Delete contest in form before adding

judge/models/contest.py

@@ -19,7 +19,7 @@
     MOSS_LANG_PYTHON,
     MOSS_LANG_PASCAL,
 )
-from datetime import timedelta
+from datetime import timedelta, datetime
 
 from judge import contest_format
 from judge.models.problem import Problem
@@ -371,6 +371,13 @@ def clean(self):
                 )
 
     def save(self, *args, **kwargs):
+        earliest_start_time = datetime(2020, 1, 1).replace(tzinfo=timezone.utc)
+        if self.start_time < earliest_start_time:
+            self.start_time = earliest_start_time
+
+        if self.end_time < self.start_time:
+            self.end_time = self.start_time + timedelta(hours=1)
+
         one_year_later = self.start_time + timedelta(days=365)
         if self.end_time > one_year_later:
             self.end_time = one_year_later

judge/views/organization.py

@@ -991,12 +991,15 @@ def post(self, request, *args, **kwargs):
             return res
         problem_formset = self.get_problem_formset(True)
         if problem_formset.is_valid():
+            for problem_form in problem_formset:
+                if problem_form.cleaned_data.get("DELETE") and problem_form.instance.pk:
+                    problem_form.instance.delete()
+
             for problem_form in problem_formset.save(commit=False):
                 if problem_form:
                     problem_form.contest = self.contest
                     problem_form.save()
-            for problem_form in problem_formset.deleted_objects:
-                problem_form.delete()
+
             super().post(request, *args, **kwargs)
             return HttpResponseRedirect(
                 reverse(