fix(login): render login page when the Site row for SITE_ID is missing

dojo/user/ui/views.py

@@ -11,6 +11,9 @@
 from django.contrib.auth.forms import AuthenticationForm, PasswordResetForm
 from django.contrib.auth.views import LoginView, PasswordResetConfirmView, PasswordResetView
 from django.contrib.humanize.templatetags.humanize import naturaltime
+from django.contrib.sites.models import Site
+from django.contrib.sites.requests import RequestSite
+from django.contrib.sites.shortcuts import get_current_site
 from django.core import serializers
 from django.core.exceptions import PermissionDenied, ValidationError
 from django.core.mail import get_connection
@@ -59,6 +62,27 @@ class DojoLoginView(LoginView):
     template_name = "dojo/login.html"
     authentication_form = AuthenticationForm
 
+    def get_context_data(self, **kwargs):
+        # Django's LoginView.get_context_data() resolves the current Site via
+        # get_current_site(), which raises Site.DoesNotExist (surfacing as an
+        # HTTP 500 on the login page) when the django_site row referenced by
+        # SITE_ID is absent on an instance. Resolve the site defensively and
+        # fall back to a request-derived site -- mirroring what Django itself
+        # does when the sites framework is not installed -- so the login page
+        # always renders instead of 500ing.
+        try:
+            current_site = get_current_site(self.request)
+        except Site.DoesNotExist:
+            current_site = RequestSite(self.request)
+        context = super(LoginView, self).get_context_data(**kwargs)
+        context.update({
+            self.redirect_field_name: self.get_redirect_url(),
+            "site": current_site,
+            "site_name": current_site.name,
+            **(self.extra_context or {}),
+        })
+        return context
+
     def form_valid(self, form):
         last_login = None
         with contextlib.suppress(Exception):

unittests/test_login_view_missing_site.py

@@ -0,0 +1,32 @@
+from django.contrib.sites.models import Site
+from django.test import TestCase, override_settings
+
+
+# Regression: GET /login returned HTTP 500 (Site.DoesNotExist) on instances
+# whose django_site row referenced by SITE_ID was absent. Django's LoginView
+# resolves the current Site while building the login page context, and raises
+# when that row is missing; the login page must render regardless.
+@override_settings(SECURE_SSL_REDIRECT=False)
+class TestLoginViewMissingSite(TestCase):
+
+    def test_login_page_renders_when_site_present(self):
+        # Control case: the default Site row exists, login renders normally.
+        self.assertTrue(Site.objects.exists())
+        response = self.client.get("/login")
+        self.assertEqual(
+            response.status_code, 200,
+            msg=f"login GET returned {response.status_code} with a Site row present",
+        )
+
+    def test_login_page_renders_when_site_row_missing(self):
+        # Reproduce the reported condition: no django_site row matches SITE_ID.
+        Site.objects.all().delete()
+        self.assertFalse(Site.objects.exists())
+        response = self.client.get("/login")
+        self.assertEqual(
+            response.status_code, 200,
+            msg=(
+                f"login GET returned {response.status_code} when the Site row is "
+                "missing (expected 200, not a Site.DoesNotExist 500)"
+            ),
+        )