Fix: respect subpath in logout, share link and auto-login redirects (#14476)

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

src/documents/tests/test_share_link_bundles.py

@@ -7,6 +7,7 @@ from unittest import mock
 
 from django.conf import settings
 from django.contrib.auth.models import User
+from django.test import override_settings
 from django.utils import timezone
 from rest_framework import serializers
 from rest_framework import status
@@ -225,6 +226,25 @@ class ShareLinkBundleAPITests(DirectoriesMixin, APITestCase):
         self.assertEqual(response.status_code, status.HTTP_302_FOUND)
         self.assertIn("sharelink_notfound=1", response["Location"])
 
+    @override_settings(LOGIN_URL="/paperless/accounts/login/")
+    def test_unknown_share_link_redirects_under_subpath(self) -> None:
+        """
+        GIVEN:
+            - Paperless is served under a subpath
+        WHEN:
+            - An unknown public share link is requested
+        THEN:
+            - The redirect to the login page keeps the subpath
+        """
+        self.client.logout()
+        response = self.client.get("/share/unknownsharelink/")
+
+        self.assertEqual(response.status_code, status.HTTP_302_FOUND)
+        self.assertEqual(
+            response["Location"],
+            "/paperless/accounts/login/?sharelink_notfound=1",
+        )
+
     def test_share_link_missing_file_redirects(self) -> None:
         """
         GIVEN:

src/documents/views.py

@@ -4911,7 +4911,7 @@ class SharedLinkView(View):
                 share_link.expiration is not None
                 and share_link.expiration < timezone.now()
             ):
-                return HttpResponseRedirect("/accounts/login/?sharelink_expired=1")
+                return HttpResponseRedirect(f"{settings.LOGIN_URL}?sharelink_expired=1")
             try:
                 return serve_file(
                     doc=share_link.document,
@@ -4920,14 +4920,16 @@ class SharedLinkView(View):
                     disposition="inline",
                 )
             except FileNotFoundError:
-                return HttpResponseRedirect("/accounts/login/?sharelink_notfound=1")
+                return HttpResponseRedirect(
+                    f"{settings.LOGIN_URL}?sharelink_notfound=1",
+                )
 
         bundle = ShareLinkBundle.objects.filter(slug=slug).first()
         if bundle is None:
-            return HttpResponseRedirect("/accounts/login/?sharelink_notfound=1")
+            return HttpResponseRedirect(f"{settings.LOGIN_URL}?sharelink_notfound=1")
 
         if bundle.expiration is not None and bundle.expiration < timezone.now():
-            return HttpResponseRedirect("/accounts/login/?sharelink_expired=1")
+            return HttpResponseRedirect(f"{settings.LOGIN_URL}?sharelink_expired=1")
 
         if bundle.status in {
             ShareLinkBundle.Status.PENDING,