.unipi/docs/fix/2026-06-04-favorite-other-language-post-redirect-fix.md

@@ -0,0 +1,43 @@
+---
+title: "Favorite Other-Language Post Redirect — Quick Fix"
+type: quick-fix
+date: 2026-06-04
+---
+
+# Favorite Other-Language Post Redirect — Quick Fix
+
+## Bug
+
+When the user is on a UI language (e.g. Chinese) and clicks a favorited post that does not have a translation in that language, the post page silently redirected to `/browse` and the user could not see the post.
+
+## Root Cause
+
+`src/pages/PostRedirect/index.tsx` requested `GET /api/posts/{id}?lang=<ui-lang>`. The backend returns `404` when the post has no translation in the requested language. The redirect's `.catch` silently sent the user to `/browse`, hiding the post entirely.
+
+## Fix
+
+`PostRedirect` now retries without the `lang` parameter on failure. If the post exists in any language, the user is taken to the post anyway, and a toast tells them the post is shown in its original language because the selected language is unavailable. If the retry also fails (post truly missing), behavior is unchanged: redirect to `/browse`.
+
+A new i18n key `postShownInOriginalLanguage` was added in all 7 locales.
+
+### Files Modified
+
+- `src/pages/PostRedirect/index.tsx` — added language fallback fetch, toast notice.
+- `src/locales/zh-CN.ts` — added `postShownInOriginalLanguage`.
+- `src/locales/en.ts` — added `postShownInOriginalLanguage`.
+- `src/locales/ja.ts` — added `postShownInOriginalLanguage`.
+- `src/locales/ko.ts` — added `postShownInOriginalLanguage`.
+- `src/locales/vi.ts` — added `postShownInOriginalLanguage`.
+- `src/locales/id.ts` — added `postShownInOriginalLanguage`.
+- `src/locales/ms.ts` — added `postShownInOriginalLanguage`.
+
+## Verification
+
+- `npx tsc --noEmit`
+- `npm run format:check`
+- `npm test` (13 files, 49 tests)
+- Staging curl confirmed: `GET /api/posts/{id}?lang=en` returns `404` for a Chinese-only post, while `GET /api/posts/{id}` returns `200` with the post in its source language.
+
+## Notes
+
+No deploy was performed.

src/locales/en.ts

@@ -166,6 +166,8 @@ export const enDict: Dict = {
   favoritesSortHot: "Hot resources",
   favoritesSearchPlaceholder: "Search your favorites",
   favoritesUnavailable: "Unavailable",
+  postShownInOriginalLanguage:
+    "This post is not available in your selected language. Showing the original.",
   favoritesClearFilters: "Clear filters",
   favorites: "My Favorites",
   favoritesComingSoon: "Coming Soon",

src/locales/id.ts

@@ -166,6 +166,8 @@ export const idDict: Dict = {
   favoritesSortHot: "Sumber populer",
   favoritesSearchPlaceholder: "Cari favorit Anda",
   favoritesUnavailable: "Tidak tersedia",
+  postShownInOriginalLanguage:
+    "Postingan ini tidak tersedia dalam bahasa yang Anda pilih. Menampilkan bahasa aslinya.",
   favoritesClearFilters: "Hapus filter",
   favorites: "Favorit Saya",
   favoritesComingSoon: "Segera Hadir",

src/locales/ja.ts

@@ -166,6 +166,8 @@ export const jaDict: Dict = {
   favoritesSortHot: "人気資料",
   favoritesSearchPlaceholder: "お気に入りを検索",
   favoritesUnavailable: "利用不可",
+  postShownInOriginalLanguage:
+    "この投稿は選択した言語で提供されていないため、原語で表示します。",
   favoritesClearFilters: "フィルターをクリア",
   favorites: "お気に入り",
   favoritesComingSoon: "近日公開",

