fix(email): restore the sender identity when reopening a draft

Reopening a draft reset the composer's From to the default identity. The
edit-draft handler matched the draft's saved From against the active-account
identity list by email only, so two identities sharing an address (a default +
an alias differing by name) collided — the wrong one was picked, or with
cross-account namespaced ids none was.

Add findDraftIdentityId (name+email, normalized, +tag fallback) and match against
the same list the composer renders (the flat cross-account list when multi-
account is on). Wired into both the classic and Pro edit-draft paths. Unit tests
plus the un-pinned 07-drafts integration spec.

app/(main)/[locale]/page.tsx

@@ -61,7 +61,8 @@ import { isFilePreviewable } from "@/lib/file-preview";
 import { appendHtmlSignature, appendPlainTextSignature } from "@/lib/signature-utils";
 import { computeReplyThreadingHeaders } from "@/lib/email-threading";
 import { EML_IMPORT_ACCEPT, expandImportableEmails } from "@/lib/eml-import";
-import { resolveReplyFrom } from "@/lib/reply-identity";
+import { findDraftIdentityId, resolveReplyFrom } from "@/lib/reply-identity";
+import { useProMultiAccountIdentities } from "@/hooks/use-pro-multi-account-identities";
 import { Search, Filter, ChevronDown, X, Paperclip, Star, Mail, MailOpen, RotateCcw, PenSquare, PenLine, CheckSquare, Square, AlertTriangle } from "lucide-react";
 import { ResizeHandle } from "@/components/layout/resize-handle";
 import { Button } from "@/components/ui/button";
@@ -119,6 +120,7 @@ export default function Home() {
   const initialMailLoadClientRef = useRef<object | null>(null);
   const { isAuthenticated, client, logout, checkAuth, switchAccount, activeAccountId, isLoading: authLoading, connectionLost, isRateLimited, rateLimitUntil } = useAuthStore();
   const { identities } = useIdentityStore();
+  const multiAccountIdentities = useProMultiAccountIdentities();
   useIdentitySync();
   const trustedSendersAddressBook = useSettingsStore((state) => state.trustedSendersAddressBook);
   const sendDelaySeconds = useSettingsStore((state) => state.sendDelaySeconds);
@@ -1409,11 +1411,15 @@ export default function Home() {
       ? draft.bodyValues[draftHtmlPart.partId].value
       : undefined;
 
-    // Try to find the identity that matches the draft's from address to preserve it
-    const draftFromEmail = draft.from?.[0]?.email;
-    const matchedIdentity = draftFromEmail
-      ? identities.find(id => id.email === draftFromEmail)
-      : null;
+    // Restore the identity the draft was composed with. Match the saved From
+    // (name + address) against the same list the composer renders — the flat
+    // cross-account list when multi-account is on — so a draft from a non-active
+    // account, or one of two identities sharing an address, is restored rather
+    // than reset to the default.
+    const composerIdentities = multiAccountIdentities.enabled
+      ? multiAccountIdentities.allIdentities
+      : identities;
+    const matchedIdentityId = findDraftIdentityId(composerIdentities, draft.from?.[0]);
 
     // Increment session ID to force the composer to remount with fresh state,
     // even if it was already open (e.g. right-clicking a draft while composing).
@@ -1426,7 +1432,7 @@ export default function Home() {
       body: htmlBody || bodyText,
       showCc: (draft.cc?.length || 0) > 0,
       showBcc: (draft.bcc?.length || 0) > 0,
-      selectedIdentityId: matchedIdentity?.id ?? null,
+      selectedIdentityId: matchedIdentityId,
       subAddressTag: '',
       mode: 'compose',
       draftId: draft.id,

