Fix: use a root document's effective content for the LLM index and prompts

The search index and the document views use the newest version's content as a
root document's content, but everything the LLM side reads used the root's own
content: the text embedded in the LLM index, the content in the classification
prompt, the context blocks from similar documents, and the text that is
searched for similar documents. After a document was replaced by a new
version the LLM kept answering from the old text.

Read get_effective_content() in those four places. The index update annotates
the content in the query like the search index does, and the similar-document
lookup annotates it for the documents it fetches, so no query is made per
document. Entries already in the LLM index keep the old text until the
document next changes or the index is rebuilt.

.github/workflows/ci-backend.yml

@@ -80,7 +80,7 @@ jobs:
     needs: changes
     if: needs.changes.outputs.backend_changed == 'true'
     name: "Python ${{ matrix.python-version }}"
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     strategy:
@@ -114,7 +114,7 @@ jobs:
           packages: unpaper tesseract-ocr imagemagick ghostscript poppler-utils
       - name: Configure ImageMagick
         run: |
-          sudo cp docker/rootfs/etc/ImageMagick-6/paperless-policy.xml /etc/ImageMagick-6/policy.xml
+          sudo cp docker/rootfs/etc/ImageMagick-6/paperless-policy.xml /etc/ImageMagick-7/policy.xml
       - name: Install Python dependencies
         env:
           PYTHON_VERSION: ${{ steps.setup-python.outputs.python-version }}
@@ -158,7 +158,7 @@ jobs:
     needs: changes
     if: needs.changes.outputs.backend_changed == 'true'
     name: Check project typing
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     env:

.github/workflows/ci-docker.yml

@@ -24,10 +24,10 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - runner: ubuntu-24.04
+          - runner: ubuntu-26.04
             arch: amd64
             platform: linux/amd64
-          - runner: ubuntu-24.04-arm
+          - runner: ubuntu-26.04-arm
             arch: arm64
             platform: linux/arm64
     runs-on: ${{ matrix.runner }}
@@ -163,7 +163,7 @@ jobs:
           archive: false
   merge-and-push:
     name: Merge and Push Manifest
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     needs: build-arch
     if: needs.build-arch.outputs.should-push == 'true'
     environment: image-publishing

.github/workflows/ci-docs.yml

@@ -65,7 +65,7 @@ jobs:
     needs: changes
     if: needs.changes.outputs.docs_changed == 'true'
     name: Build Documentation
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - uses: actions/configure-pages@45bfe0192ca1faeb007ade9deae92b16b8254a0d # v6.0.0
       - name: Checkout
@@ -102,7 +102,7 @@ jobs:
     name: Deploy Documentation
     needs: [changes, build]
     if: github.event_name == 'push' && github.ref == 'refs/heads/main' && needs.changes.outputs.docs_changed == 'true'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       pages: write
       id-token: write

.github/workflows/ci-frontend.yml

@@ -72,7 +72,7 @@ jobs:
     needs: changes
     if: needs.changes.outputs.frontend_changed == 'true'
     name: Install Dependencies
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     steps:
@@ -104,7 +104,7 @@ jobs:
     name: Lint
     needs: [changes, install-dependencies]
     if: needs.changes.outputs.frontend_changed == 'true'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     steps:
@@ -137,7 +137,7 @@ jobs:
     name: "Unit Tests (${{ matrix.shard-index }}/${{ matrix.shard-count }})"
     needs: [changes, install-dependencies]
     if: needs.changes.outputs.frontend_changed == 'true'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     strategy:
@@ -188,10 +188,10 @@ jobs:
     name: E2E Tests
     needs: [changes, install-dependencies]
     if: needs.changes.outputs.frontend_changed == 'true'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
-    container: mcr.microsoft.com/playwright:v1.62.1-noble
+    container: mcr.microsoft.com/playwright:v1.62.1-resolute
     env:
       PLAYWRIGHT_BROWSERS_PATH: /ms-playwright
       PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD: 1
@@ -246,7 +246,7 @@ jobs:
     name: Frontend Build
     needs: [changes, unit-tests, e2e-tests]
     if: needs.changes.outputs.frontend_changed == 'true'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     steps:

.github/workflows/ci-release.yml

@@ -14,7 +14,7 @@ permissions: {}
 jobs:
   wait-for-docker:
     name: Wait for Docker Build
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       checks: read
       statuses: read
@@ -30,7 +30,7 @@ jobs:
   build-release:
     name: Build Release
     needs: wait-for-docker
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
     steps:
@@ -73,7 +73,7 @@ jobs:
         timeout-minutes: 12
         uses: $/.github/actions/apt-install
         with:
-          packages: gettext liblept5
+          packages: gettext libleptonica6
       # ---- Build Documentation ----
       - name: Build documentation
         env:
@@ -145,7 +145,7 @@ jobs:
   publish-release:
     name: Publish Release
     needs: build-release
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: write
       pull-requests: write
@@ -197,7 +197,7 @@ jobs:
     name: Append Changelog
     needs: publish-release
     if: needs.publish-release.outputs.prerelease == 'false'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: write
       pull-requests: write

.github/workflows/ci-static-analysis.yml

@@ -15,7 +15,7 @@ permissions:
 jobs:
   zizmor:
     name: Run zizmor
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       contents: read
       actions: read
@@ -29,7 +29,7 @@ jobs:
         uses: zizmorcore/zizmor-action@cc914d7f3750a2d13d75c7f184a1060aa0e9d482 # v0.6.4
   semgrep:
     name: Semgrep CE
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     container:
       image: semgrep/semgrep:1.155.0@sha256:cc869c685dcc0fe497c86258da9f205397d8108e56d21a86082ea4886e52784d
     if: github.actor != 'dependabot[bot]'

.github/workflows/cleanup-tags.yml

@@ -17,7 +17,7 @@ jobs:
   cleanup-images:
     name: Cleanup Image Tags for ${{ matrix.primary-name }}
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     environment: registry-maintenance
     strategy:
       fail-fast: false
@@ -42,7 +42,7 @@ jobs:
   cleanup-untagged-images:
     name: Cleanup Untagged Images Tags for ${{ matrix.primary-name }}
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     needs:
       - cleanup-images
     environment: registry-maintenance

.github/workflows/codeql-analysis.yml

@@ -21,7 +21,7 @@ on:
 jobs:
   analyze:
     name: Analyze
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       actions: read
       contents: read

.github/workflows/crowdin.yml

@@ -13,7 +13,7 @@ jobs:
   synchronize-with-crowdin:
     name: Crowdin Sync
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     environment: translation-sync
     steps:
       - name: Checkout

.github/workflows/issue-bot.yml

@@ -7,7 +7,7 @@ jobs:
     # Note: peakoss/anti-slop does not support the `issues` event yet (all of its
     # issue inputs are still commented out upstream), so the checks that the PR Bot
     # workflow gets from the action are implemented manually here.
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     permissions:
       issues: write
     steps:

.github/workflows/pr-bot.yml

@@ -4,7 +4,7 @@ on:
     types: [opened]
 jobs:
   Anti-slop:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     permissions:
       contents: read
       issues: read
@@ -24,7 +24,7 @@ jobs:
             ASLOP-PR-VERIFY
   pr-bot:
     name: Automated PR Bot
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     # Runs after Anti-slop so the welcome comment can see whether the PR was closed
     # instead of racing it. Still runs if that job fails, so labeling is not lost.
     needs: Anti-slop

.github/workflows/project-actions.yml

@@ -12,7 +12,7 @@ permissions:
 jobs:
   pr_opened_or_reopened:
     name: pr_opened_or_reopened
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-slim
     permissions:
       # write permission is required for autolabeler
       pull-requests: write

.github/workflows/repo-maintenance.yml

@@ -9,7 +9,7 @@ jobs:
   stale:
     name: 'Stale'
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       issues: write
       pull-requests: write
@@ -34,7 +34,7 @@ jobs:
   lock-threads:
     name: 'Lock Old Threads'
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     permissions:
       issues: write
       pull-requests: write
@@ -58,7 +58,7 @@ jobs:
   close-answered-discussions:
     name: 'Close Answered Discussions'
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-slim
     permissions:
       discussions: write
     steps:
@@ -117,7 +117,7 @@ jobs:
   close-outdated-discussions:
     name: 'Close Outdated Discussions'
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-slim
     permissions:
       discussions: write
     steps:
@@ -211,7 +211,7 @@ jobs:
   close-unsupported-feature-requests:
     name: 'Close Unsupported Feature Requests'
     if: github.repository_owner == 'paperless-ngx'
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-slim
     permissions:
       discussions: write
     steps:

.github/workflows/translate-strings.yml

@@ -8,7 +8,7 @@ env:
 jobs:
   generate-translate-strings:
     name: Generate Translation Strings
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     environment: translation-sync
     permissions:
       contents: write

src/documents/bulk_edit.py

@@ -13,8 +13,14 @@ from celery import group
 from celery import shared_task
 from django.conf import settings
 from django.db import transaction
+from django.db.models import Case
+from django.db.models import F
 from django.db.models import Max
+from django.db.models import OuterRef
 from django.db.models import Q
+from django.db.models import Subquery
+from django.db.models import When
+from django.db.models.functions import Coalesce
 from django.utils import timezone
 
 from documents.data_models import ConsumableDocument
@@ -36,6 +42,7 @@ from documents.tasks import remove_document_from_index
 from documents.tasks import update_document_content_maybe_archive_file
 from documents.versioning import get_latest_version_for_root
 from documents.versioning import get_root_document
+from documents.versioning import versions_newest_first
 
 if TYPE_CHECKING:
     from collections.abc import Mapping
@@ -408,10 +415,28 @@ def reprocess(doc_ids: list[int], *, remote_ocr: bool = False) -> Literal["OK"]:
 
     Consumption workflows do not run here, so ``remote_ocr`` is how the user
     asks for the remote engine when it is not configured to handle everything.
+
+    A root document with versions reprocesses its latest version, which is the
+    file whose content, archive and thumbnail are shown for it.
     """
-    for document_id in doc_ids:
+    latest_version = versions_newest_first(
+        Document.objects.filter(root_document=OuterRef("pk")),
+    ).values("id")[:1]
+    source_ids = (
+        Document.objects.filter(id__in=doc_ids)
+        .annotate(
+            source_id=Case(
+                When(root_document__isnull=False, then=F("id")),
+                default=Coalesce(Subquery(latest_version), F("id")),
+            ),
+        )
+        .order_by()
+        .values_list("source_id", flat=True)
+        .distinct()
+    )
+    for source_id in source_ids:
         update_document_content_maybe_archive_file.apply_async(
-            kwargs={"document_id": document_id, "remote_ocr": remote_ocr},
+            kwargs={"document_id": source_id, "remote_ocr": remote_ocr},
             headers={"trigger_source": PaperlessTask.TriggerSource.MANUAL},
         )
 

src/documents/management/commands/document_index.py

@@ -67,18 +67,22 @@ class Command(PaperlessCommand):
                 if options.get("recreate"):
                     wipe_index(settings.INDEX_DIR)
 
-                documents = Document.objects.select_related(
-                    "correspondent",
-                    "document_type",
-                    "storage_path",
-                    "owner",
-                ).prefetch_related(
-                    "tags",
-                    "notes__user",
-                    "custom_fields__field",
-                    "versions",
-                    "barcodes",
-                    "versions__barcodes",
+                documents = (
+                    Document.objects.filter(root_document__isnull=True)
+                    .select_related(
+                        "correspondent",
+                        "document_type",
+                        "storage_path",
+                        "owner",
+                    )
+                    .prefetch_related(
+                        "tags",
+                        "notes__user",
+                        "custom_fields__field",
+                        "versions",
+                        "barcodes",
+                        "versions__barcodes",
+                    )
                 )
                 total = documents.count()
                 rebuild_kwargs = {}

src/documents/permissions.py

@@ -6,14 +6,19 @@ from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
 from django.db.models import Case
+from django.db.models import CharField
 from django.db.models import Count
+from django.db.models import Exists
+from django.db.models import F
 from django.db.models import IntegerField
 from django.db.models import Model
+from django.db.models import OuterRef
 from django.db.models import Q
 from django.db.models import QuerySet
 from django.db.models import Value
 from django.db.models import When
 from django.db.models.functions import Cast
+from django.db.models.functions import Coalesce
 from guardian.core import ObjectPermissionChecker
 from guardian.models import GroupObjectPermission
 from guardian.models import UserObjectPermission
@@ -25,6 +30,7 @@ from rest_framework.permissions import BasePermission
 from rest_framework.permissions import DjangoObjectPermissions
 
 from documents.models import Document
+from documents.versioning import get_root_document
 
 
 class PaperlessObjectPermissions(DjangoObjectPermissions):
@@ -348,6 +354,7 @@ def permitted_object_ids(
     perm: str,
     *,
     include_deleted: bool = False,
+    parent_field: str | None = None,
 ) -> QuerySet[int]:
     """
     Generic version of ``permitted_document_ids`` for any model with an
@@ -356,6 +363,20 @@ def permitted_object_ids(
     soft-delete pattern (currently only ``Document``); for every other model
     it is accepted but has no effect, since those models have no soft-delete
     concept.
+
+    ``parent_field`` names a self-referencing foreign key whose target
+    authorizes the row (``Document.root_document``). A row with a parent is
+    visible exactly when its parent is, judged by the parent's owner and
+    grants, so the row's own owner and grants are ignored.
+
+    Guardian stores ``object_pk`` as a string, so each grant is an ``EXISTS``
+    keyed on the row's id cast to a string, which can use guardian's
+    (user, permission, object_pk) unique index. Casting every ``object_pk`` to
+    an integer for an ``id IN (...)`` is not indexable, and MariaDB cannot
+    materialize it inside the owner ``OR``, so it re-scans the user's grants
+    for every row. The user's groups are matched with an ``IN`` subquery
+    rather than a join through the membership table, which SQLite plans badly
+    once the grant tables grow.
     """
     has_soft_delete = hasattr(model, "global_objects")
     manager = (
@@ -363,8 +384,21 @@ def permitted_object_ids(
     )
     base_qs = manager.all().only("id", "owner")
 
