First, release ASNs before document replacement (and restore if needed)

src/documents/bulk_edit.py

@@ -7,7 +7,6 @@ from pathlib import Path
 from typing import TYPE_CHECKING
 from typing import Literal
 
-from celery import chain
 from celery import chord
 from celery import group
 from celery import shared_task
@@ -38,6 +37,42 @@ if TYPE_CHECKING:
 logger: logging.Logger = logging.getLogger("paperless.bulk_edit")
 
 
+@shared_task(bind=True)
+def restore_archive_serial_numbers_task(
+    self,
+    backup: dict[int, int],
+    *args,
+    **kwargs,
+) -> None:
+    restore_archive_serial_numbers(backup)
+
+
+def release_archive_serial_numbers(doc_ids: list[int]) -> dict[int, int]:
+    """
+    Clears ASNs on documents that are about to be replaced so new documents
+    can be assigned ASNs without uniqueness collisions. Returns a backup map
+    of doc_id -> previous ASN for potential restoration.
+    """
+    qs = Document.objects.filter(
+        id__in=doc_ids,
+        archive_serial_number__isnull=False,
+    ).only("pk", "archive_serial_number")
+    backup = dict(qs.values_list("pk", "archive_serial_number"))
+    qs.update(archive_serial_number=None)
+    logger.info(f"Released archive serial numbers for documents {list(backup.keys())}")
+    return backup
+
+
+def restore_archive_serial_numbers(backup: dict[int, int]) -> None:
+    """
+    Restores ASNs using the provided backup map, intended for
+    rollback when replacement consumption fails.
+    """
+    for doc_id, asn in backup.items():
+        Document.objects.filter(pk=doc_id).update(archive_serial_number=asn)
+    logger.info(f"Restored archive serial numbers for documents {list(backup.keys())}")
+
+
 def set_correspondent(
     doc_ids: list[int],
     correspondent: Correspondent,
@@ -433,8 +468,6 @@ def merge(
 
     if user is not None:
         overrides.owner_id = user.id
-    # Avoid copying or detecting ASN from merged PDFs to prevent collision
-    overrides.skip_asn = True
 
     logger.info("Adding merged document to the task queue.")
 
@@ -447,10 +480,18 @@ def merge(
     )
 
     if delete_originals:
+        backup = release_archive_serial_numbers(affected_docs)
         logger.info(
             "Queueing removal of original documents after consumption of merged document",
         )
-        chain(consume_task, delete.si(affected_docs)).delay()
+        try:
+            consume_task.apply_async(
+                link=[delete.si(affected_docs)],
+                link_error=[restore_archive_serial_numbers_task.s(backup)],
+            )
+        except Exception:
+            restore_archive_serial_numbers(backup)
+            raise
     else:
         consume_task.delay()
 
@@ -508,10 +549,20 @@ def split(
                 )
 
             if delete_originals:
+                backup = release_archive_serial_numbers([doc.id])
                 logger.info(
                     "Queueing removal of original document after consumption of the split documents",
                 )
-                chord(header=consume_tasks, body=delete.si([doc.id])).delay()
+                try:
+                    chord(
+                        header=consume_tasks,
+                        body=delete.si([doc.id]),
+                    ).apply_async(
+                        link_error=[restore_archive_serial_numbers_task.s(backup)],
+                    )
+                except Exception:
+                    restore_archive_serial_numbers(backup)
+                    raise
             else:
                 group(consume_tasks).delay()
 
@@ -614,7 +665,6 @@ def edit_pdf(
             )
             if user is not None:
                 overrides.owner_id = user.id
-
             for idx, pdf in enumerate(pdf_docs, start=1):
                 filepath: Path = (
                     Path(tempfile.mkdtemp(dir=settings.SCRATCH_DIR))
@@ -633,7 +683,17 @@ def edit_pdf(
                 )
 
             if delete_original:
-                chord(header=consume_tasks, body=delete.si([doc.id])).delay()
+                backup = release_archive_serial_numbers([doc.id])
+                try:
+                    chord(
+                        header=consume_tasks,
+                        body=delete.si([doc.id]),
+                    ).apply_async(
+                        link_error=[restore_archive_serial_numbers_task.s(backup)],
+                    )
+                except Exception:
+                    restore_archive_serial_numbers(backup)
+                    raise
             else:
                 group(consume_tasks).delay()
 

src/documents/tests/test_bulk_edit.py

@@ -602,23 +602,21 @@ class TestPDFActions(DirectoriesMixin, TestCase):
             expected_filename,
         )
         self.assertEqual(consume_file_args[1].title, None)
-        self.assertTrue(consume_file_args[1].skip_asn)
+        self.assertFalse(consume_file_args[1].skip_asn)
 
         # With metadata_document_id overrides
         result = bulk_edit.merge(doc_ids, metadata_document_id=metadata_document_id)
         consume_file_args, _ = mock_consume_file.call_args
         self.assertEqual(consume_file_args[1].title, "B (merged)")
         self.assertEqual(consume_file_args[1].created, self.doc2.created)
-        self.assertTrue(consume_file_args[1].skip_asn)
+        self.assertFalse(consume_file_args[1].skip_asn)
 
         self.assertEqual(result, "OK")
 
