Check-in: Handle products without variation in simulator

src/pretix/base/services/checkin.py

@@ -114,11 +114,17 @@ def _logic_annotate_for_graphic_explain(rules, ev, rule_data, now_dt):
                 except Item.DoesNotExist:
                     val = "?"
             elif var == "variation":
+                if not val:
+                    val = "-"
+                else:
                     try:
                         val = str(ItemVariation.objects.get(item__event=event, pk=val))
                     except ItemVariation.DoesNotExist:
                         val = "?"
             elif var == "gate":
+                if not val:
+                    val = "-"
+                else:
                     try:
                         val = str(event.organizer.gates.get(pk=val))
                     except Gate.DoesNotExist: