Fix user search (#313)

(cherry picked from commit 9a1d3c3)

judge/views/user.py

@@ -555,7 +555,7 @@ class UserList(QueryStringSortMixin, InfinitePaginationMixin, DiggPaginatorMixin
     default_sort = '-performance_points'
 
     def get_queryset(self):
-        return (Profile.objects.filter(is_unlisted=False).order_by(self.order)
+        return (Profile.objects.filter(is_unlisted=False).order_by(self.order, 'id')
                 .prefetch_related(Prefetch('user', queryset=User.objects.only('username', 'first_name')))
                 .prefetch_related(Prefetch('organizations',
                                   queryset=Organization.objects.filter(is_unlisted=False).only('name', 'id', 'slug')))
@@ -590,7 +590,7 @@ class ContribList(QueryStringSortMixin, DiggPaginatorMixin, TitleMixin, ListView
     default_sort = '-contribution_points'
 
     def get_queryset(self):
-        return (Profile.objects.filter(is_unlisted=False).order_by(self.order)
+        return (Profile.objects.filter(is_unlisted=False).order_by(self.order, 'id')
                 .prefetch_related(Prefetch('user', queryset=User.objects.only('username', 'first_name')))
                 .prefetch_related(Prefetch('organizations',
                                   queryset=Organization.objects.filter(is_unlisted=False).only('name', 'id', 'slug')))
@@ -631,9 +631,13 @@ def user_ranking_redirect(request):
     except KeyError:
         raise Http404()
     user = get_object_or_404(Profile, user__username=username)
-    rank = Profile.objects.filter(is_unlisted=False, performance_points__gt=user.performance_points).count()
+    # Assume using MySQL. NULL is considered smaller than any non-NULL value.
+    if user.rating is None:
+        rank = Profile.objects.filter(is_unlisted=False, rating__isnull=False).count()
+    else:
+        rank = Profile.objects.filter(is_unlisted=False, rating__gt=user.rating).count()
     rank += Profile.objects.filter(
-        is_unlisted=False, performance_points__exact=user.performance_points, id__lt=user.id,
+        is_unlisted=False, rating__exact=user.rating, id__lt=user.id,
     ).count()
     page = rank // UserList.paginate_by
     return HttpResponseRedirect('%s%s#!%s' % (reverse('user_list'), '?page=%d' % (page + 1) if page else '', username))