     @mock.patch("documents.bulk_edit.delete.si")
     @mock.patch("documents.tasks.consume_file.s")
-    @mock.patch("documents.bulk_edit.chain")
     def test_merge_and_delete_originals(
         self,
-        mock_chain,
         mock_consume_file,
         mock_delete_documents,
     ):
@@ -632,6 +630,12 @@ class TestPDFActions(DirectoriesMixin, TestCase):
             - Document deletion task should be called
         """
         doc_ids = [self.doc1.id, self.doc2.id, self.doc3.id]
+        self.doc1.archive_serial_number = 101
+        self.doc2.archive_serial_number = 102
+        self.doc3.archive_serial_number = 103
+        self.doc1.save()
+        self.doc2.save()
+        self.doc3.save()
 
         result = bulk_edit.merge(doc_ids, delete_originals=True)
         self.assertEqual(result, "OK")
@@ -642,7 +646,8 @@ class TestPDFActions(DirectoriesMixin, TestCase):
 
         mock_consume_file.assert_called()
         mock_delete_documents.assert_called()
-        mock_chain.assert_called_once()
+        consume_sig = mock_consume_file.return_value
+        consume_sig.apply_async.assert_called_once()
 
         consume_file_args, _ = mock_consume_file.call_args
         self.assertEqual(
@@ -650,7 +655,7 @@ class TestPDFActions(DirectoriesMixin, TestCase):
             expected_filename,
         )
         self.assertEqual(consume_file_args[1].title, None)
-        self.assertTrue(consume_file_args[1].skip_asn)
+        self.assertFalse(consume_file_args[1].skip_asn)
 
         delete_documents_args, _ = mock_delete_documents.call_args
         self.assertEqual(
@@ -658,6 +663,13 @@ class TestPDFActions(DirectoriesMixin, TestCase):
             doc_ids,
         )
 
+        self.doc1.refresh_from_db()
+        self.doc2.refresh_from_db()
+        self.doc3.refresh_from_db()
+        self.assertIsNone(self.doc1.archive_serial_number)
+        self.assertIsNone(self.doc2.archive_serial_number)
+        self.assertIsNone(self.doc3.archive_serial_number)
+
     @mock.patch("documents.tasks.consume_file.s")
     def test_merge_with_archive_fallback(self, mock_consume_file):
         """
@@ -726,6 +738,7 @@ class TestPDFActions(DirectoriesMixin, TestCase):
         self.assertEqual(mock_consume_file.call_count, 2)
         consume_file_args, _ = mock_consume_file.call_args
         self.assertEqual(consume_file_args[1].title, "B (split 2)")
+        self.assertFalse(consume_file_args[1].skip_asn)
 
         self.assertEqual(result, "OK")
 
@@ -750,6 +763,8 @@ class TestPDFActions(DirectoriesMixin, TestCase):
         """
         doc_ids = [self.doc2.id]
         pages = [[1, 2], [3]]
+        self.doc2.archive_serial_number = 200
+        self.doc2.save()
 
         result = bulk_edit.split(doc_ids, pages, delete_originals=True)
         self.assertEqual(result, "OK")
@@ -757,6 +772,7 @@ class TestPDFActions(DirectoriesMixin, TestCase):
         self.assertEqual(mock_consume_file.call_count, 2)
         consume_file_args, _ = mock_consume_file.call_args
         self.assertEqual(consume_file_args[1].title, "B (split 2)")
+        self.assertFalse(consume_file_args[1].skip_asn)
 
         mock_delete_documents.assert_called()
         mock_chord.assert_called_once()
@@ -767,6 +783,9 @@ class TestPDFActions(DirectoriesMixin, TestCase):
             doc_ids,
         )
 
+        self.doc2.refresh_from_db()
+        self.assertIsNone(self.doc2.archive_serial_number)
+
     @mock.patch("documents.tasks.consume_file.delay")
     @mock.patch("pikepdf.Pdf.save")
     def test_split_with_errors(self, mock_save_pdf, mock_consume_file):
@@ -967,10 +986,16 @@ class TestPDFActions(DirectoriesMixin, TestCase):
         mock_chord.return_value.delay.return_value = None
         doc_ids = [self.doc2.id]
         operations = [{"page": 1}, {"page": 2}]
+        self.doc2.archive_serial_number = 250
+        self.doc2.save()
 
         result = bulk_edit.edit_pdf(doc_ids, operations, delete_original=True)
         self.assertEqual(result, "OK")
         mock_chord.assert_called_once()
+        consume_file_args, _ = mock_consume_file.call_args
+        self.assertFalse(consume_file_args[1].skip_asn)
+        self.doc2.refresh_from_db()
+        self.assertIsNone(self.doc2.archive_serial_number)
 
     @mock.patch("documents.tasks.update_document_content_maybe_archive_file.delay")
     def test_edit_pdf_with_update_document(self, mock_update_document):