+    owner_field, key_field = "owner", "pk"
+    if parent_field is not None:
+        owner_field, key_field = "authorizing_owner", "authorizing_id"
+        base_qs = base_qs.annotate(
+            authorizing_id=Coalesce(f"{parent_field}_id", "id"),
+            authorizing_owner=Case(
+                When(**{f"{parent_field}_id__isnull": True}, then=F("owner_id")),
+                default=F(f"{parent_field}__owner_id"),
+                output_field=IntegerField(),
+            ),
+        )
+    unowned = Q(**{f"{owner_field}__isnull": True})
+
     if user is None or not getattr(user, "is_authenticated", False):
-        return base_qs.filter(owner__isnull=True).values_list("id", flat=True)
+        return base_qs.filter(unowned).values_list("id", flat=True)
 
     # Deactivated users get nothing, deactivated superusers included, so this
     # has to come before the superuser shortcut. guardian's
@@ -388,20 +422,24 @@ def permitted_object_ids(
         "permission__content_type": content_type,
     }
 
-    user_perm_ids = (
-        UserObjectPermission.objects.filter(user=user, **perm_filter)
-        .annotate(object_pk_int=Cast("object_pk", IntegerField()))
-        .values_list("object_pk_int", flat=True)
+    key_as_text = Cast(OuterRef(key_field), CharField(max_length=64))
+    granted_to_user = Exists(
+        UserObjectPermission.objects.filter(
+            user=user,
+            object_pk=key_as_text,
+            **perm_filter,
+        ),
     )
-    group_perm_ids = (
-        GroupObjectPermission.objects.filter(group__user=user, **perm_filter)
-        .annotate(object_pk_int=Cast("object_pk", IntegerField()))
-        .values_list("object_pk_int", flat=True)
+    granted_to_group = Exists(
+        GroupObjectPermission.objects.filter(
+            group_id__in=user.groups.values("id"),
+            object_pk=key_as_text,
+            **perm_filter,
+        ),
     )
-    permitted_ids = user_perm_ids.union(group_perm_ids)
 
     return base_qs.filter(
-        Q(owner=user) | Q(owner__isnull=True) | Q(id__in=permitted_ids),
+        Q(**{owner_field: user.pk}) | unowned | granted_to_user | granted_to_group,
     ).values_list("id", flat=True)
 
 
@@ -470,8 +508,17 @@ def permitted_document_ids(
     ``include_deleted=True`` for callers that need to check permission on
     soft-deleted documents (e.g. trash restore). This intentionally avoids
     ``get_objects_for_user`` to keep the subquery small and index-friendly.
+
+    A version is authorized by its root document, so a version's own owner and
+    grants never matter.
     """
-    return permitted_object_ids(user, Document, perm, include_deleted=include_deleted)
+    return permitted_object_ids(
+        user,
+        Document,
+        perm,
+        include_deleted=include_deleted,
+        parent_field="root_document",
+    )
 
 
 def get_document_count_filter_for_user(user, related_name: str = "documents"):
@@ -630,7 +677,14 @@ def has_perms_owner_aware(user, perms, obj):
     single-object check still has many production callers. Several callers
     remain across ``documents/``, ``paperless_mail/``, and ``paperless_ai/``
     -- grep for this function name before removing it.
+
+    A document version is authorized by its root document, like in
+    ``permitted_document_ids``, so a version's own owner and grants never
+    matter. Fetch the root with ``select_related("root_document__owner")`` to
+    avoid extra queries.
     """
+    if isinstance(obj, Document):
+        obj = get_root_document(obj)
     checker = ObjectPermissionChecker(user)
     return obj.owner is None or obj.owner == user or checker.has_perm(perms, obj)
 

src/documents/search/_backend.py

@@ -7,6 +7,7 @@ import threading
 import time
 from datetime import UTC
 from datetime import datetime
+from datetime import timedelta
 from enum import StrEnum
 from itertools import islice
 from typing import TYPE_CHECKING
@@ -31,6 +32,7 @@ from documents.search._query import parse_user_query
 from documents.search._schema import _write_sentinels
 from documents.search._schema import build_schema
 from documents.search._schema import open_or_rebuild_index
+from documents.search._schema import rebuild_in_progress
 from documents.search._schema import wipe_index
 from documents.search._tokenizer import ascii_fold
 from documents.search._tokenizer import autocomplete_tokens
@@ -54,6 +56,19 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger("paperless.search")
 
+# tantivy stores dates as signed 64-bit nanoseconds since the Unix epoch, which
+# covers 1677-09-21T00:12:43 to 2262-04-11T23:47:16 UTC
+_INDEX_DATE_NANOS_MIN: Final[int] = -(2**63)
+_INDEX_DATE_NANOS_MAX: Final[int] = 2**63 - 1
+_UNIX_EPOCH: Final[datetime] = datetime(1970, 1, 1, tzinfo=UTC)
+
+
+def _is_indexable_date(value: datetime) -> bool:
+    """Whether value, at whole-second precision, fits tantivy's date range."""
+    nanos = ((value - _UNIX_EPOCH) // timedelta(seconds=1)) * 1_000_000_000
+    return _INDEX_DATE_NANOS_MIN <= nanos <= _INDEX_DATE_NANOS_MAX
+
+
 _LOCK_TIMEOUT_SECONDS: Final[float] = 10.0  # per-attempt acquire timeout
 _LOCK_RETRY_ATTEMPTS: Final[int] = 4  # total attempts (1 initial + 3 retries)
 _LOCK_BACKOFF_BASE: Final[float] = 1.0  # seconds
@@ -269,9 +284,14 @@ class WriteBatch:
         and adding the new version. This ensures stale document data (e.g., after
         permission changes) doesn't persist in the index.
 
+        Only root documents are indexed, with their effective content, so a
+        version is indexed as its root document.
+
         Args:
             document: Django Document instance to index
         """
+        if document.root_document_id is not None:
+            document = document.root_document
         self.remove(document.pk)
         doc = self._backend._build_tantivy_doc(document)
         self._writer.add_document(doc)
@@ -296,20 +316,22 @@ class WriteBatch:
         An id with no matching document (e.g. deleted between the caller
         collecting ids and the batch running) is silently skipped, matching
         ``add_or_update()``'s existing single-document deferred-task behavior
-        rather than erroring or leaving a stale index entry.
+        rather than erroring or leaving a stale index entry. The id of a
+        version stands for its root document.
 
         Args:
             ids: Primary keys of Document instances to index
         """
         from documents.models import Document
         from documents.versioning import annotate_effective_content
+        from documents.versioning import root_document_ids
 
         ids = list(ids)
         if not ids:
             return
 
         queryset = annotate_effective_content(
-            Document.objects.filter(pk__in=ids)
+            Document.objects.filter(pk__in=root_document_ids(ids))
             .select_related("correspondent", "document_type", "storage_path", "owner")
             .prefetch_related(
                 "tags",
@@ -627,7 +649,15 @@ class TantivyBackend:
             document.created.day,
             tzinfo=UTC,
         )
-        doc.add_date("created", created_date)
+        if _is_indexable_date(created_date):
+            doc.add_date("created", created_date)
+        else:
+            logger.warning(
+                "Document %s has a created date (%s) outside the range the search "
+                "index can store; it will be indexed without a created date",
+                document.pk,
+                document.created,
+            )
         doc.add_date("modified", document.modified)
         doc.add_date("added", document.added)
 
@@ -1110,39 +1140,44 @@ class TantivyBackend:
                 flushing a segment, deferring merge work; they do not avoid it.
         """
         wipe_index(self._path)
-        new_index = tantivy.Index(build_schema(), path=str(self._path))
-        _write_sentinels(self._path)
-        register_tokenizers(new_index, settings.SEARCH_LANGUAGE)
+        # The marker covers the window where the empty index is already stamped
+        # as current but not yet populated, so an interrupted rebuild is retried.
+        with rebuild_in_progress(self._path):
+            new_index = tantivy.Index(build_schema(), path=str(self._path))
+            _write_sentinels(self._path)
+            register_tokenizers(new_index, settings.SEARCH_LANGUAGE)
 
-        # Point instance at the new index so _build_tantivy_doc uses it
-        old_index, old_schema = self._raw_index, self._raw_schema
-        self._raw_index = new_index
-        self._raw_schema = new_index.schema
-        # Stream documents one-by-one (so the progress bar advances per
-        # document) while fetching viewer permissions one SQL query per chunk.
-        # The stream is Sized, so iter_wrapper can still discover the total.
-        documents_stream = _DocumentViewerStream(documents, chunk_size=1000)
-        try:
-            writer = new_index.writer(heap_size=writer_heap_bytes)
-            for document, (viewer_ids, viewer_group_ids) in iter_wrapper(
-                documents_stream,
-            ):
-                doc = self._build_tantivy_doc(
-                    document,
-                    viewer_ids=viewer_ids,
-                    viewer_group_ids=viewer_group_ids,
-                )
-                writer.add_document(doc)
-            writer.commit()
-            # Wait for background merge threads to finish so all segments are
-            # fully merged and persisted before the index is considered rebuilt.
-            writer.wait_merging_threads()
-            new_index.reload()
-        except BaseException:  # pragma: no cover
-            # Restore old index on failure so the backend remains usable
-            self._raw_index = old_index
-            self._raw_schema = old_schema
-            raise
+            # Point instance at the new index so _build_tantivy_doc uses it
+            old_index, old_schema = self._raw_index, self._raw_schema
+            self._raw_index = new_index
+            self._raw_schema = new_index.schema
+            # Stream documents one-by-one (so the progress bar advances per
+            # document) while fetching viewer permissions one SQL query per
+            # chunk. The stream is Sized, so iter_wrapper can still discover
+            # the total.
+            documents_stream = _DocumentViewerStream(documents, chunk_size=1000)
+            try:
+                writer = new_index.writer(heap_size=writer_heap_bytes)
+                for document, (viewer_ids, viewer_group_ids) in iter_wrapper(
+                    documents_stream,
+                ):
+                    doc = self._build_tantivy_doc(
+                        document,
+                        viewer_ids=viewer_ids,
+                        viewer_group_ids=viewer_group_ids,
+                    )
+                    writer.add_document(doc)
+                writer.commit()
+                # Wait for background merge threads to finish so all segments
+                # are fully merged and persisted before the index is considered
+                # rebuilt.
+                writer.wait_merging_threads()
+                new_index.reload()
+            except BaseException:  # pragma: no cover
+                # Restore old index on failure so the backend remains usable
+                self._raw_index = old_index
+                self._raw_schema = old_schema
+                raise
 
 
 def chunked(iterable, size):

src/documents/search/_schema.py

@@ -4,6 +4,7 @@ import hashlib
 import json
 import logging
 import shutil
+from contextlib import contextmanager
 from typing import TYPE_CHECKING
 from typing import Final
 from typing import NamedTuple
@@ -16,6 +17,7 @@ from whoosh_compat import FieldKind
 from documents.search._fields import PUBLIC_FIELDS
 
 if TYPE_CHECKING:
+    from collections.abc import Iterator
     from pathlib import Path
 
 logger = logging.getLogger("paperless.search")
@@ -28,6 +30,11 @@ logger = logging.getLogger("paperless.search")
 # v3 - barcodes JSON field for stored barcode contents
 SCHEMA_VERSION: Final[int] = 3
 
+# Present in the index directory from the moment a full rebuild starts until it
+# finishes. If a rebuild is interrupted it is left behind, so the half-built
+# index is not mistaken for a complete one.
+REBUILD_MARKER: Final[str] = ".rebuilding"
+
 
 class FieldDescriptor(NamedTuple):
     """One tantivy field, in declaration order.
@@ -255,9 +262,9 @@ def needs_rebuild(index_dir: Path) -> bool:
     """
     Check if the search index needs rebuilding.
 