components/pro/pro-email-tab-body.tsx

@@ -7,6 +7,8 @@ import { ErrorBoundary, EmailViewerErrorFallback } from "@/components/error";
 import { useAuthStore } from "@/stores/auth-store";
 import { useEmailStore } from "@/stores/email-store";
 import { useIdentityStore } from "@/stores/identity-store";
+import { useProMultiAccountIdentities } from "@/hooks/use-pro-multi-account-identities";
+import { findDraftIdentityId } from "@/lib/reply-identity";
 import { useSettingsStore } from "@/stores/settings-store";
 import { toast } from "@/stores/toast-store";
 import { useProTabStore, type ProEmailTabData, type ProReplyContext } from "@/stores/pro-tab-store";
@@ -56,6 +58,7 @@ export function ProEmailTabBody({ tabId, data }: ProEmailTabBodyProps) {
   const mailboxes = useEmailStore((s) => s.mailboxes);
   const settingsKeywords = useSettingsStore((s) => s.emailKeywords);
   const identities = useIdentityStore((s) => s.identities);
+  const multiAccountIdentities = useProMultiAccountIdentities();
 
   const closeTab = useProTabStore((s) => s.closeTab);
   const openComposeTab = useProTabStore((s) => s.openComposeTab);
@@ -242,11 +245,12 @@ export function ProEmailTabBody({ tabId, data }: ProEmailTabBodyProps) {
       ? email.bodyValues[draftHtmlPart.partId].value
       : undefined;
 
-    // Preserve the identity that matches the draft's From address.
-    const draftFromEmail = email.from?.[0]?.email;
-    const matchedIdentity = draftFromEmail
-      ? identities.find((id) => id.email === draftFromEmail)
-      : null;
+    // Preserve the identity the draft was composed with — match name + address
+    // against the same list the composer renders (see findDraftIdentityId).
+    const composerIdentities = multiAccountIdentities.enabled
+      ? multiAccountIdentities.allIdentities
+      : identities;
+    const matchedIdentityId = findDraftIdentityId(composerIdentities, email.from?.[0]);
 
     composerSessionIdRef.current += 1;
     openComposeTab({
@@ -261,14 +265,14 @@ export function ProEmailTabBody({ tabId, data }: ProEmailTabBodyProps) {
         body: htmlBody || bodyText,
         showCc: (email.cc?.length || 0) > 0,
         showBcc: (email.bcc?.length || 0) > 0,
-        selectedIdentityId: matchedIdentity?.id ?? null,
+        selectedIdentityId: matchedIdentityId,
         subAddressTag: '',
         mode: 'compose',
         draftId: email.id,
       },
     });
     closeTab(tabId);
-  }, [email, identities, openComposeTab, closeTab, tabId, t]);
+  }, [email, identities, multiAccountIdentities, openComposeTab, closeTab, tabId, t]);
 
   return (
     <div className="flex h-full w-full flex-col bg-background">

integration/tests/07-drafts.spec.ts

@@ -120,12 +120,10 @@ test.describe('Drafts', () => {
     expect((draft.from ?? [])[0]?.name, 'draft From carries the selected identity').toBe('Alice Team');
   });
 
-  // KNOWN BUG (documented via test.fail): a draft composed with a non-default
-  // identity is saved with the right From on the server (see the test above),
-  // but reopening the draft resets the composer's From selector to the default
-  // identity instead of restoring the one the draft was written with. If this
-  // starts passing, the reopen path was fixed — flip this back to a plain test.
-  test.fail('reopening a draft restores the changed sender in the From selector', async ({ page }) => {
+  // Regression: reopening a draft must restore the identity it was written with
+  // (drafts store the From address+name, not an identity id, so the reopen path
+  // matches name+address against the identity list — see findDraftIdentityId).
+  test('reopening a draft restores the changed sender in the From selector', async ({ page }) => {
     const altId = await jmap.ensureIdentity('Alice Team', alice.email);
     const subject = subj('draft-from-reopen');
 

lib/__tests__/reply-identity.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { findComposeIdentityId, findReplyIdentityId, resolveReplyFrom } from '../reply-identity';
+import { findComposeIdentityId, findDraftIdentityId, findReplyIdentityId, resolveReplyFrom } from '../reply-identity';
 import type { Identity } from '../jmap/types';
 
 const identities: Identity[] = [
@@ -17,6 +17,36 @@ const identities: Identity[] = [
   },
 ];
 