src/locales/ko.ts

@@ -164,6 +164,8 @@ export const koDict: Dict = {
   favoritesSortHot: "인기 자료",
   favoritesSearchPlaceholder: "내 즐겨찾기 검색",
   favoritesUnavailable: "사용 불가",
+  postShownInOriginalLanguage:
+    "이 게시물은 선택하신 언어로 제공되지 않아 원본 언어로 표시됩니다.",
   favoritesClearFilters: "필터 지우기",
   favorites: "내 즐겨찾기",
   favoritesComingSoon: "출시 예정",

src/locales/ms.ts

@@ -164,6 +164,8 @@ export const msDict: Dict = {
   favoritesSortHot: "Sumber popular",
   favoritesSearchPlaceholder: "Cari kegemaran anda",
   favoritesUnavailable: "Tidak tersedia",
+  postShownInOriginalLanguage:
+    "Pos ini tidak tersedia dalam bahasa pilihan anda. Memaparkan bahasa asal.",
   favoritesClearFilters: "Kosongkan penapis",
   favorites: "Kegemaran Saya",
   favoritesComingSoon: "Akan Hadir",

src/locales/vi.ts

@@ -163,6 +163,8 @@ export const viDict: Dict = {
   favoritesSortHot: "Tài nguyên hot",
   favoritesSearchPlaceholder: "Tìm trong yêu thích",
   favoritesUnavailable: "Không khả dụng",
+  postShownInOriginalLanguage:
+    "Bài đăng này không có trong ngôn ngữ bạn chọn. Đang hiển thị bằng ngôn ngữ gốc.",
   favoritesClearFilters: "Xóa bộ lọc",
   favorites: "Yêu thích của tôi",
   favoritesComingSoon: "Sắp ra mắt",

src/locales/zh-CN.ts

@@ -159,6 +159,7 @@ export const zhDict: Dict = {
   favoritesSortHot: "热门资料",
   favoritesSearchPlaceholder: "搜索我的收藏",
   favoritesUnavailable: "已下架",
+  postShownInOriginalLanguage: "该贴子暂未提供当前语言版本，以原语言显示。",
   favoritesClearFilters: "清除筛选",
   favorites: "我的收藏",
   favoritesComingSoon: "功能即将推出",

src/pages/PostRedirect/index.tsx

@@ -5,13 +5,15 @@ import { langQuery, useI18n } from "../../i18n";
 import { useLocalizedPath } from "../../useLocalizedPath";
 import { MOCK_POSTS } from "../../mocks/mockPosts";
 import { POST_STREAM_USES_MOCK } from "../../components/messageStream/hooks/usePostStream";
+import { useToast } from "../../components/Toast";
 import type { Post } from "../../types/post";
 
 export function PostRedirect() {
   const { id } = useParams();
-  const { lang } = useI18n();
+  const { lang, t } = useI18n();
   const navigate = useNavigate();
   const lp = useLocalizedPath();
+  const { showToast } = useToast();
 
   useEffect(() => {
     if (!id) {
@@ -30,16 +32,25 @@ export function PostRedirect() {
       return;
     }
 
-    getJSON<Post>(
-      `/api/posts/${id}?lang=${encodeURIComponent(langQuery(lang))}`,
-    )
-      .then((post) => {
+    const goToPost = (post: Post) => {
       navigate(lp(`/browse?post=${encodeURIComponent(post.id)}`), {
         replace: true,
       });
+    };
+
+    getJSON<Post>(
+      `/api/posts/${id}?lang=${encodeURIComponent(langQuery(lang))}`,
+    )
+      .then(goToPost)
+      .catch(() => {
+        getJSON<Post>(`/api/posts/${id}`)
+          .then((post) => {
+            showToast(t("postShownInOriginalLanguage"));
+            goToPost(post);
           })
           .catch(() => navigate(lp("/browse"), { replace: true }));
-  }, [id, lang, navigate, lp]);
+      });
+  }, [id, lang, navigate, lp, showToast, t]);
 
   return <div className="text-neutral-400">…</div>;
 }