-    Reads .index_settings.json to compare the stored schema version, search
-    language and schema fingerprint against the current configuration. Returns
-    True if the file is missing, unparsable, or any value mismatches.
+    True if a previous full rebuild never finished (the rebuild marker is still
+    present), or if the index's stamped settings no longer match the current
+    configuration. See _settings_mismatch().
 
     Args:
         index_dir: Path to the search index directory
@@ -265,6 +272,40 @@ def needs_rebuild(index_dir: Path) -> bool:
     Returns:
         True if the index needs rebuilding, False if it's up to date
     """
+    if (index_dir / REBUILD_MARKER).exists():
+        logger.warning("Previous search index rebuild did not finish - rebuilding.")
+        return True
+    return _settings_mismatch(index_dir)
+
+
+@contextmanager
+def rebuild_in_progress(index_dir: Path) -> Iterator[None]:
+    """
+    Flag the index as incomplete for the duration of a full rebuild.
+
+    The marker is cleared only if the block exits cleanly. There is deliberately
+    no try/finally: an exception must leave the marker behind so the next
+    needs_rebuild() check retries the rebuild.
+    """
+    marker = index_dir / REBUILD_MARKER
+    marker.touch()
+    yield
+    marker.unlink(missing_ok=True)
+
+
+def _settings_mismatch(index_dir: Path) -> bool:
+    """
+    Check the stamped settings against the current configuration.
+
+    Reads .index_settings.json to compare the stored schema version, search
+    language and schema fingerprint. Returns True if the file is missing,
+    unparsable, or any value mismatches.
+
+    This deliberately ignores the rebuild marker: open_or_rebuild_index() uses it
+    so that a process opening the index while another process is mid-rebuild
+    (or after one died) does not wipe the partial index out from under it.
+    Repopulating is the job of ``document_index reindex``.
+    """
     settings_file = index_dir / ".index_settings.json"
     if not settings_file.exists():
         return True
@@ -333,7 +374,7 @@ def open_or_rebuild_index(index_dir: Path | None = None) -> tantivy.Index:
         index_dir = cast("Path", settings.INDEX_DIR)
     if not index_dir.exists():
         return tantivy.Index(build_schema())
-    if needs_rebuild(index_dir):
+    if _settings_mismatch(index_dir):
         wipe_index(index_dir)
         idx = tantivy.Index(build_schema(), path=str(index_dir))
         _write_sentinels(index_dir)

src/documents/tasks.py

@@ -502,6 +502,8 @@ def update_document_content_maybe_archive_file(
                 llm_index_add_or_update_document(document)
 
             clear_document_caches(document.pk)
+            if document.root_document_id is not None:
+                clear_document_caches(document.root_document_id)
 
         except Exception:
             logger.exception(

src/documents/tests/search/test_backend.py

@@ -1,4 +1,6 @@
 import json
+import logging
+from datetime import date
 from pathlib import Path
 
 import pytest
@@ -16,7 +18,10 @@ from documents.search._backend import TantivyBackend
 from documents.search._backend import WriteBatch
 from documents.search._backend import get_backend
 from documents.search._backend import reset_backend
+from documents.search._schema import REBUILD_MARKER
+from documents.search._schema import needs_rebuild
 from documents.signals.handlers import add_to_index
+from paperless_testing.dirs import PaperlessDirs
 from paperless_testing.factories import CorrespondentFactory
 from paperless_testing.factories import DocumentFactory
 from paperless_testing.factories import DocumentTypeFactory
@@ -288,6 +293,80 @@ class TestAddOrUpdateIds:
         assert backend.search_ids("updated", user=None) == [doc.pk]
 
 
+class TestVersionsAreIndexedAsTheirRoot:
+    """Only root documents are indexed, with their effective content, so
+    every write path that is handed a version indexes its root instead."""
+
+    @staticmethod
+    def _root_with_version() -> tuple[Document, Document]:
+        root = DocumentFactory(title="Statement", content="stale text")
+        version = DocumentFactory(
+            title="Statement",
+            content="latest text",
+            root_document=root,
+            version_index=1,
+        )
+        return root, version
+
+    def test_add_or_update_indexes_the_root_of_a_version(
+        self,
+        backend: TantivyBackend,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - The version is passed to add_or_update
+        THEN:
+            - The root is indexed with the version's text, and the version is not
+        """
+        root, version = self._root_with_version()
+
+        backend.add_or_update(version)
+
+        assert backend.search_ids("latest", user=None) == [root.pk]
+        assert backend.search_ids("stale", user=None) == []
+
+    def test_add_or_update_ids_indexes_each_root_once(
+        self,
+        backend: TantivyBackend,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - Both ids are passed to add_or_update_ids
+        THEN:
+            - The root is indexed once and the version is not indexed
+        """
+        root, version = self._root_with_version()
+
+        with backend.batch_update() as batch:
+            batch.add_or_update_ids([version.pk, root.pk])
+
+        assert backend.search_ids("Statement", user=None) == [root.pk]
+        assert backend.search_ids("latest", user=None) == [root.pk]
+
+    def test_add_or_update_ids_resolves_a_lone_version(
+        self,
+        backend: TantivyBackend,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - Only the version's id is passed to add_or_update_ids
+        THEN:
+            - The root is indexed
+        """
+        root, version = self._root_with_version()
+
+        with backend.batch_update() as batch:
+            batch.add_or_update_ids([version.pk])
+
+        assert backend.search_ids("latest", user=None) == [root.pk]
+
+
 class TestSearch:
     """Test search query parsing and matching via search_ids."""
 
@@ -823,6 +902,53 @@ class TestRebuild:
         backend.rebuild(Document.objects.all(), iter_wrapper=wrapper)
         assert 30 in seen
 
+    def test_successful_rebuild_leaves_index_up_to_date(
+        self,
+        backend: TantivyBackend,
+        paperless_dirs: PaperlessDirs,
+    ) -> None:
+        """
+        GIVEN:
+            - A backend and one document
+        WHEN:
+            - rebuild() completes
+        THEN:
+            - needs_rebuild() is False and no rebuild marker remains
+        """
+        DocumentFactory.create()
+
+        backend.rebuild(Document.objects.all())
+
+        assert needs_rebuild(paperless_dirs.index_dir) is False
+        assert not (paperless_dirs.index_dir / REBUILD_MARKER).exists()
+
+    def test_interrupted_rebuild_is_retried(
+        self,
+        backend: TantivyBackend,
+        paperless_dirs: PaperlessDirs,
+    ) -> None:
+        """
+        GIVEN:
+            - A rebuild that dies while indexing documents (e.g. the database
+              connection is lost)
+        WHEN:
+            - needs_rebuild() is checked afterwards
+        THEN:
+            - It is True, even though the empty index was already stamped with
+              current settings, so the next start rebuilds instead of reporting
+              the index as up to date
+        """
+        DocumentFactory.create()
+
+        def die(pairs):
+            raise RuntimeError("terminating connection due to administrator command")
+            yield  # pragma: no cover
+
+        with pytest.raises(RuntimeError):
+            backend.rebuild(Document.objects.all(), iter_wrapper=die)
+
+        assert needs_rebuild(paperless_dirs.index_dir) is True
+
     def test_includes_group_granted_viewers(self, backend: TantivyBackend) -> None:
         """Rebuild must index viewer ids for group-only grants, not just direct ones.
 
@@ -854,6 +980,79 @@ class TestRebuild:
         assert ids == [doc.pk]
 
 
+class TestCreatedDateOutOfRange:
+    """The index stores dates as nanosecond i64 values (1677-09-22 to 2262-04-11).
+
+    A document whose created date falls outside that window must not abort
+    indexing: it is indexed without a created value and a warning names it.
+    """
+
+    @pytest.mark.parametrize(
+        ("created", "expected_warnings"),
+        [
+            pytest.param(date(1677, 9, 22), 0, id="first-representable-day"),
+            pytest.param(date(2262, 4, 11), 0, id="last-representable-day"),
+            pytest.param(date(1677, 9, 21), 1, id="day-before-first"),
+            pytest.param(date(2262, 4, 12), 1, id="day-after-last"),
+            pytest.param(date(16, 8, 30), 1, id="two-digit-year-read-as-year-16"),
+            pytest.param(date(9999, 12, 31), 1, id="max-python-date"),
+        ],
+    )
+    def test_add_or_update_indexes_document_and_warns_when_out_of_range(
+        self,
+        backend: TantivyBackend,
+        caplog: pytest.LogCaptureFixture,
+        created: date,
+        expected_warnings: int,
+    ) -> None:
+        """
+        GIVEN:
+            - A document with a created date at or beyond the index date limits
+        WHEN:
+            - The document is added to the index
+        THEN:
+            - The document is indexed and searchable either way
+            - A warning naming the document is logged only for out-of-range dates
+        """
+        doc = DocumentFactory(created=created, content="boundarycontent")
+
+        with caplog.at_level(logging.WARNING, logger="paperless.search"):
+            backend.add_or_update(doc)
+
+        assert backend.search_ids("boundarycontent", user=None) == [doc.pk]
+        warnings = [r for r in caplog.records if r.levelno == logging.WARNING]
+        assert len(warnings) == expected_warnings
+        if expected_warnings:
+            assert f"Document {doc.pk}" in warnings[0].getMessage()
+
+    def test_rebuild_continues_past_out_of_range_document(
+        self,
+        backend: TantivyBackend,
+        caplog: pytest.LogCaptureFixture,
+    ) -> None:
+        """
+        GIVEN:
+            - A document with an unrepresentable created date among valid ones
+        WHEN:
+            - The index is rebuilt
+        THEN:
+            - Rebuild completes and every document is searchable
+            - A warning names the offending document
+        """
+        good = DocumentFactory(created=date(2016, 8, 30), content="rebuildcontent")
+        bad = DocumentFactory(created=date(16, 8, 30), content="rebuildcontent")
+
+        with caplog.at_level(logging.WARNING, logger="paperless.search"):
+            backend.rebuild(Document.objects.all())
+
+        assert sorted(backend.search_ids("rebuildcontent", user=None)) == sorted(
+            [good.pk, bad.pk],
+        )
+        warnings = [r for r in caplog.records if r.levelno == logging.WARNING]
+        assert len(warnings) == 1
+        assert f"Document {bad.pk}" in warnings[0].getMessage()
+
+
 class TestAutocomplete:
     """Test autocomplete functionality."""
 

