Fixed #35090 -- Deprecated registering URL converters with the same name.

django/urls/converters.py

@@ -1,5 +1,8 @@
 import functools
 import uuid
+import warnings
+
+from django.utils.deprecation import RemovedInDjango60Warning
 
 
 class IntConverter:
@@ -53,6 +56,15 @@ REGISTERED_CONVERTERS = {}
 
 
 def register_converter(converter, type_name):
+    if type_name in REGISTERED_CONVERTERS or type_name in DEFAULT_CONVERTERS:
+        # RemovedInDjango60Warning: when the deprecation ends, replace with
+        # raise ValueError(f"Converter {type_name} is already registered.")
+        warnings.warn(
+            f"Converter {type_name!r} is already registered. Support for overriding "
+            "registered converters is deprecated and will be removed in Django 6.0.",
+            RemovedInDjango60Warning,
+            stacklevel=2,
+        )
     REGISTERED_CONVERTERS[type_name] = converter()
     get_converters.cache_clear()