add TODO for known error

src/pretix/base/models/discount.py

@@ -306,6 +306,13 @@ class Discount(LoggedModel):
                 if possible_applications_cond * self.benefit_only_apply_to_cheapest_n_matches > len(benefit_idx_group):
                     # unused discount ("for each 1 ticket you buy, get 50% on 2 t-shirts", cart content: 1 ticket
                     # but 0 t-shirts) -> 2 shirt maybe potential discount (if the 1 ticket is not consumed by a later discount)
+
+                    #
+                    # TODO BUG:
+                    # cross-selling schlägt zu viele potential discounts vor ("consume" side of rule: sobald mindestens
+                    # ein voller block übrig ist zählt auch ein letzter, angebrochener block als voll mit)
+                    #
+
                     for i, idx in enumerate(condition_idx_group[n_groups * self.condition_min_count:]):
                         collect_potential_discounts[idx] += [
                             (self, self.benefit_only_apply_to_cheapest_n_matches, i // self.condition_min_count)