src/documents/tests/test_api_document_versions.py

@@ -8,6 +8,7 @@ from auditlog.models import LogEntry  # type: ignore[import-untyped]
 from django.contrib.contenttypes.models import ContentType
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.test import TestCase as DjangoTestCase
+from django.test import override_settings
 from django.utils import timezone
 from rest_framework import status
 from rest_framework.test import APITestCase
@@ -16,13 +17,17 @@ from documents.data_models import DocumentSource
 from documents.filters import EffectiveContentFilter
 from documents.filters import TitleContentFilter
 from documents.models import Document
+from documents.models import Note
+from documents.models import ShareLink
 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_all_global
 from paperless_testing.permissions import grant_global
+from paperless_testing.permissions import grant_object
 
 if TYPE_CHECKING:
     from pathlib import Path
@@ -1043,3 +1048,152 @@ class TestBulkSelectionExcludesVersions(DjangoTestCase):
         )
 
         self.assertEqual(selected, [root.id])
+
+
+class TestVersionActionPermissions(DirectoriesMixin, APITestCase):
+    def setUp(self):
+        super().setUp()
+        self.user = UserFactory()
+        grant_all_global(self.user)
+        self.client.force_authenticate(self.user)
+        self.root = DocumentFactory(owner=UserFactory())
+        self.version = DocumentFactory(root_document=self.root, owner=None)
+
+    @override_settings(AUDIT_LOG_ENABLED=True)
+    def test_actions_reject_stale_version_ownership(self):
+        note = Note.objects.create(document=self.version, note="Version note")
+        for owner in (None, self.user):
+            self.version.owner = owner
+            self.version.save(update_fields=["owner"])
+            for action in (
+                "notes",
+                "suggestions",
+                "ai_suggestions",
+                "history",
+                "share_links",
+            ):
+                with self.subTest(owner=owner, action=action):
+                    response = self.client.get(
+                        f"/api/documents/{self.version.pk}/{action}/",
+                    )
+                    self.assertEqual(response.status_code, 403)
+            response = self.client.post(
+                f"/api/documents/{self.version.pk}/notes/",
+                {"note": "New note"},
+            )
+            self.assertEqual(response.status_code, 403)
+            response = self.client.delete(
+                f"/api/documents/{self.version.pk}/notes/?id={note.pk}",
+            )
+            self.assertEqual(response.status_code, 403)
+            response = self.client.post(
+                "/api/share_links/",
+                {"document": self.version.pk, "file_version": "original"},
+            )
+            self.assertEqual(response.status_code, 403)
+            response = self.client.post(
+                "/api/share_link_bundles/",
+                {"document_ids": [self.version.pk], "file_version": "original"},
+                format="json",
+            )
+            self.assertEqual(response.status_code, 400)
+            response = self.client.post(
+                "/api/documents/email/",
+                {
+                    "documents": [self.version.pk],
+                    "addresses": "recipient@example.com",
+                    "subject": "Version",
+                    "message": "Version",
+                },
+                format="json",
+            )
+            self.assertEqual(response.status_code, 403)
+            with (
+                mock.patch("documents.views.AIConfig") as ai_config,
+                mock.patch("documents.views.stream_chat_with_documents") as chat,
+            ):
+                ai_config.return_value.ai_enabled = True
+                response = self.client.post(
+                    "/api/documents/chat/",
+                    {"q": "Version?", "document_id": self.version.pk},
+                    format="json",
+                )
+            self.assertEqual(response.status_code, 403)
+            chat.assert_not_called()
+        self.assertTrue(Note.objects.filter(pk=note.pk).exists())
+        self.assertFalse(ShareLink.objects.exists())
+
+    @mock.patch("documents.views.build_share_link_bundle.apply_async")
+    def test_root_permissions_allow_sharing_a_private_version(self, build_mock):
+        self.version.owner = UserFactory()
+        self.version.save(update_fields=["owner"])
+        grant_object(self.user, self.root, "view_document", "change_document")
+        note = Note.objects.create(document=self.version, note="Version note")
+        response = self.client.get(f"/api/documents/{self.version.pk}/notes/")
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data[0]["id"], note.pk)
+        response = self.client.post(
+            "/api/share_links/",
+            {"document": self.version.pk, "file_version": "original"},
+        )
+        self.assertEqual(response.status_code, 201)
+        self.assertEqual(ShareLink.objects.get().document_id, self.version.pk)
+        response = self.client.get(f"/api/documents/{self.version.pk}/share_links/")
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(len(response.data), 1)
+        response = self.client.post(
+            "/api/share_link_bundles/",
+            {"document_ids": [self.version.pk], "file_version": "original"},
+            format="json",
+        )
+        self.assertEqual(response.status_code, 201)
+        build_mock.assert_called_once()
+
+    def test_root_view_permission_does_not_allow_note_changes(self):
+        grant_object(self.user, self.root, "view_document")
+        note = Note.objects.create(document=self.version, note="Version note")
+        response = self.client.get(f"/api/documents/{self.version.pk}/notes/")
+        self.assertEqual(response.status_code, 200)
+        response = self.client.post(
+            f"/api/documents/{self.version.pk}/notes/",
+            {"note": "New note"},
+        )
+        self.assertEqual(response.status_code, 403)
+        response = self.client.delete(
+            f"/api/documents/{self.version.pk}/notes/?id={note.pk}",
+        )
+        self.assertEqual(response.status_code, 403)
+        self.assertTrue(Note.objects.filter(pk=note.pk).exists())
+
+    @override_settings(AUDIT_LOG_ENABLED=True)
+    def test_history_uses_root_ownership(self):
+        self.root.owner = self.user
+        self.root.save(update_fields=["owner"])
+        self.version.owner = UserFactory()
+        self.version.save(update_fields=["owner"])
+        response = self.client.get(f"/api/documents/{self.version.pk}/history/")
+        self.assertEqual(response.status_code, 200)
+
+    def test_selection_data_rejects_stale_version_ownership(self):
+        for owner in (None, self.user):
+            self.version.owner = owner
+            self.version.save(update_fields=["owner"])
+            with self.subTest(owner=owner):
+                response = self.client.post(
+                    "/api/documents/selection_data/",
+                    {"documents": [self.version.pk]},
+                    format="json",
+                )
+                self.assertEqual(response.status_code, 403)
+
+    def test_selection_data_allows_private_version_of_permitted_root(self):
+        self.version.owner = UserFactory()
+        self.version.save(update_fields=["owner"])
+        grant_object(self.user, self.root, "view_document")
+        other = DocumentFactory(owner=self.user)
+        response = self.client.post(
+            "/api/documents/selection_data/",
+            {"documents": [self.version.pk, other.pk]},
+            format="json",
+        )
+        self.assertEqual(response.status_code, 200)

src/documents/tests/test_api_search.py

@@ -1196,6 +1196,59 @@ class TestDocumentSearchApi(DirectoriesMixin, APITestCase):
         self.assertIn(d3.id, result_ids)
         self.assertNotIn(d4.id, result_ids)
 
+    def test_search_more_like_version_uses_its_root(self) -> None:
+        """
+        GIVEN:
+            - A document similar in content to a root document, and one that is not
+            - A version of the root document, which is never indexed
+        WHEN:
+            - API request for more like the version
+        THEN:
+            - The documents similar to the root are returned, not the version
+        """
+        indexed = {}
+        for name, title, content, day in (
+            ("root", "bank statement 1", "things i paid for in august", (2019, 3, 4)),
+            (
+                "similar",
+                "bank statement 3",
+                "things i paid for in september",
+                (2020, 7, 9),
+            ),
+            (
+                "other",
+                "Quarterly Report",
+                "quarterly revenue profit margin",
+                (2021, 11, 30),
+            ),
+        ):
+            with time_machine.travel(
+                timezone.make_aware(datetime.datetime(*day)),
+                tick=False,
+            ):
+                indexed[name] = DocumentFactory(
+                    title=title,
+                    content=content,
+                    created=datetime.date(*day),
+                    added=timezone.make_aware(datetime.datetime(*day)),
+                )
+        version = DocumentFactory(
+            root_document=indexed["root"],
+            version_index=1,
+            content="things i paid for in august",
+        )
+        backend = get_backend()
+        for document in indexed.values():
+            backend.add_or_update(document)
+
+        response = self.client.get(f"/api/documents/?more_like_id={version.id}")
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        result_ids = [r["id"] for r in response.data["results"]]
+        self.assertIn(indexed["similar"].id, result_ids)
+        self.assertNotIn(indexed["other"].id, result_ids)
+        self.assertNotIn(version.id, result_ids)
+
     def test_more_like_requires_id_of_existing_document(self) -> None:
         """
         GIVEN:

src/documents/tests/test_api_trash.py

@@ -6,6 +6,7 @@ from rest_framework.test import APITestCase
 
 from documents.models import Document
 from paperless_testing.dirs import DirectoriesMixin
+from paperless_testing.factories import DocumentFactory
 from paperless_testing.factories import UserFactory
 from paperless_testing.permissions import grant_all_global
 
@@ -279,3 +280,53 @@ class TestTrashAPI(DirectoriesMixin, APITestCase):
             Document.objects.filter(root_document=root).values_list("id", flat=True),
             [version.pk for version in versions],
         )
+
+    def test_api_trash_version_follows_root_owner(self) -> None:
+        """
+        GIVEN:
+            - A deleted version of user2's document, owned by nobody
+            - A deleted version of the user's document, owned by user2
+        WHEN:
+            - The user lists the trash and tries to restore or empty the versions
+        THEN:
+            - Only the version of the user's own document is listed
+            - The other version can't be restored or emptied
+            - The version of the user's own document can be restored
+        """
+        user2 = UserFactory(username="user2")
+        other_version = DocumentFactory(
+            root_document=DocumentFactory(owner=user2),
+            version_index=1,
+        )
+        other_version.delete()
+        own_version = DocumentFactory(
+            owner=user2,
+            root_document=DocumentFactory(owner=self.user),
+            version_index=1,
+        )
+        own_version.delete()
+
+        resp = self.client.get("/api/trash/")
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertEqual(
+            [doc["id"] for doc in resp.data["results"]],
+            [own_version.pk],
+        )
+
+        for action in ("restore", "empty"):
+            with self.subTest(action=action):
+                resp = self.client.post(
+                    "/api/trash/",
+                    {"action": action, "documents": [other_version.pk]},
+                )
+                self.assertEqual(resp.status_code, status.HTTP_403_FORBIDDEN)
+                self.assertTrue(
+                    Document.deleted_objects.filter(pk=other_version.pk).exists(),
+                )
+
+        resp = self.client.post(
+            "/api/trash/",
+            {"action": "restore", "documents": [own_version.pk]},
+        )
+        self.assertEqual(resp.status_code, status.HTTP_200_OK)
+        self.assertTrue(Document.objects.filter(pk=own_version.pk).exists())

src/documents/tests/test_bulk_edit.py

@@ -4,6 +4,7 @@ from pathlib import Path
 from unittest import mock
 
 import pikepdf
+import pytest
 from django.contrib.auth.models import Group
 from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
@@ -12,6 +13,7 @@ from django.test import TestCase
 from django.test.utils import CaptureQueriesContext
 from guardian.shortcuts import get_groups_with_perms
 from guardian.shortcuts import get_users_with_perms
+from pytest_mock import MockerFixture
 
 from documents import bulk_edit
 from documents.models import Correspondent
@@ -23,6 +25,7 @@ from documents.models import StoragePath
 from documents.models import Tag
 from documents.permissions import set_permissions_for_objects
 from paperless_testing.dirs import DirectoriesMixin
+from paperless_testing.factories import DocumentFactory
 from paperless_testing.permissions import grant_object
 
 
@@ -1970,18 +1973,22 @@ class TestPDFActions(DirectoriesMixin, TestCase):
         self.assertIn("Error removing password from document", cm.output[0])
 
 
-class TestBulkEditReprocess(DirectoriesMixin, TestCase):
-    def setUp(self) -> None:
-        super().setUp()
-
-        self.doc = Document.objects.create(
-            title="test",
-            checksum="A",
-            mime_type="application/pdf",
+@pytest.mark.django_db
+class TestBulkEditReprocess:
+    @pytest.fixture
+    def mock_task(self, mocker: MockerFixture) -> mock.MagicMock:
+        return mocker.patch(
+            "documents.bulk_edit.update_document_content_maybe_archive_file",
         )
 
-    @mock.patch("documents.bulk_edit.update_document_content_maybe_archive_file")
-    def test_reprocess_defaults_to_local(self, mock_task: mock.Mock) -> None:
+    @staticmethod
+    def _queued_ids(mock_task: mock.MagicMock) -> list[int]:
+        return [
+            call.kwargs["kwargs"]["document_id"]
+            for call in mock_task.apply_async.call_args_list
+        ]
+
+    def test_reprocess_defaults_to_local(self, mock_task: mock.MagicMock) -> None:
         """
         GIVEN:
             - A reprocess request that says nothing about remote OCR
@@ -1990,18 +1997,17 @@ class TestBulkEditReprocess(DirectoriesMixin, TestCase):
         THEN:
             - The task is queued without asking for the remote engine
         """
-        result = bulk_edit.reprocess([self.doc.id])
+        doc = DocumentFactory()
+
+        assert bulk_edit.reprocess([doc.id]) == "OK"
 
-        self.assertEqual(result, "OK")
         mock_task.apply_async.assert_called_once()
-        _, kwargs = mock_task.apply_async.call_args
-        self.assertEqual(
-            kwargs["kwargs"],
-            {"document_id": self.doc.id, "remote_ocr": False},
-        )
+        assert mock_task.apply_async.call_args.kwargs["kwargs"] == {
+            "document_id": doc.id,
+            "remote_ocr": False,
+        }
 
