[5.2.x] Fixed #36903 -- Fixed further NameErrors when inspecting functions with deferred annotations.

Provide a wrapper for safe introspection of user functions on Python 3.14+.

Follow-up to 601914722956cc41f1f2c53972d669ddee6ffc04.
Backport of 56ed37e17e5b1a509aa68a0c797dcff34fcc1366 from main.

6 files changed, 23 insertions, 23 deletions

diff --git a/django/contrib/auth/__init__.py b/django/contrib/auth/__init__.py
index 84ca239558..e181cee6ae 100644
--- a/django/contrib/auth/__init__.py
+++ b/django/contrib/auth/__init__.py
@@ -1,4 +1,3 @@
-import inspect
 import re
 import warnings
 
@@ -8,6 +7,7 @@ from django.core.exceptions import ImproperlyConfigured, PermissionDenied
 from django.middleware.csrf import rotate_token
 from django.utils.crypto import constant_time_compare
 from django.utils.deprecation import RemovedInDjango61Warning
+from django.utils.inspect import signature
 from django.utils.module_loading import import_string
 from django.views.decorators.debug import sensitive_variables
 
@@ -42,7 +42,7 @@ def get_backends():
 
 def _get_compatible_backends(request, **credentials):
     for backend, backend_path in _get_backends(return_tuples=True):
-        backend_signature = inspect.signature(backend.authenticate)
+        backend_signature = signature(backend.authenticate)
         try:
             backend_signature.bind(request, **credentials)
         except TypeError:
diff --git a/django/core/checks/security/csrf.py b/django/core/checks/security/csrf.py
index d00f2259c6..51be377f48 100644
--- a/django/core/checks/security/csrf.py
+++ b/django/core/checks/security/csrf.py
@@ -1,6 +1,5 @@
-import inspect
-
 from django.conf import settings
+from django.utils.inspect import signature
 
 from .. import Error, Tags, Warning, register
 
@@ -57,7 +56,7 @@ def check_csrf_failure_view(app_configs, **kwargs):
         errors.append(Error(msg, id="security.E102"))
     else:
         try:
-            inspect.signature(view).bind(None, reason=None)
+            signature(view).bind(None, reason=None)
         except TypeError:
             msg = (
                 "The CSRF failure view '%s' does not take the correct number of "
diff --git a/django/core/checks/urls.py b/django/core/checks/urls.py
index aef2bfebb0..0980ecc3c9 100644
--- a/django/core/checks/urls.py
+++ b/django/core/checks/urls.py
@@ -1,8 +1,8 @@
-import inspect
 from collections import Counter
 
 from django.conf import settings
 from django.core.exceptions import ViewDoesNotExist
+from django.utils.inspect import signature
 
 from . import Error, Tags, Warning, register
 
@@ -142,10 +142,9 @@ def check_custom_error_handlers(app_configs, **kwargs):
             ).format(status_code=status_code, path=path)
             errors.append(Error(msg, hint=str(e), id="urls.E008"))
             continue
-        signature = inspect.signature(handler)
         args = [None] * num_parameters
         try:
-            signature.bind(*args)
+            signature(handler).bind(*args)
         except TypeError:
             msg = (
                 "The custom handler{status_code} view '{path}' does not "
diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index 4284c84375..f830df82c2 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -1,7 +1,6 @@
 import copy
 import datetime
 import functools
-import inspect
 from collections import defaultdict
 from decimal import Decimal
 from enum import Enum
@@ -17,6 +16,7 @@ from django.db.models.query_utils import Q
 from django.utils.deconstruct import deconstructible
 from django.utils.functional import cached_property, classproperty
 from django.utils.hashable import make_hashable
+from django.utils.inspect import signature
 
 
 class SQLiteNumericMixin:
@@ -521,7 +521,7 @@ class Expression(BaseExpression, Combinable):
     @classproperty
     @functools.lru_cache(maxsize=128)
     def _constructor_signature(cls):
-        return inspect.signature(cls.__init__)
+        return signature(cls.__init__)
 
     @classmethod
     def _identity(cls, value):
diff --git a/django/template/base.py b/django/template/base.py
index 5a0941564d..80ccd0d423 100644
--- a/django/template/base.py
+++ b/django/template/base.py
@@ -58,7 +58,7 @@ from enum import Enum
 from django.template.context import BaseContext
 from django.utils.formats import localize
 from django.utils.html import conditional_escape
-from django.utils.inspect import lazy_annotations
+from django.utils.inspect import lazy_annotations, signature
 from django.utils.regex_helper import _lazy_re_compile
 from django.utils.safestring import SafeData, SafeString, mark_safe
 from django.utils.text import get_text_list, smart_split, unescape_string_literal
@@ -927,12 +927,12 @@ class Variable:
                             current = current()
                         except TypeError:
                             try:
-                                signature = inspect.signature(current)
+                                current_signature = signature(current)
                             except ValueError:  # No signature found.
                                 current = context.template.engine.string_if_invalid
                             else:
                                 try:
-                                    signature.bind()
+                                    current_signature.bind()
                                 except TypeError:  # Arguments *were* required.
                                     # Invalid method call.
                                     current = context.template.engine.string_if_invalid
diff --git a/django/utils/inspect.py b/django/utils/inspect.py
index 6f6bd7b7b9..b5d968062b 100644
--- a/django/utils/inspect.py
+++ b/django/utils/inspect.py
@@ -17,16 +17,7 @@ if PY314:
 
 @functools.lru_cache(maxsize=512)
 def _get_func_parameters(func, remove_first):
-    # As the annotations are not used in any case, inspect the signature with
-    # FORWARDREF to leave any deferred annotations unevaluated.
-    if PY314:
-        signature = inspect.signature(
-            func, annotation_format=annotationlib.Format.FORWARDREF
-        )
-    else:
-        signature = inspect.signature(func)
-
-    parameters = tuple(signature.parameters.values())
+    parameters = tuple(signature(func).parameters.values())
     if remove_first:
         parameters = parameters[1:]
     return parameters
@@ -120,3 +111,14 @@ def lazy_annotations():
             yield
         finally:
             inspect._signature_from_callable = original_helper
+
+
+def signature(obj):
+    """
+    A wrapper around inspect.signature that leaves deferred annotations
+    unevaluated on Python 3.14+, since they are not used in our case.
+    """
+    if PY314:
+        return inspect.signature(obj, annotation_format=annotationlib.Format.FORWARDREF)
+    else:
+        return inspect.signature(obj)