Fix editing of variannts (#1411)

Author: leotsarev

src/JoinRpg.Portal/Controllers/GameFieldController.cs

@@ -285,7 +285,7 @@ await FieldSetupService.UpdateFieldValueVariant(new UpdateFieldValueVariantReque
                     viewModel.ProgrammaticValue,
                     viewModel.Price,
                     viewModel.PlayerSelectable,
-                    viewModel.GetTimeSlotRequest(field, Request.Form["TimeSlotStartTime"][0])
+                    viewModel.GetTimeSlotRequest(field, Request.Form["TimeSlotStartTime"].FirstOrDefault())
                     ));
 
                 return RedirectToAction("Edit", new { viewModel.ProjectId, projectFieldId = viewModel.ProjectFieldId });

src/JoinRpg.WebPortal.Models/FieldSetup/GameFieldDropdownValueViewModelBase.cs

@@ -61,9 +61,9 @@ public GameFieldDropdownValueViewModelBase(ProjectField field)
 
         public GameFieldDropdownValueViewModelBase() { }
 
-        public TimeSlotOptions? GetTimeSlotRequest(ProjectField field, string value)
+        public TimeSlotOptions? GetTimeSlotRequest(ProjectField field, string? value)
         {
-            return field.IsTimeSlot()
+            return value is not null && field.IsTimeSlot()
                 ? new TimeSlotOptions
                 {
                     StartTime = DateTimeOffset.ParseExact(