[collector views] wrap attempt to create a new Teil in a transaction

collector/views.py

@@ -1,5 +1,6 @@
 import logging
 
+from django.db import transaction
 from django.http import HttpRequest, HttpResponse, HttpResponseRedirect
 from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
@@ -30,7 +31,8 @@ def detail(request: HttpRequest, teil_id) -> HttpResponse:
 
 def enter(request: HttpRequest) -> HttpResponse:
     try:
-        Teil.objects.create(name=request.POST["new_name"])
+        with transaction.atomic():
+            Teil.objects.create(name=request.POST["new_name"])
     except Exception:
         logger.warning("Teil already existed")