core: fix admin can not view all related contest (#1011)

packages/hydrooj/src/handler/problem.ts

@@ -391,7 +391,9 @@ export class ProblemDetailHandler extends ContestDetailBaseHandler {
             [this.response.body.ctdocs, this.response.body.htdocs] = (await Promise.all([
                 contest.getRelated(this.args.domainId, this.pdoc.docId),
                 contest.getRelated(this.args.domainId, this.pdoc.docId, 'homework'),
-            ])).map((tdocs) => tdocs.filter((tdoc) => !tdoc.assign?.length || Set.intersection(tdoc.assign, this.user.group).size));
+            ])).map((tdocs) => tdocs.filter((tdoc) =>
+                this.user.hasPerm(PERM.PERM_VIEW_HIDDEN_CONTEST) || !tdoc.assign?.length || Set.intersection(tdoc.assign, this.user.group).size,
+            ));
         }
     }