Be more defensive in redirect code (#11427)

* Be more defensive in redirect code

Fixes #11338

* Try to add a test

* Rename test

readthedocs/proxito/views/serve.py

@@ -122,6 +122,9 @@ def get(self, request, path):
         and if the project is marked as spam.
         """
         unresolved_domain = request.unresolved_domain
+        # Protect against bad requests to API hosts that don't set this attribute.
+        if not unresolved_domain:
+            raise Http404
         # Handle requests that need canonicalizing first,
         # e.g. HTTP -> HTTPS, redirect to canonical domain, etc.
         # We run this here to reduce work we need to do on easily cached responses.

readthedocs/rtd_tests/tests/test_footer.py

@@ -318,6 +318,12 @@ def test_not_built_versions(self):
         self.assertIn("/en/latest/", response.data["html"])
         self.assertNotIn("/en/2.0/", response.data["html"])
 
+    def test_invalid_footer_url(self):
+        # The built versions appears on the footer
+        self.url = reverse("footer_html") + "/invalid/url"
+        response = self.render()
+        self.assertEqual(response.status_code, 404)
+
 
 class TestFooterHTML(BaseTestFooterHTML, TestCase):
     pass