { Mailbox } from '@/lib/jmap/types';
+import { useAuthStore } from '@/stores/auth-store';
+import { useEmailStore } from '@/stores/email-store';
+import { useSettingsStore } from '@/stores/settings-store';
+import { usePluginStore } from '@/stores/plugin-store';
+import { useThemeStore } from '@/stores/theme-store';
+import { DEFAULT_SEARCH_FILTERS } from '@/lib/jmap/search-utils';
+
+// After sending a new message on a phone, the reading pane the composer had
+// taken over stayed on screen, empty, with no way back to the list.
+vi.mock('next/dynamic', () => ({ default: (load: () => Promise<React.ComponentType<Record<string, unknown>>>) => {
+  const Component = lazy(async () => ({ default: await load() }));
+  return function Dynamic(props: Record<string, unknown>) {
+    return <Suspense fallback={null}><Component {...props} /></Suspense>;
+  };
+} }));
+vi.mock('@/components/email/email-composer', () => ({
+  EmailComposer: ({ onSend }: { onSend?: (data: unknown) => Promise<void> }) => (
+    <button onClick={() => void onSend?.({ to: ['bob@example.com'], cc: [], bcc: [], subject: 'Hi', body: 'Hello' })}>
+      stub send
+    </button>
+  ),
+}));
+vi.mock('@/components/layout/sidebar', () => ({ Sidebar: () => null }));
+vi.mock('@/components/layout/navigation-rail', () => ({ NavigationRail: () => null }));
+vi.mock('@/components/layout/calendar-event-notification-toaster', () => ({ CalendarEventNotificationToaster: () => null }));
+vi.mock('@/components/layout/share-notification-toaster', () => ({ ShareNotificationToaster: () => null }));
+vi.mock('@/components/layout/mobile-header', () => ({ MobileHeader: () => null }));
+vi.mock('@/components/email/message-list-tabs', () => ({ MessageListTabs: () => null }));
+vi.mock('@/components/search/search-box', () => ({ SearchBox: () => null }));
+vi.mock('@/components/tour/tour-provider', () => ({ useTour: () => ({ activeTour: null, registerStep: vi.fn() }) }));
+vi.mock('@/components/plugins/plugin-slot', () => ({ PluginSlot: () => null }));
+vi.mock('@/hooks/use-plugin-slot-offers', () => ({ usePluginSlotOffers: () => [] }));
+vi.mock('@/hooks/use-config', () => ({ useConfig: () => ({ appName: 'Mail' }) }));
+vi.mock('@/hooks/use-identity-sync', () => ({ useIdentitySync: () => {} }));
+vi.mock('@/hooks/use-pro-multi-account-identities', () => ({ useProMultiAccountIdentities: () => [] }));
+vi.mock('@/hooks/use-pro-multi-account-mailboxes', () => ({ useProMultiAccountMailboxes: () => {} }));
+vi.mock('@/hooks/use-wopi-status', () => ({ useWopiStatus: () => null, canWopiOpen: () => false }));
+vi.mock('@/hooks/use-browser-navigation', () => ({ useBrowserNavigation: () => {} }));
+vi.mock('@/hooks/use-media-query', () => ({
+  useDeviceDetection: () => ({ isMobile: true, isTablet: false, isDesktop: false }),
+  useMediaQuery: () => false,
+  useIsDesktop: () => false,
+}));
+vi.mock('@/lib/push-bindings', () => ({ reconcilePushBindings: () => {}, releasePushBindings: () => {} }));
+vi.mock('@/components/email/email-list', () => ({ EmailList: () => <div>message list</div> }));
+
+const { MailApp } = await import('../mail-app');
+
+const inbox = { id: 'inbox', name: 'Inbox', role: 'inbox' } as Mailbox;
+const sendEmail = vi.fn();
+
+beforeEach(() => {
+  vi.stubGlobal('fetch', vi.fn().mockRejectedValue(new Error('Unexpected network request')));
+  vi.stubGlobal('ResizeObserver', class { observe() {} unobserve() {} disconnect() {} });
+  usePluginStore.setState({ initializePlugins: vi.fn().mockResolvedValue(undefined) });
