core: fix user_detail

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "3.2.12",
+    "version": "3.2.13",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",

packages/hydrooj/src/handler/user.ts

@@ -297,7 +297,7 @@ class UserDetailHandler extends Handler {
         const pdocs: ProblemDoc[] = [];
         const acInfo: Record<string, number> = {};
         const canViewHidden = this.user.hasPerm(PERM.PERM_VIEW_PROBLEM_HIDDEN) || this.user._id;
-        await Promise.all([domainId, ...union.union].map(async (did) => {
+        await Promise.all([domainId, ...(union?.union || [])].map(async (did) => {
             const psdocs = await problem.getMultiStatus(did, { uid, status: STATUS.STATUS_ACCEPTED }).toArray();
             pdocs.push(...Object.values(await problem.getList(did, psdocs.map((i) => i.docId), canViewHidden, false, undefined, true)));
         }));