ModelAdmin.search_fields fails for DecimalField and __exact

[Klaas van Schelven]

From the docs:

If you don’t want to use icontains as the lookup, you can use any lookup by appending it the field. For example, you could use exact by setting search_fields to first_name__exact

However, when I do this for any DecimalField, and enter any non-parsable (as a Decimal) value in the search box, I get the following:

Internal Server Error: /admin/valuta/redacted/
Traceback (most recent call last):
  File "..../lib/python3.10/site-packages/django/db/models/fields/__init__.py", line 1552, in to_python
    return decimal.Decimal(value)
decimal.InvalidOperation: [<class 'decimal.ConversionSyntax'>]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "..../lib/python3.10/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "..../lib/python3.10/site-packages/django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "..../lib/python3.10/site-packages/django/contrib/admin/options.py", line 616, in wrapper
    return self.admin_site.admin_view(view)(*args, **kwargs)
  File "..../lib/python3.10/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
    response = view_func(request, *args, **kwargs)
  File "..../lib/python3.10/site-packages/django/views/decorators/cache.py", line 44, in _wrapped_view_func
    response = view_func(request, *args, **kwargs)
  File "..../lib/python3.10/site-packages/django/contrib/admin/sites.py", line 232, in inner
    return view(request, *args, **kwargs)
  File "..../lib/python3.10/site-packages/django/utils/decorators.py", line 43, in _wrapper
    return bound_method(*args, **kwargs)
  File "..../lib/python3.10/site-packages/django/utils/decorators.py", line 130, in _wrapped_view
    response = view_func(request, *args, **kwargs)
  File "..../lib/python3.10/site-packages/django/contrib/admin/options.py", line 1697, in changelist_view
    cl = self.get_changelist_instance(request)
  File "..../lib/python3.10/site-packages/django/contrib/admin/options.py", line 736, in get_changelist_instance
    return ChangeList(
  File "..../lib/python3.10/site-packages/django/contrib/admin/views/main.py", line 99, in __init__
    self.queryset = self.get_queryset(request)
  File "..../lib/python3.10/site-packages/django/contrib/admin/views/main.py", line 476, in get_queryset
    qs, search_may_have_duplicates = self.model_admin.get_search_results(
  File "..../lib/python3.10/site-packages/django/contrib/admin/options.py", line 1032, in get_search_results
    queryset = queryset.filter(reduce(operator.or_, or_queries))
  File "..../lib/python3.10/site-packages/django/db/models/query.py", line 941, in filter
    return self._filter_or_exclude(False, args, kwargs)
  File "..../lib/python3.10/site-packages/django/db/models/query.py", line 961, in _filter_or_exclude
    clone._filter_or_exclude_inplace(negate, args, kwargs)
  File "..../lib/python3.10/site-packages/django/db/models/query.py", line 968, in _filter_or_exclude_inplace
    self._query.add_q(Q(*args, **kwargs))
  File "..../lib/python3.10/site-packages/django/db/models/sql/query.py", line 1416, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "..../lib/python3.10/site-packages/django/db/models/sql/query.py", line 1435, in _add_q
    child_clause, needed_inner = self.build_filter(
  File "..../lib/python3.10/site-packages/django/db/models/sql/query.py", line 1288, in build_filter
    return self._add_q(
  File "..../lib/python3.10/site-packages/django/db/models/sql/query.py", line 1435, in _add_q
    child_clause, needed_inner = self.build_filter(
  File "..../lib/python3.10/site-packages/django/db/models/sql/query.py", line 1370, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "..../lib/python3.10/site-packages/django/db/models/sql/query.py", line 1216, in build_lookup
    lookup = lookup_class(lhs, rhs)
  File "..../lib/python3.10/site-packages/django/db/models/lookups.py", line 25, in __init__
    self.rhs = self.get_prep_lookup()
  File "..../lib/python3.10/site-packages/django/db/models/lookups.py", line 77, in get_prep_lookup
    return self.lhs.output_field.get_prep_value(self.rhs)
  File "..../lib/python3.10/site-packages/django/db/models/fields/__init__.py", line 1565, in get_prep_value
    return self.to_python(value)
  File "..../lib/python3.10/site-packages/django/db/models/fields/__init__.py", line 1554, in to_python
    raise exceptions.ValidationError(
django.core.exceptions.ValidationError: ['‘adf’ value must be a decimal number.']

[Mariusz Felisiak]

Duplicate of #26001.