fix(login): ?error=__proto__ 会崩掉整个登录页 + 补全 error code 映射

app/[locale]/login/page.tsx

@@ -33,18 +33,10 @@ export default async function LoginPage({ params }: Props) {
           <p className="text-muted-foreground">{t("subheading")}</p>
         </div>
         <Suspense fallback={null}>
-          <LoginErrorNotice
-            messages={{
-              discord_canary: t("errorDiscordCanary"),
-              generic: t("errorGeneric"),
-            }}
-          />
+          <LoginErrorNotice />
         </Suspense>
         <div className="flex flex-col items-center gap-3">
           <SignInButton provider="github" label={t("github")} />
-          {/* Discord 登录灰度中：后端按 Discord id 白名单放行（auth.discord.allowlist），
-              名单外的人点了会被回调弹回 /login?error=discord_canary。GA（OTP wiring 完成、
-              清空白名单）后此按钮即对所有人开放。 */}
           <SignInButton provider="discord" label={t("discord")} />
         </div>
       </div>

app/components/LoginErrorNotice.tsx

@@ -1,25 +1,39 @@
 "use client";
 
+import { useTranslations } from "next-intl";
 import { useSearchParams } from "next/navigation";
 
-// 登录页顶端的错误提示。后端 OAuth 回调失败会 302 到 /login?error=xxx。
+// 后端 OAuth 回调失败会 302 到 /login?error=<code>，这里把 code 映射成 i18n key。
+//
+// 必须是显式白名单 + Object.hasOwn，不能拿 error 直接当对象索引：那样会命中原型链，
+// ?error=__proto__ 取到的是 Object.prototype（对象而非 undefined，所以 ?? 兜底不
+// 触发），把非字符串交给 React 渲染会抛错；/login 没有 error boundary，整个登录页
+// 会被替换成 Application error，连 GitHub 登录一起不可用。
+const ERROR_KEYS: Record<string, string> = {
+  discord_canary: "errorDiscordCanary",
+  oauth_state: "errorOauthState",
+  oauth_provider: "errorOauthProvider",
+  oauth_failed: "errorGeneric",
+};
+
+/** null 表示不显示提示。未知 code 一律落到通用文案，绝不透传原值。 */
+export function resolveErrorKey(error: string | null): string | null {
+  if (!error) return null;
+  return Object.hasOwn(ERROR_KEYS, error) ? ERROR_KEYS[error]! : "errorGeneric";
+}
+
 // 用 useSearchParams（客户端读 query）而非 server 读 searchParams，避免整页退回
 // 动态渲染（登录页要保持 SSG，见 CLAUDE.md 路由分类约束）。父级用 <Suspense> 包裹。
-// 文案由 server 端 getTranslations 取好后作为 prop 传入，省一套 client i18n provider。
-export function LoginErrorNotice({
-  messages,
-}: {
-  messages: Record<string, string>;
-}) {
-  const error = useSearchParams().get("error");
-  if (!error) return null;
-  const msg = messages[error] ?? messages.generic;
+export function LoginErrorNotice() {
+  const t = useTranslations("login");
+  const key = resolveErrorKey(useSearchParams().get("error"));
+  if (!key) return null;
   return (
     <div
       role="alert"
       className="w-full rounded-md border border-amber-300 bg-amber-50 px-4 py-3 text-sm text-amber-900 dark:border-amber-800 dark:bg-amber-950 dark:text-amber-200"
     >
-      {msg}
+      {t(key)}
     </div>
   );
 }

generated/doc-contributors.json

@@ -1,6 +1,6 @@
 {
   "repo": "InvolutionHell/involutionhell",
-  "generatedAt": "2026-07-24T13:55:10.610Z",
+  "generatedAt": "2026-07-25T18:05:19.341Z",
   "docsDir": "content/docs",
   "totalDocs": 144,
   "results": [

messages/en.json

@@ -72,7 +72,9 @@
     "github": "Sign in with GitHub",
     "discord": "Sign in with Discord",
     "errorDiscordCanary": "Discord sign-in is in limited testing and not open yet — stay tuned!",
-    "errorGeneric": "Sign-in didn't complete. Please try again."
+    "errorGeneric": "Sign-in didn't complete. Please try again.",
+    "errorOauthState": "Your sign-in session expired (took too long on the provider's page, or cookies were blocked). Please start the sign-in again.",
+    "errorOauthProvider": "This sign-in method isn't configured on the server — retrying won't help. Please contact an admin."
   },
   "settings": {
     "theme": {

messages/zh.json

@@ -72,7 +72,9 @@
     "github": "用 GitHub 登录",
     "discord": "用 Discord 登录",
     "errorDiscordCanary": "Discord 登录正在灰度测试中，暂未对外开放，敬请期待～",
-    "errorGeneric": "登录未完成，请重试。"
+    "errorGeneric": "登录未完成，请重试。",
+    "errorOauthState": "登录会话已失效（可能是等待授权太久，或浏览器拦截了 Cookie）。请重新点击登录。",
+    "errorOauthProvider": "该登录方式服务端未配置好，重试也无法解决。请联系管理员。"
   },
   "settings": {
     "theme": {

tests/login-error-notice.test.ts

@@ -0,0 +1,56 @@
+import { describe, expect, it } from "vitest";
+import enMessages from "../messages/en.json";
+import zhMessages from "../messages/zh.json";
+import { resolveErrorKey } from "../app/components/LoginErrorNotice";
+
+// 后端 OAuthController 实际会重定向的全部 error code。新增 code 时两边一起加，
+// 否则用户只会看到通用的"请重试"（对 oauth_provider 这类重试无用的错误是误导）。
+const BACKEND_ERROR_CODES = [
+  "discord_canary",
+  "oauth_failed",
+  "oauth_state",
+  "oauth_provider",
+];
+
+describe("resolveErrorKey", () => {
+  it("没有 error 参数时不显示提示", () => {
+    expect(resolveErrorKey(null)).toBeNull();
+    expect(resolveErrorKey("")).toBeNull();
+  });
+
+  it("后端每个 error code 都有专属文案，不塌缩成通用提示", () => {
+    for (const code of BACKEND_ERROR_CODES) {
+      const key = resolveErrorKey(code);
+      expect(key, `${code} 应有映射`).not.toBeNull();
+      if (code !== "oauth_failed") {
+        expect(key, `${code} 不该塌缩成通用文案`).not.toBe("errorGeneric");
+      }
+    }
+  });
+
+  // 回归：直接用 error 索引对象会命中原型链，?error=__proto__ 取到 Object.prototype
+  // （非 undefined，?? 兜底不触发），渲染非字符串会让整个登录页崩掉。
+  it("原型链上的键不会逃逸，一律落到通用文案", () => {
+    for (const key of [
+      "__proto__",
+      "constructor",
+      "toString",
+      "valueOf",
+      "hasOwnProperty",
+    ]) {
+      expect(resolveErrorKey(key), `${key} 必须被兜住`).toBe("errorGeneric");
+    }
+  });
+
+  it("未知 code 落到通用文案", () => {
+    expect(resolveErrorKey("wat")).toBe("errorGeneric");
+  });
+
+  it("解析出的 key 在 zh/en 里都存在", () => {
+    for (const code of [...BACKEND_ERROR_CODES, "__proto__", "wat"]) {
+      const key = resolveErrorKey(code)!;
+      expect(zhMessages.login, `zh 缺 ${key}`).toHaveProperty(key);
+      expect(enMessages.login, `en 缺 ${key}`).toHaveProperty(key);
+    }
+  });
+});