-    @mock.patch("documents.bulk_edit.update_document_content_maybe_archive_file")
-    def test_reprocess_passes_remote_ocr(self, mock_task: mock.Mock) -> None:
+    def test_reprocess_passes_remote_ocr(self, mock_task: mock.MagicMock) -> None:
         """
         GIVEN:
             - A reprocess request that explicitly asks for remote OCR
@@ -2010,14 +2016,72 @@ class TestBulkEditReprocess(DirectoriesMixin, TestCase):
         THEN:
             - The request is forwarded to the task for every document
         """
-        other = Document.objects.create(
-            title="test2",
-            checksum="B",
-            mime_type="application/pdf",
+        docs = DocumentFactory.create_batch(2)
+
+        bulk_edit.reprocess([doc.id for doc in docs], remote_ocr=True)
+
+        assert mock_task.apply_async.call_count == 2
+        for call in mock_task.apply_async.call_args_list:
+            assert call.kwargs["kwargs"]["remote_ocr"]
+
+    def test_reprocess_root_uses_latest_version(
+        self,
+        mock_task: mock.MagicMock,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with two versions
+        WHEN:
+            - reprocess is called with the root document
+        THEN:
+            - The latest version is reprocessed, not the root's original file
+        """
+        root = DocumentFactory()
+        DocumentFactory(root_document=root, version_index=1)
+        latest = DocumentFactory(root_document=root, version_index=2)
+
+        bulk_edit.reprocess([root.id])
+
+        assert self._queued_ids(mock_task) == [latest.id]
+
+    def test_reprocess_explicit_version(self, mock_task: mock.MagicMock) -> None:
+        """
+        GIVEN:
+            - A root document with two versions
+        WHEN:
+            - reprocess is called with the older version
+        THEN:
+            - That version is reprocessed
+        """
+        root = DocumentFactory()
+        older = DocumentFactory(root_document=root, version_index=1)
+        DocumentFactory(root_document=root, version_index=2)
+
+        bulk_edit.reprocess([older.id])
+
+        assert self._queued_ids(mock_task) == [older.id]
+
+    def test_reprocess_root_and_latest_version_dispatches_once(
+        self,
+        mock_task: mock.MagicMock,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with two versions, the latest created on a
+              different date than the root
+        WHEN:
+            - reprocess is called with both the root and its latest version
+        THEN:
+            - The latest version is reprocessed only once
+        """
+        root = DocumentFactory(created=date(2024, 1, 1))
+        DocumentFactory(root_document=root, version_index=1)
+        latest = DocumentFactory(
+            root_document=root,
+            version_index=2,
+            created=date(2025, 1, 1),
         )
 
-        bulk_edit.reprocess([self.doc.id, other.id], remote_ocr=True)
+        bulk_edit.reprocess([root.id, latest.id])
 
-        self.assertEqual(mock_task.apply_async.call_count, 2)
-        for call in mock_task.apply_async.call_args_list:
-            self.assertTrue(call.kwargs["kwargs"]["remote_ocr"])
+        assert self._queued_ids(mock_task) == [latest.id]

src/documents/tests/test_management.py

@@ -22,6 +22,7 @@ from documents.models import Document
 from documents.tasks import update_document_content_maybe_archive_file
 from paperless_testing.assertions import FileSystemAssertsMixin
 from paperless_testing.dirs import DirectoriesMixin
+from paperless_testing.factories import DocumentFactory
 
 sample_file: Path = Path(__file__).parent / "samples" / "simple.pdf"
 
@@ -116,6 +117,27 @@ class TestMakeIndex:
         call_command("document_index", "reindex", skip_checks=True)
         mock_get_backend.return_value.rebuild.assert_called_once()
 
+    def test_reindex_skips_versions(self, mocker: MockerFixture) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - The reindex command runs
+        THEN:
+            - Only the root document is handed to the rebuild, since a version
+              is indexed as its root
+        """
+        root = DocumentFactory()
+        DocumentFactory(root_document=root, version_index=1)
+        mock_get_backend = mocker.patch(
+            "documents.management.commands.document_index.get_backend",
+        )
+
+        call_command("document_index", "reindex", skip_checks=True)
+
+        documents = mock_get_backend.return_value.rebuild.call_args.args[0]
+        assert list(documents.values_list("pk", flat=True)) == [root.pk]
+
     def test_optimize(self) -> None:
         """Optimize command must execute without error (Tantivy handles optimization automatically)."""
         call_command("document_index", "optimize", skip_checks=True)

src/documents/tests/test_permission_filtering_security.py

@@ -18,6 +18,7 @@ from documents.models import Correspondent
 from documents.models import DocumentType
 from documents.models import StoragePath
 from documents.models import Tag
+from documents.permissions import has_perms_owner_aware
 from documents.permissions import permitted_document_ids
 from documents.permissions import permitted_object_ids
 from documents.permissions import restrict_queryset_to_visible
@@ -32,6 +33,8 @@ from paperless_testing.permissions import grant_global
 from paperless_testing.permissions import grant_object
 
 if TYPE_CHECKING:
+    from django.contrib.auth.models import User
+
     from paperless_testing.dirs import PaperlessDirs
 
 
@@ -178,6 +181,382 @@ class TestPermittedDocumentIdsIncludeDeleted:
         )
 
 
+@pytest.mark.django_db
+class TestPermittedDocumentIdsVersions:
+    """
+    A version is authorized by its root document: the version's own owner and
+    grants never matter.
+    """
+
+    @pytest.mark.parametrize(
+        ("root_owner", "version_owner", "expected_visible"),
+        [
+            pytest.param(
+                "other",
+                "nobody",
+                False,
+                id="unowned-version-of-private-root",
+            ),
+            pytest.param("other", "user", False, id="own-version-of-private-root"),
+            pytest.param("user", "other", True, id="foreign-version-of-own-root"),
+            pytest.param("user", "nobody", True, id="unowned-version-of-own-root"),
+            pytest.param("nobody", "other", True, id="private-version-of-unowned-root"),
+        ],
+    )
+    def test_version_follows_root_owner(
+        self,
+        root_owner: str,
+        version_owner: str,
+        *,
+        expected_visible: bool,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document and a version with differing owners
+        WHEN:
+            - The permitted document ids are resolved for the user
+        THEN:
+            - The version is visible exactly when its root is
+        """
+        user = UserFactory()
+        owners = {"user": user, "other": UserFactory(), "nobody": None}
+        root = DocumentFactory(owner=owners[root_owner])
+        version = DocumentFactory(root_document=root, owner=owners[version_owner])
+
+        visible = set(permitted_document_ids(user))
+
+        assert (version.pk in visible) is expected_visible
+        assert (root.pk in visible) is expected_visible
+
+    @staticmethod
+    def grantee(user: User, kind: str) -> User | Group:
+        """The user itself, or a new group the user belongs to."""
+        if kind == "user":
+            return user
+        group = Group.objects.create(name="shared")
+        user.groups.add(group)
+        return group
+
+    @pytest.mark.parametrize(
+        "grantee_kind",
+        [pytest.param("user", id="user"), pytest.param("group", id="group")],
+    )
+    def test_grant_on_root_applies_to_version(self, grantee_kind: str) -> None:
+        """
+        GIVEN:
+            - A private root document shared with a user or one of their groups
+            - A version of it owned by someone else
+        WHEN:
+            - The permitted document ids are resolved for the user
+        THEN:
+            - Both the root and the version are visible
+            - A user without the grant sees neither
+        """
+        user = UserFactory()
+        stranger = UserFactory()
+        root = DocumentFactory(owner=UserFactory())
+        version = DocumentFactory(root_document=root, owner=UserFactory())
+        grant_object(self.grantee(user, grantee_kind), root, "view_document")
+
+        assert_visible_document_ids(
+            permitted_document_ids(user),
+            expected_visible=[root.pk, version.pk],
+            expected_hidden=[],
+        )
+        assert_visible_document_ids(
+            permitted_document_ids(stranger),
+            expected_visible=[],
+            expected_hidden=[root.pk, version.pk],
+        )
+
+    @pytest.mark.parametrize(
+        "grantee_kind",
+        [pytest.param("user", id="user"), pytest.param("group", id="group")],
+    )
+    def test_grant_on_version_is_ignored(self, grantee_kind: str) -> None:
+        """
+        GIVEN:
+            - A private root document
+            - A version with an explicit grant for the user or one of their groups
+        WHEN:
+            - The permitted document ids are resolved for the user
+        THEN:
+            - Neither the root nor the version is visible
+        """
+        user = UserFactory()
+        root = DocumentFactory(owner=UserFactory())
+        version = DocumentFactory(root_document=root, owner=UserFactory())
+        grant_object(self.grantee(user, grantee_kind), version, "view_document")
+
+        assert_visible_document_ids(
+            permitted_document_ids(user),
+            expected_visible=[],
+            expected_hidden=[root.pk, version.pk],
+        )
+
+    def test_grant_on_one_root_does_not_reach_another_roots_version(self) -> None:
+        """
+        GIVEN:
+            - Two private roots, each with a version
+            - The user may view only the first root
+        WHEN:
+            - The permitted document ids are resolved for the user
+        THEN:
+            - Only the first root and its version are visible
+        """
+        user = UserFactory()
+        first = DocumentFactory(owner=UserFactory())
+        first_version = DocumentFactory(root_document=first, owner=UserFactory())
+        second = DocumentFactory(owner=UserFactory())
+        second_version = DocumentFactory(root_document=second, owner=user)
+        grant_object(user, first, "view_document")
+
+        assert_visible_document_ids(
+            permitted_document_ids(user),
+            expected_visible=[first.pk, first_version.pk],
+            expected_hidden=[second.pk, second_version.pk],
+        )
+
+    def test_user_in_several_groups(self) -> None:
+        """
+        GIVEN:
+            - A user in two groups
+            - Two private roots shared with one group each, and a third shared with nobody
+            - A version of each root
+        WHEN:
+            - The permitted document ids are resolved for the user
+        THEN:
+            - The two shared roots and their versions are visible
+            - The third root and its version are not
+        """
+        user = UserFactory()
+        groups = [Group.objects.create(name=f"group{i}") for i in range(2)]
+        user.groups.add(*groups)
+        shared = [DocumentFactory(owner=UserFactory()) for _ in groups]
+        for root, group in zip(shared, groups, strict=True):
+            grant_object(group, root, "view_document")
+        unshared = DocumentFactory(owner=UserFactory())
+        shared_versions = [
+            DocumentFactory(root_document=root, owner=UserFactory()) for root in shared
+        ]
+        unshared_version = DocumentFactory(root_document=unshared, owner=None)
+
+        assert_visible_document_ids(
+            permitted_document_ids(user),
+            expected_visible=[
+                *(root.pk for root in shared),
+                *(version.pk for version in shared_versions),
+            ],
+            expected_hidden=[unshared.pk, unshared_version.pk],
+        )
+
+    def test_permission_is_resolved_through_the_root(self) -> None:
+        """
+        GIVEN:
+            - A private root document where the user may view and change
+        WHEN:
+            - The permitted ids are resolved for view, change and delete
+        THEN:
+            - The version is visible for view and change only
+        """
+        user = UserFactory()
+        root = DocumentFactory(owner=UserFactory())
+        version = DocumentFactory(root_document=root, owner=UserFactory())
+        grant_object(user, root, "view_document", "change_document")
+
+        assert version.pk in set(permitted_document_ids(user))
+        assert version.pk in set(permitted_document_ids(user, perm="change_document"))
+        assert version.pk in set(
+            permitted_document_ids(user, perm="documents.change_document"),
+        )
+        assert version.pk not in set(
+            permitted_document_ids(user, perm="delete_document"),
+        )
+
+    def test_anonymous_sees_versions_of_unowned_roots_only(self) -> None:
+        """
+        GIVEN:
+            - A version owned by nobody under a private root
+            - A version owned by someone under an unowned root
+        WHEN:
+            - The permitted document ids are resolved for an anonymous user
+        THEN:
+            - Only the version of the unowned root is visible
+        """
+        private_root = DocumentFactory(owner=UserFactory())
+        private_version = DocumentFactory(root_document=private_root, owner=None)
+        open_root = DocumentFactory(owner=None)
+        open_version = DocumentFactory(root_document=open_root, owner=UserFactory())
+
+        assert_visible_document_ids(
+            permitted_document_ids(AnonymousUser()),
+            expected_visible=[open_root.pk, open_version.pk],
+            expected_hidden=[private_root.pk, private_version.pk],
+        )
+
+    def test_deleted_versions_follow_their_deleted_root(self) -> None:
+        """
+        GIVEN:
+            - A soft-deleted root document and its version, which deleting the
+              root soft-deletes too; the version is owned by someone else
+        WHEN:
+            - The permitted document ids are resolved with and without deleted
+              documents
+        THEN:
+            - Nothing is visible by default
+            - With deleted documents included, the version is visible to the
+              root's owner and not to the version's own owner
+        """
+        owner = UserFactory()
+        version_owner = UserFactory()
+        root = DocumentFactory(owner=owner)
+        version = DocumentFactory(root_document=root, owner=version_owner)
+        root.delete()
+
+        assert not {root.pk, version.pk} & set(permitted_document_ids(owner))
+        assert_visible_document_ids(
+            permitted_document_ids(owner, include_deleted=True),
+            expected_visible=[root.pk, version.pk],
+            expected_hidden=[],
+        )
+        assert_visible_document_ids(
+            permitted_document_ids(version_owner, include_deleted=True),
+            expected_visible=[],
+            expected_hidden=[root.pk, version.pk],
+        )
+
+    @pytest.mark.parametrize(
+        "is_superuser",
+        [
+            pytest.param(False, id="regular-user"),
+            pytest.param(True, id="superuser"),
+        ],
+    )
+    def test_inactive_user_sees_no_versions(self, *, is_superuser: bool) -> None:
+        """
+        GIVEN:
+            - An inactive user, possibly a superuser, who owns a root and its version
+        WHEN:
+            - The permitted document ids are resolved for them
+        THEN:
+            - Nothing is visible
+        """
+        user = UserFactory(is_active=False, is_superuser=is_superuser)
+        root = DocumentFactory(owner=user)
+        version = DocumentFactory(root_document=root, owner=user)
+
+        assert_visible_document_ids(
+            permitted_document_ids(user),
+            expected_visible=[],
+            expected_hidden=[root.pk, version.pk],
+        )
+
+    def test_superuser_sees_all_versions(self) -> None:
+        """
+        GIVEN:
+            - A private root owned by someone else, with a version
+        WHEN:
+            - The permitted document ids are resolved for a superuser
+        THEN:
+            - Both the root and the version are visible
+        """
+        superuser = UserFactory(superuser=True)
+        root = DocumentFactory(owner=UserFactory())
+        version = DocumentFactory(root_document=root, owner=UserFactory())
+
+        assert_visible_document_ids(
+            permitted_document_ids(superuser),
+            expected_visible=[root.pk, version.pk],
+            expected_hidden=[],
+        )
+
+
+@pytest.mark.django_db
+class TestHasPermsOwnerAwareVersions:
+    """
+    The single-object check agrees with permitted_document_ids: a version is
+    authorized by its root document.
+    """
+
+    @pytest.mark.parametrize(
+        ("root_owner", "version_owner", "expected"),
+        [
+            pytest.param(
+                "other",
+                "nobody",
+                False,
+                id="unowned-version-of-private-root",
+            ),
+            pytest.param("other", "user", False, id="own-version-of-private-root"),
+            pytest.param("user", "other", True, id="foreign-version-of-own-root"),
+            pytest.param("nobody", "other", True, id="private-version-of-unowned-root"),
+        ],
+    )
+    def test_version_follows_root_owner(
+        self,
+        root_owner: str,
+        version_owner: str,
+        *,
+        expected: bool,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document and a version with differing owners
+        WHEN:
+            - The single-object check runs for the version
+        THEN:
+            - The version is allowed exactly when its root is
+        """
+        user = UserFactory()
+        owners = {"user": user, "other": UserFactory(), "nobody": None}
+        root = DocumentFactory(owner=owners[root_owner])
+        version = DocumentFactory(root_document=root, owner=owners[version_owner])
+
+        assert has_perms_owner_aware(user, "view_document", version) is expected
+        assert has_perms_owner_aware(user, "view_document", root) is expected
+
+    def test_grant_on_root_applies_and_grant_on_version_does_not(self) -> None:
+        """
+        GIVEN:
+            - A private root with a version, and a second private root with a version
+            - The user may change only the first root, and was granted the second
+              root's version directly
+        WHEN:
+            - The single-object check runs for each version
+        THEN:
+            - Only the first root's version is allowed
+        """
+        user = UserFactory()
+        shared_root = DocumentFactory(owner=UserFactory())
+        shared_version = DocumentFactory(root_document=shared_root, owner=UserFactory())
+        private_root = DocumentFactory(owner=UserFactory())
+        private_version = DocumentFactory(
+            root_document=private_root,
+            owner=UserFactory(),
+        )
+        grant_object(user, shared_root, "change_document")
+        grant_object(user, private_version, "change_document")
+
+        assert has_perms_owner_aware(user, "change_document", shared_version)
+        assert not has_perms_owner_aware(user, "change_document", private_version)
+
+    def test_other_models_use_their_own_owner(self) -> None:
+        """
+        GIVEN:
+            - A tag owned by someone else, and one owned by the user
+        WHEN:
+            - The single-object check runs for each
+        THEN:
+            - Only the user's own tag is allowed without a grant
+        """
+        user = UserFactory()
+        mine = TagFactory(owner=user)
+        theirs = TagFactory(owner=UserFactory())
+
+        assert has_perms_owner_aware(user, "view_tag", mine)
+        assert not has_perms_owner_aware(user, "view_tag", theirs)
+
+
 @pytest.mark.django_db
 class TestAiChatAllDocumentsPermissionBoundary:
     """

