Improve player name display in tournaments

Adjust name display logic to handle cases with missing last names and
more flexible short name generation for tournament rounds

tournaments/models/player_registration.py

@@ -85,7 +85,9 @@ class PlayerRegistration(TournamentSubModel):
             return "Anonyme"
         name = self.name()
         if (len(name) > 20 or forced) and self.first_name:
-            if self.first_name and len(self.first_name) > 0:
+            if self.last_name is None:
+                name = self.first_name
+            elif self.first_name and len(self.first_name) > 0:
                 name = f"{self.first_name[0]}. {self.last_name}"
         if len(name) > 20 or forced:
             name_parts = self.last_name.split(" ")

tournaments/models/round.py

@@ -112,6 +112,9 @@ class Round(TournamentSubModel):
         return True
 
     def prepare_match_group(self, next_round, parent_round, loser_final, double_butterfly_mode, secondHalf):
+        short_names = double_butterfly_mode
+        if double_butterfly_mode and self.tournament.rounds.count() < 3:
+            short_names = False
         matches = self.matches.filter(disabled=False).order_by('index')
         if len(matches) == 0:
             return None
@@ -211,7 +214,7 @@ class Round(TournamentSubModel):
                     matches=first_half_matches,
                     round_id=self.id,
                     round_index=self.index,
-                    short_names=double_butterfly_mode
+                    short_names=short_names
                 )
                 return match_group