core: scoreboard: bug fix

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "4.2.0",
+    "version": "4.2.1",
     "bin": "bin/hydrooj.js",
     "main": "src/plugin-api",
     "module": "src/plugin-api",

packages/hydrooj/src/model/contest.ts

@@ -429,7 +429,7 @@ const homework = buildContestRule({
         return columns;
     },
     async scoreboardRow(isExport, _, tdoc, pdict, udoc, rank, tsdoc) {
-        const tsddict = tsdoc.detail;
+        const tsddict = tsdoc.detail || {};
         const row: ScoreboardRow = [
             { type: 'rank', value: rank.toString() },
             {