src/documents/tests/test_share_link_bundles.py

@@ -90,10 +90,13 @@ class ShareLinkBundleAPITests(DirectoriesMixin, APITestCase):
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
         self.assertIn("document_ids", response.data)
 
-    @mock.patch("documents.views.permitted_document_ids", return_value=set())
-    def test_create_bundle_rejects_insufficient_permissions(self, perms_mock) -> None:
+    def test_create_bundle_rejects_insufficient_permissions(self) -> None:
+        requester = UserFactory(username="bundle_creator")
+        grant_global(requester, "add_sharelinkbundle", "view_document")
+        self.client.force_authenticate(requester)
+        document = DocumentFactory(owner=UserFactory(username="document_owner"))
         payload = {
-            "document_ids": [self.document.pk],
+            "document_ids": [self.document.pk, document.pk],
             "file_version": ShareLink.FileVersion.ARCHIVE,
             "expiration_days": 7,
         }
@@ -101,8 +104,8 @@ class ShareLinkBundleAPITests(DirectoriesMixin, APITestCase):
         response = self.client.post(self.ENDPOINT, payload, format="json")
 
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
-        self.assertIn("document_ids", response.data)
-        perms_mock.assert_called()
+        self.assertIn(str(document.pk), str(response.data["document_ids"]))
+        self.assertFalse(ShareLinkBundle.objects.exists())
 
     @mock.patch("documents.views.build_share_link_bundle.apply_async")
     def test_rebuild_bundle_resets_state(self, delay_mock) -> None:

src/documents/tests/test_tasks.py

@@ -20,6 +20,7 @@ from documents.sanity_checker import SanityCheckMessages
 from documents.tests.helpers import dummy_preprocess
 from paperless_testing.assertions import FileSystemAssertsMixin
 from paperless_testing.dirs import DirectoriesMixin
+from paperless_testing.factories import DocumentFactory
 
 
 @pytest.mark.django_db
@@ -287,6 +288,80 @@ class TestUpdateContent(DirectoriesMixin, TestCase):
         tasks.update_document_content_maybe_archive_file(doc.pk)
         self.assertNotEqual(Document.objects.get(pk=doc.pk).content, "test")
 
+    def _create_root_with_version(self) -> tuple[Document, Document]:
+        sample1 = self.dirs.scratch_dir / "sample.pdf"
+        shutil.copy(
+            Path(__file__).parent
+            / "samples"
+            / "documents"
+            / "originals"
+            / "0000001.pdf",
+            sample1,
+        )
+        root = DocumentFactory(content="root content", mime_type="application/pdf")
+        version = DocumentFactory(
+            content="my document",
+            filename=sample1,
+            mime_type="application/pdf",
+            root_document=root,
+            version_index=1,
+        )
+        return root, version
+
+    @mock.patch("documents.tasks.clear_document_caches")
+    @mock.patch("documents.search.get_backend")
+    def test_update_content_version_clears_caches_for_root(
+        self,
+        mock_get_backend: mock.Mock,
+        mock_clear_caches: mock.Mock,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - Update content task is called for the version
+        THEN:
+            - The version's content is updated, not the root's
+            - The document is indexed
+            - Caches are cleared for both
+        """
+        root, version = self._create_root_with_version()
+
+        tasks.update_document_content_maybe_archive_file(version.pk)
+
+        self.assertNotEqual(
+            Document.objects.get(pk=version.pk).content,
+            "my document",
+        )
+        self.assertEqual(Document.objects.get(pk=root.pk).content, "root content")
+        mock_get_backend.return_value.add_or_update.assert_called_once()
+        mock_clear_caches.assert_has_calls(
+            [mock.call(version.pk), mock.call(root.pk)],
+        )
+
+    @override_settings(AI_ENABLED=True, LLM_EMBEDDING_BACKEND="huggingface")
+    @mock.patch("documents.tasks.llm_index_add_or_update_document")
+    @mock.patch("documents.search.get_backend")
+    def test_update_content_version_updates_llm_index(
+        self,
+        mock_get_backend: mock.Mock,
+        mock_llm_index: mock.Mock,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+            - The LLM index is enabled
+        WHEN:
+            - Update content task is called for the version
+        THEN:
+            - The LLM index is updated
+        """
+        _, version = self._create_root_with_version()
+
+        tasks.update_document_content_maybe_archive_file(version.pk)
+
+        mock_llm_index.assert_called_once()
+
 
 class TestUpdateContentRemoteOCR(DirectoriesMixin, TestCase):
     """

src/documents/versioning.py

@@ -17,9 +17,26 @@ from django.db.models.functions import RowNumber
 from documents.models import Document
 
 if TYPE_CHECKING:
+    from collections.abc import Iterable
+
     from rest_framework.request import Request
 
 
+def root_document_ids(ids: Iterable[int]) -> QuerySet[int]:
+    """
+    The ids of the root documents of the given documents: a root stands for
+    itself and a version for its root. Only the indexes' bookkeeping needs
+    this, since they hold root documents only.
+    """
+    return (
+        Document.objects.filter(pk__in=ids)
+        .annotate(root_id=Coalesce("root_document_id", "id"))
+        .order_by()
+        .values_list("root_id", flat=True)
+        .distinct()
+    )
+
+
 def versions_newest_first(documents: QuerySet[Document]) -> QuerySet[Document]:
     """
     Sorts versions so the newest one comes first using version_index and not on id,

src/documents/views.py

@@ -329,9 +329,10 @@ def _get_tantivy_query_and_mode(params):
 def _get_more_like_id(query_params: dict[str, Any], user: User | None) -> int:
     try:
         more_like_doc_id = int(query_params["more_like_id"])
-        more_like_doc = Document.objects.select_related("owner").get(
-            pk=more_like_doc_id,
-        )
+        more_like_doc = Document.objects.select_related(
+            "owner",
+            "root_document__owner",
+        ).get(pk=more_like_doc_id)
     except (TypeError, ValueError, Document.DoesNotExist):
         raise PermissionDenied(_("Invalid more_like_id"))
 
@@ -342,7 +343,8 @@ def _get_more_like_id(query_params: dict[str, Any], user: User | None) -> int:
     ):
         raise PermissionDenied(_("Insufficient permissions."))
 