+  useThemeStore.setState({ syncServerThemes: vi.fn().mockResolvedValue(undefined) });
+  const client = {
+    getAccountId: () => 'acc', getUsername: () => 'me@example.com',
+    getSieveAccountId: () => null, hasDelayedSend: () => false, getSession: () => null,
+  };
+  useAuthStore.setState({
+    isAuthenticated: true, isLoading: false, client: client as never, activeAccountId: 'login', identities: [],
+    getClientForAccount: () => client as never,
+    getAllConnectedClients: () => new Map([['login', client]]) as never,
+  });
+  useSettingsStore.setState({ enableUnifiedMailbox: false, mailLayout: 'split', sendDelaySeconds: 0 } as never);
+  sendEmail.mockReset().mockResolvedValue({});
+  useEmailStore.setState({
+    emails: [], selectedEmail: null, selectedMailbox: inbox.id, mailboxes: [inbox],
+    viewingAccountId: null, accountMailboxes: {}, isUnifiedView: false, unifiedRole: null,
+    isScheduledView: false, isLoadingEmail: false, isLoading: false, searchQuery: '',
+    searchFilters: { ...DEFAULT_SEARCH_FILTERS }, searchMailboxId: '', selectedKeyword: null,
+    selectedEmailKeys: new Set(),
+    fetchMailboxes: vi.fn().mockResolvedValue(undefined), fetchEmails: vi.fn().mockResolvedValue(undefined),
+    fetchQuota: vi.fn().mockResolvedValue(undefined), fetchTagCounts: vi.fn().mockResolvedValue(undefined),
+    refreshScheduledMetadata: vi.fn().mockResolvedValue(undefined),
+    sendEmail,
+  } as never);
+});
+afterEach(() => {
+  vi.restoreAllMocks();
+  vi.unstubAllGlobals();
+});
+
+/** On a phone only one of list and reading pane shows; the other gets max-md:hidden. */
+const listHidden = () => screen.getByText('message list').closest('.max-md\\:hidden') !== null;
+
+describe('sending from a phone', () => {
+  it('goes back to the message list after sending a new message', async () => {
+    render(<MailApp />);
+    fireEvent.click(screen.getByRole('button', { name: 'sidebar.compose' }));
+    await screen.findByText('stub send', {}, { timeout: 5000 });
+    expect(listHidden()).toBe(true);
+
+    fireEvent.click(screen.getByText('stub send'));
+
+    await waitFor(() => expect(sendEmail).toHaveBeenCalled());
+    await waitFor(() => expect(screen.queryByText('stub send')).not.toBeInTheDocument());
+    expect(listHidden()).toBe(false);
+  });
+});
diff --git a/components/mail/mail-app.tsx b/components/mail/mail-app.tsx
index c337be6be..87b74ccbb 100644
--- a/components/mail/mail-app.tsx
+++ b/components/mail/mail-app.tsx
@@ -1886,8 +1886,10 @@ export function MailApp({ linkSegments: routeSegments }: MailAppProps = {}) {
       // selection like a delete does.
       if (selectedEmail && (selectedEmail.id === data.draftId || selectedEmail.id === pendingDraft?.draftId)) {
         selectEmail(null);
-        if (isMobile) setActiveView('list');
       }
+      // On a phone the composer takes over the reading pane. With no message
+      // open behind it, that pane is empty and has no way back to the list.
+      if (isMobile && !useEmailStore.getState().selectedEmail) setActiveView('list');
       if (result.filingError) {
         // The mail went out, but a post-send step (filing to Sent /
         // removing the old draft) was rejected - warn instead of staying
@@ -3815,6 +3817,7 @@ export function MailApp({ linkSegments: routeSegments }: MailAppProps = {}) {
           }
           setShowComposer(false);
           setPendingDraft(null);
+          if (isMobile && !useEmailStore.getState().selectedEmail) setActiveView('list');
         }}
         onClose={() => {
           setShowComposer(false);