Fix: skip incremental index writes when a re-embed migration is pending

src/paperless_ai/indexing.py

@@ -452,7 +452,15 @@ def llm_index_add_or_update_document(document: Document):
         _embed_nodes(new_nodes, get_embedding_model(config))
 
     with write_store(embed_model_name=get_configured_model_name(config)) as store:
-        _check_and_run_migrations(store)
+        needs_reembed = _check_and_run_migrations(store)
+        if needs_reembed:
+            logger.warning(
+                "Skipping incremental LLM index update for document %s: the "
+                "index requires re-embedding first. Run 'document_llmindex "
+                "rebuild' to resolve.",
+                document.id,
+            )
+            return
         store.upsert_document(str(document.id), new_nodes)
 
 
@@ -490,7 +498,14 @@ def llm_index_compact() -> None:
 def llm_index_remove_document(document: Document):
     """Remove a document's chunks from the LLM index."""
     with write_store() as store:
-        _check_and_run_migrations(store)
+        if _check_and_run_migrations(store):
+            logger.warning(
+                "Skipping removal of document %s from the LLM index: the "
+                "index requires re-embedding first. Run 'document_llmindex "
+                "rebuild' to resolve.",
+                document.id,
+            )
+            return
         store.delete(str(document.id))
 
 

src/paperless_ai/tests/test_ai_indexing.py

@@ -1,3 +1,4 @@
+import logging
 from pathlib import Path
 from unittest.mock import MagicMock
 from unittest.mock import patch
@@ -737,6 +738,7 @@ class TestLlmIndexLocking:
         mocker: pytest_mock.MockerFixture,
     ) -> None:
         mock_store = MagicMock()
+        mock_store.has_pending_migration.return_value = False
         mocker.patch(
             "paperless_ai.indexing.write_store",
             return_value=mocker.MagicMock(
@@ -757,12 +759,45 @@ class TestLlmIndexLocking:
 
         mock_store.upsert_document.assert_called_once()
 
+    def test_add_or_update_document_skips_write_when_reembed_pending(
+        self,
+        temp_llm_index_dir: Path,
+        mock_embed_model: FakeEmbedding,
+        mocker: pytest_mock.MockerFixture,
+    ) -> None:
+        """A pending re-embed migration must block the incremental write,
+        not let it proceed against a schema that just changed underneath it.
+        """
+        mock_store = MagicMock()
+        mock_store.has_pending_migration.return_value = True
+        mock_store.check_and_run_migrations.return_value = True
+        mocker.patch(
+            "paperless_ai.indexing.write_store",
+            return_value=mocker.MagicMock(
+                __enter__=mocker.MagicMock(return_value=mock_store),
+                __exit__=mocker.MagicMock(return_value=False),
+            ),
+        )
+        mock_node = MagicMock()
+        mock_node.get_content.return_value = "fake node text"
+        mocker.patch(
+            "paperless_ai.indexing.build_document_node",
+            return_value=[mock_node],
+        )
+
+        doc = MagicMock(spec=Document)
+        doc.id = 1
+        indexing.llm_index_add_or_update_document(doc)
+
+        mock_store.upsert_document.assert_not_called()
+
     def test_remove_document_uses_write_store(
         self,
         temp_llm_index_dir: Path,
         mocker: pytest_mock.MockerFixture,
     ) -> None:
         mock_store = MagicMock()
+        mock_store.has_pending_migration.return_value = False
         mocker.patch(
             "paperless_ai.indexing.write_store",
             return_value=mocker.MagicMock(
@@ -777,6 +812,31 @@ class TestLlmIndexLocking:
 
         mock_store.delete.assert_called_once_with("1")
 
+    def test_remove_document_skips_write_when_reembed_pending(
+        self,
+        temp_llm_index_dir: Path,
+        mocker: pytest_mock.MockerFixture,
+    ) -> None:
+        """A pending re-embed migration must block the delete too, for the
+        same consistency reason as the incremental-update path.
+        """
+        mock_store = MagicMock()
+        mock_store.has_pending_migration.return_value = True
+        mock_store.check_and_run_migrations.return_value = True
+        mocker.patch(
+            "paperless_ai.indexing.write_store",
+            return_value=mocker.MagicMock(
+                __enter__=mocker.MagicMock(return_value=mock_store),
+                __exit__=mocker.MagicMock(return_value=False),
+            ),
+        )
+
+        doc = MagicMock(spec=Document)
+        doc.id = 1
+        indexing.llm_index_remove_document(doc)
+
+        mock_store.delete.assert_not_called()
+
     def test_update_llm_index_rebuild_uses_write_store(
         self,
         temp_llm_index_dir: Path,
@@ -890,6 +950,34 @@ class TestLlmIndexMigrate:
         indexing.llm_index_migrate()
         store_mock.has_pending_migration.assert_called_once()
 
+    def test_logs_warning_when_reembed_needed(
+        self,
+        mocker: pytest_mock.MockerFixture,
+        caplog: pytest.LogCaptureFixture,
+    ) -> None:
+        """
+        GIVEN:
+            - AI/LLM index support is enabled
+            - A pending migration requires re-embedding
+        WHEN:
+            - llm_index_migrate() is called
+        THEN:
+            - A warning directs the operator to run a manual rebuild, since
+              this automatic check must never re-embed on its own
+        """
+        mocker.patch(
+            "paperless_ai.indexing.AIConfig",
+            return_value=mocker.Mock(llm_index_enabled=True),
+        )
+        store_mock = mocker.MagicMock()
+        store_mock.has_pending_migration.return_value = True
+        store_mock.check_and_run_migrations.return_value = True
+        write_store_cm = mocker.patch("paperless_ai.indexing.write_store")
+        write_store_cm.return_value.__enter__.return_value = store_mock
+        with caplog.at_level(logging.WARNING, logger="paperless_ai.indexing"):
+            indexing.llm_index_migrate()
+        assert "requires re-embedding" in caplog.text
+
 
 @pytest.mark.django_db
 class TestQuerySimilarDocuments: