Fixed #37024 -- Made SITE_ID system check validation use Site._meta.pk.

1 files changed, 24 insertions, 8 deletions

diff --git a/django/contrib/sites/checks.py b/django/contrib/sites/checks.py
index 66e8551bed..bf7c9b7dce 100644
--- a/django/contrib/sites/checks.py
+++ b/django/contrib/sites/checks.py
@@ -1,14 +1,30 @@
-from types import NoneType
-
 from django.conf import settings
 from django.core.checks import Error
+from django.core.exceptions import ValidationError
 
 
 def check_site_id(app_configs, **kwargs):
-    if hasattr(settings, "SITE_ID") and not isinstance(
-        settings.SITE_ID, (NoneType, int)
-    ):
-        return [
-            Error("The SITE_ID setting must be an integer", id="sites.E101"),
-        ]
+    # Inner import avoids AppRegistryNotReady
+    from django.contrib.sites.models import Site
+
+    if hasattr(settings, "SITE_ID"):
+        try:
+            site_id = Site._meta.pk.to_python(settings.SITE_ID)
+        except ValidationError as exc:
+            return [
+                Error(
+                    f"The SITE_ID setting failed to validate: {exc}.", id="sites.E101"
+                ),
+            ]
+        else:
+            # to_python() might coerce a SITE_ID of the wrong type to the valid
+            # type, e.g. "1" to 1 for AutoField.
+            if site_id != settings.SITE_ID:
+                expected_type = type(site_id).__name__
+                return [
+                    Error(
+                        f"The SITE_ID setting must be of type {expected_type}.",
+                        id="sites.E101",
+                    ),
+                ]
     return []