-    return more_like_doc_id
+    # Only root documents are indexed, a version stands for its root
+    return more_like_doc.root_document_id or more_like_doc.pk
 
 
 class SearchParams(NamedTuple):
@@ -1550,7 +1552,10 @@ class DocumentViewSet(
     )
     def suggestions(self, request, pk=None):
         doc = get_object_or_404(
-            Document.objects.select_related("owner").prefetch_related("versions"),
+            Document.objects.select_related(
+                "owner",
+                "root_document__owner",
+            ).prefetch_related("versions"),
             pk=pk,
         )
         if request.user is not None and not has_perms_owner_aware(
@@ -1610,7 +1615,10 @@ class DocumentViewSet(
     @method_decorator(cache_control(no_cache=True))
     def ai_suggestions(self, request, pk=None):
         doc = get_object_or_404(
-            Document.objects.select_related("owner").prefetch_related("versions"),
+            Document.objects.select_related(
+                "owner",
+                "root_document__owner",
+            ).prefetch_related("versions"),
             pk=pk,
         )
         if request.user is not None and not has_perms_owner_aware(
@@ -1856,9 +1864,14 @@ class DocumentViewSet(
         currentUser = request.user
         try:
             doc = (
-                Document.objects.select_related("owner")
+                Document.objects.select_related("owner", "root_document__owner")
                 .prefetch_related("notes")
-                .only("pk", "owner__id")
+                .only(
+                    "pk",
+                    "owner__id",
+                    "root_document__id",
+                    "root_document__owner__id",
+                )
                 .get(pk=pk)
             )
             if currentUser is not None and not has_perms_owner_aware(
@@ -1973,7 +1986,9 @@ class DocumentViewSet(
     def share_links(self, request, pk=None):
         currentUser = request.user
         try:
-            doc = Document.objects.select_related("owner").get(pk=pk)
+            doc = Document.objects.select_related("owner", "root_document__owner").get(
+                pk=pk,
+            )
             if currentUser is not None and not has_perms_owner_aware(
                 currentUser,
                 "change_document",
@@ -2008,10 +2023,11 @@ class DocumentViewSet(
         if not settings.AUDIT_LOG_ENABLED:
             return HttpResponseBadRequest("Audit log is disabled")
         try:
-            doc = Document.objects.get(pk=pk)
+            doc = Document.objects.select_related("root_document__owner").get(pk=pk)
+            root_doc = get_root_document(doc)
             if not request.user.has_perm("auditlog.view_logentry") or (
-                doc.owner is not None
-                and doc.owner != request.user
+                root_doc.owner is not None
+                and root_doc.owner != request.user
                 and not request.user.is_superuser
             ):
                 return HttpResponseForbidden(
@@ -2102,9 +2118,7 @@ class DocumentViewSet(
         documents = Document.objects.filter(pk__in=document_ids)
         if (
             request.user is not None
-            and documents.exclude(
-                pk__in=permitted_document_ids(request.user),
-            ).exists()
+            and documents.exclude(id__in=permitted_document_ids(request.user)).exists()
         ):
             return HttpResponseForbidden("Insufficient permissions")
 
@@ -2430,11 +2444,17 @@ class ChatStreamingView(GenericAPIView[Any]):
 
         if doc_id:
             try:
-                document = Document.objects.get(id=doc_id)
+                document = Document.objects.select_related(
+                    "root_document__owner",
+                ).get(id=doc_id)
             except Document.DoesNotExist:
                 return HttpResponseBadRequest("Document not found")
 
-            if not has_perms_owner_aware(request.user, "view_document", document):
+            if not has_perms_owner_aware(
+                request.user,
+                "view_document",
+                document,
+            ):
                 return HttpResponseForbidden("Insufficient permissions")
 
             documents = Document.objects.filter(pk=document.pk)
@@ -2990,12 +3010,8 @@ class DocumentOperationPermissionMixin(PassUserMixin, DocumentSelectionMixin):
             user.has_perm(
                 "documents.change_document",
             )
-            and not Document.global_objects.filter(
-                pk__in=[doc.pk for doc in root_docs],
-            )
-            .exclude(
-                pk__in=permitted_document_ids(user, perm="change_document"),
-            )
+            and not Document.global_objects.filter(pk__in=documents)
+            .exclude(pk__in=permitted_document_ids(user, perm="change_document"))
             .exists()
         )
 
@@ -3605,10 +3621,11 @@ class SelectionDataView(DocumentSelectionMixin, GenericAPIView[Any]):
             user=request.user,
             validated_data=serializer.validated_data,
         )
-        permitted_documents = Document.objects.filter(
-            id__in=permitted_document_ids(request.user),
-        )
-        if permitted_documents.filter(pk__in=ids).count() != len(ids):
+        documents = Document.objects.filter(pk__in=ids)
+        if (
+            documents.count() != len(ids)
+            or documents.exclude(id__in=permitted_document_ids(request.user)).exists()
+        ):
             return HttpResponseForbidden("Insufficient permissions")
 
         correspondents = Correspondent.objects.annotate(
@@ -4104,21 +4121,16 @@ class BulkDownloadView(DocumentSelectionMixin, GenericAPIView[Any]):
             validated_data=serializer.validated_data,
         )
         documents = Document.objects.filter(pk__in=ids)
-        versioned_documents = []
         compression = serializer.validated_data.get("compression")
         content = serializer.validated_data.get("content")
         follow_filename_format = serializer.validated_data.get("follow_formatting")
 
-        permitted_ids = set(permitted_document_ids(request.user))
-        for document in documents:
-            root_doc = get_root_document(document)
-            if root_doc.pk not in permitted_ids:
-                return HttpResponseForbidden("Insufficient permissions")
-            versioned_documents.append(
-                get_latest_version_for_root(
-                    root_doc,
-                ),
-            )
+        if documents.exclude(id__in=permitted_document_ids(request.user)).exists():
+            return HttpResponseForbidden("Insufficient permissions")
+        versioned_documents = [
+            get_latest_version_for_root(get_root_document(document))
+            for document in documents
+        ]
 
         if content == "both":
             strategy_class = OriginalAndArchiveStrategy
@@ -4790,19 +4802,23 @@ class ShareLinkBundleViewSet(PassUserMixin, ModelViewSet[ShareLinkBundle]):
                 },
             )
 
-        documents = list(documents_qs)
-        permitted_ids = set(permitted_document_ids(request.user))
-        for document in documents:
-            if document.pk not in permitted_ids:
-                raise ValidationError(
-                    {
-                        "document_ids": _(
-                            "Insufficient permissions to share document %(id)s.",
-                        )
-                        % {"id": document.pk},
-                    },
-                )
+        denied_id = (
+            documents_qs.exclude(id__in=permitted_document_ids(request.user))
+            .order_by("pk")
+            .values_list("pk", flat=True)
+            .first()
+        )
+        if denied_id is not None:
+            raise ValidationError(
+                {
+                    "document_ids": _(
+                        "Insufficient permissions to share document %(id)s.",
+                    )
+                    % {"id": denied_id},
+                },
+            )
 
+        documents = list(documents_qs)
         document_map = {document.pk: document for document in documents}
         ordered_documents = [document_map[doc_id] for doc_id in document_ids]
 
@@ -5587,6 +5603,23 @@ class TrashView(ListModelMixin, PassUserMixin):
     class _TrashPermittedObjectsFilter(PermittedObjectsFilter):
         include_granted = False
 
+        def filter_queryset(self, request, queryset, view):
+            if request.user.is_superuser or not request.user.is_active:
+                return super().filter_queryset(request, queryset, view)
+
+            # A version belongs to whoever owns its root
+            def owned_or_unowned(prefix: str) -> Q:
+                return Q(**{f"{prefix}owner": request.user}) | Q(
+                    **{f"{prefix}owner__isnull": True},
+                )
+
+            return queryset.filter(
+                (Q(root_document__isnull=True) & owned_or_unowned(""))
+                | (
+                    Q(root_document__isnull=False) & owned_or_unowned("root_document__")
+                ),
+            )
+
     filter_backends = (_TrashPermittedObjectsFilter,)
     pagination_class = StandardPagination
 
@@ -5617,7 +5650,7 @@ class TrashView(ListModelMixin, PassUserMixin):
             else self.filter_queryset(self.get_queryset()).all()
         )
         if docs.exclude(
-            pk__in=permitted_document_ids(
+            id__in=permitted_document_ids(
                 request.user,
                 perm="delete_document",
                 include_deleted=True,

src/locale/en_US/LC_MESSAGES/django.po

@@ -2,7 +2,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: paperless-ngx\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2026-10-05 16:26+0000\n"
+"POT-Creation-Date: 2026-10-08 18:39+0000\n"
 "PO-Revision-Date: 2022-02-17 04:17\n"
 "Last-Translator: \n"
 "Language-Team: English\n"
@@ -1652,49 +1652,49 @@ msgstr ""
 msgid "workflow runs"
 msgstr ""
 
-#: documents/serialisers.py:515 documents/serialisers.py:872
-#: documents/serialisers.py:2902 documents/views.py:343 documents/views.py:2732
+#: documents/serialisers.py:516 documents/serialisers.py:873
+#: documents/serialisers.py:2903 documents/views.py:344 documents/views.py:2751
 #: paperless_mail/serialisers.py:156
 msgid "Insufficient permissions."
 msgstr ""
 
-#: documents/serialisers.py:708
+#: documents/serialisers.py:709
 msgid "Invalid color."
 msgstr ""
 
-#: documents/serialisers.py:2369
+#: documents/serialisers.py:2370
 #, python-format
 msgid "File type %(type)s not supported"
 msgstr ""
 
-#: documents/serialisers.py:2413
+#: documents/serialisers.py:2414
 #, python-format
 msgid "Custom field id must be an integer: %(id)s"
 msgstr ""
 
-#: documents/serialisers.py:2420
+#: documents/serialisers.py:2421
 #, python-format
 msgid "Custom field with id %(id)s does not exist"
 msgstr ""
 
-#: documents/serialisers.py:2437 documents/serialisers.py:2447
+#: documents/serialisers.py:2438 documents/serialisers.py:2448
 msgid ""
 "Custom fields must be a list of integers or an object mapping ids to values."
 msgstr ""
 
-#: documents/serialisers.py:2442
+#: documents/serialisers.py:2443
 msgid "Some custom fields don't exist or were specified twice."
 msgstr ""
 
-#: documents/serialisers.py:2589
+#: documents/serialisers.py:2590
 msgid "Invalid variable detected."
 msgstr ""
 
-#: documents/serialisers.py:2958
+#: documents/serialisers.py:2959
 msgid "Duplicate document identifiers are not allowed."
 msgstr ""
 
-#: documents/serialisers.py:2988 documents/views.py:4787
+#: documents/serialisers.py:2989 documents/views.py:4807
 #, python-format
 msgid "Documents not found: %(ids)s"
 msgstr ""
@@ -1941,61 +1941,44 @@ msgstr ""
 msgid "As a final step, please complete the following form:"
 msgstr ""
 
-#: documents/validators.py:24
-#, python-brace-format
-msgid "Unable to parse URI {value}, missing scheme"
-msgstr ""
-
-#: documents/validators.py:29
-#, python-brace-format
-msgid "Unable to parse URI {value}, missing net location or path"
-msgstr ""
-
 #: documents/validators.py:36
-msgid ""
-"URI scheme '{parts.scheme}' is not allowed. Allowed schemes: {', '."
-"join(allowed_schemes)}"
+msgid ", "
 msgstr ""
 
-#: documents/validators.py:45
-#, python-brace-format
-msgid "Unable to parse URI {value}"
-msgstr ""
-
-#: documents/views.py:336 documents/views.py:2729
+#: documents/views.py:337 documents/views.py:2748
 msgid "Invalid more_like_id"
 msgstr ""
 
-#: documents/views.py:1676
+#: documents/views.py:1683
 msgid "Invalid AI configuration."
 msgstr ""
 
-#: documents/views.py:1687
+#: documents/views.py:1694
 msgid "AI backend request timed out."
 msgstr ""
 
-#: documents/views.py:1699
+#: documents/views.py:1706
 msgid "AI backend rejected the request. Check logs for details."
 msgstr ""
 
-#: documents/views.py:2554 documents/views.py:2870
+#: documents/views.py:2573 documents/views.py:2889
 msgid "Specify only one of text, title_search, query, or more_like_id."
 msgstr ""
 
-#: documents/views.py:4800
+#: documents/views.py:4823
 #, python-format
 msgid "Insufficient permissions to share document %(id)s."
 msgstr ""
 
-#: documents/views.py:4846
+#: documents/views.py:4870
 msgid "Bundle is already being processed."
 msgstr ""
 
-#: documents/views.py:4910
+#: documents/views.py:4934
 msgid "The share link bundle is still being prepared. Please try again later."
 msgstr ""
 
-#: documents/views.py:4924
+#: documents/views.py:4948
 msgid "The share link bundle is unavailable."
 msgstr ""
 

src/paperless/tests/parsers/test_mail_parser_live.py

@@ -137,9 +137,20 @@ class TestNginxService:
     reason="No Gotenberg/Tika servers to test with",
 )
 class TestParserLive:
-    @staticmethod
-    def imagehash(file: Path, hash_size: int = 18) -> str:
-        return f"{average_hash(Image.open(file), hash_size)}"
+    # Rasterizer versions shift a few pixels, so compare perceptual hashes by
+    # Hamming distance (out of 18 * 18 = 324 bits) rather than for equality
+    MAX_HASH_DISTANCE = 8
+
+    @classmethod
+    def assert_thumbnails_similar(cls, generated: Path, expected: Path) -> None:
+        distance = average_hash(Image.open(generated), 18) - average_hash(
+            Image.open(expected),
+            18,
+        )
+        assert distance <= cls.MAX_HASH_DISTANCE, (
+            f"Thumbnail {generated} differs from {expected} by {distance} bits "
+            f"(max {cls.MAX_HASH_DISTANCE})"
+        )
 
     def test_get_thumbnail(
         self,
@@ -168,12 +179,7 @@ class TestParserLive:
         assert thumb.exists()
         assert thumb.is_file()
 
