Fixed #36239 -- Fixed a crash in ManyToManyField.through_fields check when to model is invalid.

Signed-off-by: saJaeHyukc <wogur981208@gmail.com>

django/db/models/fields/related.py

@@ -1707,13 +1707,18 @@ class ManyToManyField(RelatedField):
                             and getattr(field.remote_field, "model", None)
                             == related_model
                         ):
+                            related_object_name = (
+                                related_model
+                                if isinstance(related_model, str)
+                                else related_model._meta.object_name
+                            )
                             errors.append(
                                 checks.Error(
                                     "'%s.%s' is not a foreign key to '%s'."
                                     % (
                                         through._meta.object_name,
                                         field_name,
-                                        related_model._meta.object_name,
+                                        related_object_name,
                                     ),
                                     hint=hint,
                                     obj=self,

tests/invalid_models_tests/test_relative_fields.py

@@ -2185,3 +2185,45 @@ class M2mThroughFieldsTests(SimpleTestCase):
                 ),
             ],
         )
+
+    def test_invalid_to_argument_with_through(self):
+        class Foo(models.Model):
+            pass
+
+        class Bar(models.Model):
+            foos = models.ManyToManyField(
+                to="Fo",
+                through="FooBar",
+                through_fields=("bar", "foo"),
+            )
+
+        class FooBar(models.Model):
+            foo = models.ForeignKey("Foo", on_delete=models.CASCADE)
+            bar = models.ForeignKey("Bar", on_delete=models.CASCADE)
+
+        field = Bar._meta.get_field("foos")
+
+        self.assertEqual(
+            field.check(from_model=Bar),
+            [
+                Error(
+                    "Field defines a relation with model 'Fo', "
+                    "which is either not installed, or is abstract.",
+                    obj=field,
+                    id="fields.E300",
+                ),
+                Error(
+                    "The model is used as an intermediate model by "
+                    "'invalid_models_tests.Bar.foos', "
+                    "but it does not have a foreign key to 'Bar' "
+                    "or 'invalid_models_tests.Fo'.",
+                    obj=FooBar,
+                    id="fields.E336",
+                ),
+                Error(
+                    "'FooBar.foo' is not a foreign key to 'Fo'.",
+                    obj=field,
+                    id="fields.E339",
+                ),
+            ],
+        )