Fix: guard build_document_node against stale FK on deleted correspondent/doc type (#13318)

src/paperless_ai/indexing.py

@@ -5,6 +5,7 @@ from datetime import timedelta
 from typing import TYPE_CHECKING
 
 from django.conf import settings
+from django.core.exceptions import ObjectDoesNotExist
 from django.utils import timezone
 from filelock import FileLock
 from filelock import ReadWriteLock
@@ -167,6 +168,19 @@ def write_store(embed_model_name: str | None = None):
         yield store
 
 
+def _safe_related_name(document: Document, field: str) -> str | None:
+    """
+    Returns the ``name`` of a related object (correspondent, document_type,
+    storage_path), or None if the FK is unset or points at a row that has
+    since been deleted (e.g. concurrently with this call).
+    """
+    try:
+        related = getattr(document, field)
+    except ObjectDoesNotExist:
+        return None
+    return related.name if related else None
+
+
 def build_document_node(
     document: Document,
     *,
@@ -180,14 +194,10 @@ def build_document_node(
         "document_id": str(document.id),
         "title": document.title,
         "tags": [t.name for t in document.tags.all()],
-        "correspondent": document.correspondent.name
-        if document.correspondent
-        else None,
-        "document_type": document.document_type.name
-        if document.document_type
-        else None,
+        "correspondent": _safe_related_name(document, "correspondent"),
+        "document_type": _safe_related_name(document, "document_type"),
         "filename": document.filename,
-        "storage_path": document.storage_path.name if document.storage_path else None,
+        "storage_path": _safe_related_name(document, "storage_path"),
         "archive_serial_number": document.archive_serial_number,
         "created": document.created.isoformat() if document.created else None,
         "added": document.added.isoformat() if document.added else None,

src/paperless_ai/tests/test_ai_indexing.py

@@ -8,7 +8,9 @@ from django.test import override_settings
 from django.utils import timezone
 from llama_index.core.schema import MetadataMode
 
+from documents.models import Correspondent
 from documents.models import Document
+from documents.models import DocumentType
 from documents.models import PaperlessTask
 from documents.signals import document_consumption_finished
 from documents.signals import document_updated
@@ -95,6 +97,38 @@ def test_build_document_node_structured_fields_in_metadata(
         assert "modified" in node.metadata
 
 
+@pytest.mark.django_db
+def test_build_document_node_survives_concurrently_deleted_correspondent(
+    real_document: Document,
+) -> None:
+    """Regression test for #13314.
+
+    If a document's correspondent (or document type) is deleted after the
+    in-memory Document instance was loaded but before build_document_node
+    resolves the relation, accessing the FK must not raise -- it should
+    behave like an unset FK and produce None in the metadata instead of
+    aborting the whole indexing pass.
+    """
+    correspondent = Correspondent.objects.create(name="Stale Correspondent")
+    document_type = DocumentType.objects.create(name="Stale Type")
+    real_document.correspondent = correspondent
+    real_document.document_type = document_type
+    real_document.save()
+
+    # Re-fetch to get an instance whose correspondent/document_type relations
+    # are unresolved (not yet cached), mirroring a task that loaded the
+    # document before the concurrent deletion below.
+    stale_document = Document.objects.get(pk=real_document.pk)
+
+    correspondent.delete()
+    document_type.delete()
+
+    nodes = indexing.build_document_node(stale_document)
+    assert len(nodes) > 0
+    assert nodes[0].metadata["correspondent"] is None
+    assert nodes[0].metadata["document_type"] is None
+
+
 @pytest.mark.django_db
 def test_build_document_node_excludes_document_id_from_llm_context(
     real_document: Document,