Fix: use version page_count for versioned document (#14280)

src/documents/tests/test_api_document_versions.py

@@ -19,6 +19,7 @@ from documents.models import Document
 from documents.versioning import annotate_effective_content
 from documents.views import DocumentSelectionMixin
 from paperless_testing.dirs import DirectoriesMixin
+from paperless_testing.factories import DocumentFactory
 from paperless_testing.factories import UserFactory
 from paperless_testing.http import read_streaming_response
 from paperless_testing.permissions import grant_global
@@ -821,6 +822,26 @@ class TestDocumentVersioningApi(DirectoriesMixin, APITestCase):
         self.assertEqual(resp.status_code, status.HTTP_200_OK)
         self.assertEqual(resp.data["content"], "v1-content")
 
+    def test_page_count_resolves_to_latest_version(self) -> None:
+        root = DocumentFactory(page_count=2)
+        DocumentFactory(root_document=root, version_index=1, page_count=1)
+        unversioned = DocumentFactory(page_count=5)
+
+        resp = self.client.get("/api/documents/?fields=id,page_count")
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(
+            {doc["id"]: doc["page_count"] for doc in resp.data["results"]},
+            {root.id: 1, unversioned.id: 5},
+        )
+
+        resp = self.client.get(f"/api/documents/{root.id}/")
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(resp.data["page_count"], 1)
+
+        resp = self.client.get(f"/api/documents/{root.id}/?version={root.id}")
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(resp.data["page_count"], 2)
+
     def _make_root_with_out_of_order_versions(self) -> tuple[Document, ...]:
         """
         A root whose newest version has a *lower* id than an older one, which is