+describe('findDraftIdentityId', () => {
+  // Two identities on the SAME address, differing only by display name — the
+  // reopen-draft regression: an email-only match picks the default, not the one
+  // the draft was written with.
+  const sameAddress: Identity[] = [
+    { id: 'default', name: 'Harry Primary', email: 'harry@primary.com', mayDelete: false },
+    { id: 'team', name: 'Harry Team', email: 'harry@primary.com', mayDelete: false },
+  ];
+
+  it('restores the exact identity by name when several share an address', () => {
+    expect(findDraftIdentityId(sameAddress, { name: 'Harry Team', email: 'harry@primary.com' })).toBe('team');
+    expect(findDraftIdentityId(sameAddress, { name: 'Harry Primary', email: 'harry@primary.com' })).toBe('default');
+  });
+
+  it('matches by email (normalized) when the name is absent or unique', () => {
+    expect(findDraftIdentityId(identities, { email: 'HARRY@Secondary.com' })).toBe('secondary');
+    expect(findDraftIdentityId(identities, { name: 'Whatever', email: 'harry@secondary.com' })).toBe('secondary');
+  });
+
+  it('falls back to the +tag-stripped base address', () => {
+    expect(findDraftIdentityId(identities, { email: 'harry+promo@secondary.com' })).toBe('secondary');
+  });
+
+  it('returns null when nothing matches or there is no From', () => {
+    expect(findDraftIdentityId(identities, { email: 'nobody@elsewhere.com' })).toBeNull();
+    expect(findDraftIdentityId(identities, null)).toBeNull();
+    expect(findDraftIdentityId([], { email: 'harry@primary.com' })).toBeNull();
+  });
+});
+
 describe('findReplyIdentityId', () => {
   it('matches the identity that received the original message', () => {
     const selected = findReplyIdentityId(identities, {

lib/reply-identity.ts

@@ -95,6 +95,45 @@ export function findComposeIdentityId(
   return baseIdentity?.id ?? null;
 }
 
+/**
+ * Restore the identity a draft was composed with from its saved From. A draft
+ * stores only the From address+name, not an identityId, so when two identities
+ * share an address (a default + an alias with a different display name) the name
+ * has to disambiguate — an email-only match picks the wrong one. Falls back to
+ * email, then `+tag`-stripped email. Returns null when none match (caller keeps
+ * the default). Pass the same identity list the composer renders (the flat
+ * cross-account list when multi-account is on) so the returned id is usable
+ * there.
+ */
+export function findDraftIdentityId(
+  identities: Identity[],
+  from?: { email?: string | null; name?: string | null } | null,
+): string | null {
+  const email = from?.email?.trim();
+  if (identities.length === 0 || !email) {
+    return null;
+  }
+
+  const wantEmail = normalizeEmailAddress(email);
+  const wantName = (from?.name ?? '').trim();
+
+  const nameAndEmail = identities.find(
+    (i) => normalizeEmailAddress(i.email) === wantEmail && (i.name ?? '').trim() === wantName,
+  );
+  if (nameAndEmail) {
+    return nameAndEmail.id;
+  }
+
+  const exact = identities.find((i) => normalizeEmailAddress(i.email) === wantEmail);
+  if (exact) {
+    return exact.id;
+  }
+
+  const wantBase = normalizeBaseEmailAddress(email);
+  const base = identities.find((i) => normalizeBaseEmailAddress(i.email) === wantBase);
+  return base?.id ?? null;
+}
+
 export interface ReplyFromResolution {
   /** Identity to use for JMAP `identityId` and the SMTP envelope MAIL FROM. */
   identityId: string;