From 29b33eb46cdd007c18f2c4a462844f317ae5b3be Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Mon, 19 Oct 2026 01:32:30 +0200
Subject: [PATCH] fix: show attachment names without directional override
 characters

---
 components/email/attachment-chips.tsx |  5 +++--
 components/email/email-viewer.tsx     |  5 ++++-
 lib/__tests__/bidi.test.ts            | 15 +++++++++++++++
 lib/bidi.ts                           | 12 ++++++++++++
 4 files changed, 34 insertions(+), 3 deletions(-)
 create mode 100644 lib/__tests__/bidi.test.ts
 create mode 100644 lib/bidi.ts

diff --git a/components/email/attachment-chips.tsx b/components/email/attachment-chips.tsx
index 9aa2a6f8b..4ced28825 100644
--- a/components/email/attachment-chips.tsx
+++ b/components/email/attachment-chips.tsx
@@ -3,6 +3,7 @@
 import { useEffect, useState, type ReactNode } from "react";
 import { FileText, FileSpreadsheet, FileImage, FileArchive, File as FileIcon } from "@/components/icons";
 import { cn } from "@/lib/utils";
+import { stripBidiControls } from "@/lib/bidi";
 import type { Attachment, Email } from "@/lib/jmap/types";
 import type { LoadListAttachments } from "@/lib/list-attachments";
 
@@ -78,11 +79,11 @@ export function AttachmentChips({ attachments, onOpen, max = 2, leading, classNa
             // The row itself opens the message; a chip must not do both.
             onClick={(e) => { e.stopPropagation(); onOpen(a); }}
             onDoubleClick={(e) => e.stopPropagation()}
-            title={a.name}
+            title={stripBidiControls(a.name ?? "")}
             className={cn(CHIP_BOX_CLASS, "max-w-[12rem] bg-background/60 text-foreground/80 hover:bg-muted hover:text-foreground")}
           >
             <Icon className={cn(CHIP_ICON_CLASS, iconClass)} />
-            <span className="truncate">{shortName(a.name ?? "")}</span>
+            <span className="truncate">{shortName(stripBidiControls(a.name ?? ""))}</span>
           </button>
         );
       })}
diff --git a/components/email/email-viewer.tsx b/components/email/email-viewer.tsx
index 7ed5fd726..d179d93eb 100644
--- a/components/email/email-viewer.tsx
+++ b/components/email/email-viewer.tsx
@@ -11,6 +11,7 @@ import { collapsePlainTextQuotes, setupQuoteCollapse } from "@/lib/quote-collaps
 import { DARK_PENDING_CLASS, applyEmailDarkMode, emailColorScheme, emailDarkModeCss, emailHasNativeDarkMode as htmlHasNativeDarkMode, resolveColorSchemeMedia } from "@/lib/email-dark-mode";
 import { fitEmailBodyWidth } from "@/lib/email-fit-width";
 import { hasFullBleedCanvas } from "@/lib/email-full-bleed";
+import { stripBidiControls } from "@/lib/bidi";
 import { withBasePath } from "@/lib/browser-navigation";
 import { buildContactsPath, buildMailPath } from "@/lib/deep-links";
 import { useCopyLink } from "@/hooks/use-copy-link";
@@ -269,7 +270,9 @@ const MIME_TYPE_LABELS: Record<string, string> = {
 };
 
 const getAttachmentDisplayName = (name: string | null | undefined, mimeType?: string): string => {
-  if (name) return name;
+  // Without directional overrides, which would show `report‮fdp.exe`
+  // as `reportexe.pdf` (the download name is cleaned separately).
+  if (name) return stripBidiControls(name);
   if (mimeType) {
     const label = MIME_TYPE_LABELS[mimeType.toLowerCase()];
     if (label) return label;
diff --git a/lib/__tests__/bidi.test.ts b/lib/__tests__/bidi.test.ts
new file mode 100644
index 000000000..25837fe89
--- /dev/null
+++ b/lib/__tests__/bidi.test.ts
@@ -0,0 +1,15 @@
+import { describe, expect, it } from 'vitest';
+import { stripBidiControls } from '@/lib/bidi';
+
+describe('stripBidiControls', () => {
+  it('removes the characters that reorder what the reader sees', () => {
+    // An RTL override makes `report‮fdp.exe` read as `reportexe.pdf`.
+    expect(stripBidiControls('report‮fdp.exe')).toBe('reportfdp.exe');
+    expect(stripBidiControls('⁦a⁩‎b‏‪‫‬‭')).toBe('ab');
+  });
+
+  it('leaves ordinary text, including right-to-left scripts, alone', () => {
+    expect(stripBidiControls('Rechnung März.pdf')).toBe('Rechnung März.pdf');
+    expect(stripBidiControls('تقرير.pdf')).toBe('تقرير.pdf');
+  });
+});
diff --git a/lib/bidi.ts b/lib/bidi.ts
new file mode 100644
index 000000000..1aa5ead27
--- /dev/null
+++ b/lib/bidi.ts
@@ -0,0 +1,12 @@
+/**
+ * Unicode directional formatting characters: the explicit embeddings,
+ * overrides and isolates (U+202A-202E, U+2066-2069) and the LRM/RLM marks.
+ * In a sender-controlled name they reorder what the reader sees, so
+ * `report‮fdp.exe` shows as `reportexe.pdf`.
+ */
+const BIDI_CONTROLS = /[‎‏‪-‮⁦-⁩]/g;
+
+/** `text` without directional formatting characters, for display. */
+export function stripBidiControls(text: string): string {
+  return text.replace(BIDI_CONTROLS, '');
+}