-        assert self.imagehash(thumb) == self.imagehash(
-            simple_txt_email_thumbnail_file,
-        ), (
-            f"Created thumbnail {thumb} differs from expected file "
-            f"{simple_txt_email_thumbnail_file}"
-        )
+        self.assert_thumbnails_similar(thumb, simple_txt_email_thumbnail_file)
 
     def test_tika_parse_successful(self, mail_parser: MailDocumentParser) -> None:
         """
@@ -255,7 +261,7 @@ class TestParserLive:
         THEN:
             - Gotenberg shall be called to generate the PDF
             - The archive PDF shall contain the expected content
-            - The generated thumbnail shall match the expected image hash
+            - The generated thumbnail shall be perceptually close to the expected image
         """
         util_call_with_backoff(mail_parser.parse, [html_email_file, "message/rfc822"])
 
@@ -272,14 +278,4 @@ class TestParserLive:
             html_email_file,
             "message/rfc822",
         )
-        generated_thumbnail_hash = self.imagehash(generated_thumbnail)
-
-        # The created PDF is not reproducible, but the converted image
-        # should always look the same
-        expected_hash = self.imagehash(html_email_thumbnail_file)
-
-        assert generated_thumbnail_hash == expected_hash, (
-            f"PDF thumbnail differs from expected. "
-            f"Generated: {generated_thumbnail}, "
-            f"Hash: {generated_thumbnail_hash} vs {expected_hash}"
-        )
+        self.assert_thumbnails_similar(generated_thumbnail, html_email_thumbnail_file)

src/paperless_ai/ai_classifier.py

@@ -7,6 +7,7 @@ from documents.models import Document
 from documents.permissions import permitted_object_ids
 from documents.permissions import restrict_queryset_to_visible
 from documents.permissions import user_is_unrestricted
+from documents.versioning import annotate_effective_content
 from paperless.config import AIConfig
 from paperless_ai.base_model import ClassificationSuggestions
 from paperless_ai.base_model import TaxonomyChoiceDict
@@ -113,7 +114,7 @@ def build_prompt_without_rag(
 ) -> str:
     filename = document.filename or ""
     content = truncate_content(
-        document.content[:4000] or "",
+        (document.get_effective_content() or "")[:4000],
         chunk_size=config.llm_embedding_chunk_size,
         context_size=config.llm_context_size,
     )
@@ -227,7 +228,9 @@ def get_taxonomy_context(
 
         # similar_documents is already ordered by descending weight; don't lose it.
         similar_document_ids = [s["document_id"] for s in similar_documents]
-        similar_documents_by_id = Document.objects.in_bulk(similar_document_ids)
+        similar_documents_by_id = annotate_effective_content(
+            Document.objects.all(),
+        ).in_bulk(similar_document_ids)
         similar_docs = [
             similar_documents_by_id[document_id]
             for document_id in similar_document_ids
@@ -235,7 +238,7 @@ def get_taxonomy_context(
         ][:max_docs]
         context_blocks = []
         for similar in similar_docs:
-            text = similar.content[:1000] or ""
+            text = (similar.get_effective_content() or "")[:1000]
             title = similar.title or similar.filename or "Untitled"
             context_blocks.append(f"TITLE: {title}\n{text}")
     except Exception:

src/paperless_ai/embedding.py

@@ -135,6 +135,6 @@ def build_llm_index_text(doc: Document) -> str:
         lines.append(f"Custom Field - {instance.field.name}: {instance}")
 
     lines.append("\nContent:\n")
-    lines.append(doc.content or "")
+    lines.append(doc.get_effective_content() or "")
 
     return _normalize_llm_index_text("\n".join(lines))

src/paperless_ai/indexing.py

@@ -17,6 +17,8 @@ from documents.models import PaperlessTask
 from documents.utils import IterWrapper
 from documents.utils import QuerySetStream
 from documents.utils import identity
+from documents.versioning import annotate_effective_content
+from documents.versioning import root_document_ids
 from paperless.config import AIConfig
 from paperless_ai.db import db_connection_released
 from paperless_ai.embedding import build_llm_index_text
@@ -443,11 +445,11 @@ def update_llm_index(
                 "Skipping LLM index update: migration check deferred; "
                 "will retry next run."
             )
-    documents = Document.objects.select_related(
-        "correspondent",
-        "document_type",
-        "storage_path",
-    ).prefetch_related("tags", "notes", "custom_fields__field")
+    documents = annotate_effective_content(
+        Document.objects.filter(root_document__isnull=True)
+        .select_related("correspondent", "document_type", "storage_path")
+        .prefetch_related("tags", "notes", "custom_fields__field"),
+    )
     no_documents = not documents.exists()
 
     # Fast exit before touching config: nothing to index and no existing index.
@@ -483,7 +485,7 @@ def update_llm_index(
             msg = "LLM index rebuilt successfully."
         else:
             scoped_documents = (
-                documents.filter(id__in=document_ids)
+                documents.filter(id__in=root_document_ids(document_ids))
                 if document_ids is not None
                 else documents
             )
@@ -510,7 +512,12 @@ def update_llm_index(
 
 
 def llm_index_add_or_update_document(document: Document):
-    """Add or atomically replace a document's chunks in the index."""
+    """
+    Add or atomically replace a document's chunks in the index. Only root
+    documents are indexed, so a version is indexed as its root document.
+    """
+    if document.root_document_id is not None:
+        document = document.root_document
     config = AIConfig()
     new_nodes = build_document_node(
         document,
@@ -688,7 +695,7 @@ def retrieve_similar_nodes(
     )
 
     query_text = truncate_embedding_query(
-        (document.title or "") + "\n" + (document.content or ""),
+        (document.title or "") + "\n" + (document.get_effective_content() or ""),
         chunk_size=config.llm_embedding_chunk_size,
     )
     # Hold the shared read lock for the whole retrieval so the connection is

src/paperless_ai/tests/test_ai_classifier.py

@@ -55,6 +55,7 @@ def mock_document():
     doc.storage_path = None
     doc.archive_serial_number = "12345"
     doc.content = "This is the document content."
+    doc.get_effective_content.return_value = "This is the document content."
 
     cf1 = MagicMock(__str__=lambda x: "Value1")
     cf1.field = MagicMock()
@@ -434,6 +435,55 @@ def test_get_taxonomy_context_preserves_similarity_order_and_distinct_documents(
     )
 
 
+@pytest.mark.django_db
+class TestClassifierEffectiveContent:
+    """A root document's text for the LLM is its newest version's content."""
+
+    @staticmethod
+    def _root_with_version() -> Document:
+        root = DocumentFactory(title="Statement", content="stale text")
+        DocumentFactory(root_document=root, version_index=1, content="latest text")
+        return root
+
+    def test_prompt_uses_the_newest_versions_content(self) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - The classification prompt is built for the root
+        THEN:
+            - It contains the newest version's content
+        """
+        prompt = build_prompt_without_rag(self._root_with_version(), AIConfig())
+
+        assert "latest text" in prompt
+        assert "stale text" not in prompt
+
+    @override_settings(LLM_EMBEDDING_BACKEND="huggingface")
+    def test_similar_document_context_uses_the_newest_versions_content(self) -> None:
+        """
+        GIVEN:
+            - A similar root document with a version
+        WHEN:
+            - The similar-document context is built
+        THEN:
+            - It contains the newest version's content
+        """
+        similar = self._root_with_version()
+        document = DocumentFactory(content="Some content")
+        fake_nodes = [
+            SimpleNamespace(metadata={"document_id": str(similar.pk)}, score=0.9),
+        ]
+
+        with patch(
+            "paperless_ai.ai_classifier.retrieve_similar_nodes",
+            return_value=fake_nodes,
+        ):
+            _candidates, context = get_taxonomy_context(document, user=None)
+
+        assert context == "TITLE: Statement\nlatest text"
+
+
 @pytest.mark.django_db
 @override_settings(LLM_EMBEDDING_BACKEND="huggingface")
 def test_get_taxonomy_context_no_similar_docs():

src/paperless_ai/tests/test_ai_indexing.py

@@ -388,6 +388,108 @@ def test_update_llm_index_partial_update(
     assert after[str(doc2.pk)] == before[str(doc2.pk)]
 
 
+@pytest.mark.django_db
+class TestLlmIndexVersions:
+    """The LLM index holds root documents only: a version is indexed as its root."""
+
+    def test_add_or_update_document_indexes_a_version_as_its_root(
+        self,
+        temp_llm_index_dir: Path,
+        mock_embed_model: FakeEmbedding,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - The version is passed to llm_index_add_or_update_document
+        THEN:
+            - Only the root document is in the index
+        """
+        root = DocumentFactory(content="root content")
+        version = DocumentFactory(root_document=root, version_index=1)
+
+        indexing.llm_index_add_or_update_document(version)
+
+        with indexing.get_vector_store() as store:
+            indexed = store.get_modified_times()
+
+        assert set(indexed) == {str(root.pk)}
+
+    def test_rebuild_skips_versions(
+        self,
+        temp_llm_index_dir: Path,
+        mock_embed_model: FakeEmbedding,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - The LLM index is rebuilt
+        THEN:
+            - Only the root document is in the index
+        """
+        root = DocumentFactory()
+        DocumentFactory(root_document=root, version_index=1)
+
+        indexing.update_llm_index(rebuild=True)
+
+        with indexing.get_vector_store() as store:
+            indexed = store.get_modified_times()
+
+        assert set(indexed) == {str(root.pk)}
+
+    def test_rebuild_indexes_the_newest_versions_content(
+        self,
+        temp_llm_index_dir: Path,
+        mock_embed_model: FakeEmbedding,
+        mocker: pytest_mock.MockerFixture,
+    ) -> None:
+        """
+        GIVEN:
+            - A root document with a version
+        WHEN:
+            - The LLM index is rebuilt
+        THEN:
+            - The root's text for the index is the version's content, answered
+              from the query rather than a query per document
+        """
+        root = DocumentFactory(content="stale text")
+        DocumentFactory(root_document=root, version_index=1, content="latest text")
+        spy = mocker.spy(indexing, "build_document_node")
+
+        indexing.update_llm_index(rebuild=True)
+
+        indexed = spy.call_args.args[0]
+        assert indexed.pk == root.pk
+        assert indexed.effective_content == "latest text"
+
+    def test_incremental_update_by_version_id_refreshes_the_root(
+        self,
+        temp_llm_index_dir: Path,
+        mock_embed_model: FakeEmbedding,
+    ) -> None:
+        """
+        GIVEN:
+            - An indexed root document with a version whose root was modified since
+        WHEN:
+            - An incremental update is scoped to the version's id
+        THEN:
+            - The root's entry is refreshed and no entry exists for the version
+        """
+        root = DocumentFactory()
+        version = DocumentFactory(root_document=root, version_index=1)
+        indexing.update_llm_index(rebuild=True)
+        Document.objects.filter(pk=root.pk).update(modified=timezone.now())
+        root.refresh_from_db()
+
+        indexing.update_llm_index(document_ids=[version.pk])
+
+        with indexing.get_vector_store() as store:
+            indexed = store.get_modified_times()
+
+        assert indexed == {str(root.pk): root.modified.isoformat()}
+
+
 @pytest.mark.django_db
 def test_add_or_update_document_updates_existing_entry(
     temp_llm_index_dir: Path,
@@ -637,6 +739,7 @@ class TestLlmIndexAddOrUpdateDocumentEmptyContent:
 
         doc = MagicMock(spec=Document)
         doc.id = 42
+        doc.root_document_id = None
         # Must not raise
         indexing.llm_index_add_or_update_document(doc)
 

src/paperless_ai/tests/test_embedding.py

@@ -12,6 +12,7 @@ from paperless_ai.embedding import _normalize_llm_index_text
 from paperless_ai.embedding import build_llm_index_text
 from paperless_ai.embedding import get_configured_model_name
 from paperless_ai.embedding import get_embedding_model
+from paperless_testing.factories import DocumentFactory
 
 
 @pytest.fixture
@@ -46,6 +47,7 @@ def mock_document():
     doc.correspondent.name = "Test Correspondent"
     doc.archive_serial_number = "12345"
     doc.content = "This is the document content."
+    doc.get_effective_content.return_value = "This is the document content."
 
     cf1 = MagicMock(__str__=lambda x: "Value1")
     cf1.field = MagicMock()
@@ -280,7 +282,7 @@ def test_build_llm_index_text(mock_document):
 
 
 def test_build_llm_index_text_normalizes_ocr_punctuation_runs(mock_document):
-    mock_document.content = (
+    mock_document.get_effective_content.return_value = (
         "Introduction ................................................ 7\n"
         "Hardware Limitation ________________________________________ 9\n"
         "Keep short punctuation like INV-100 and ellipses..."
@@ -294,6 +296,43 @@ def test_build_llm_index_text_normalizes_ocr_punctuation_runs(mock_document):
     assert "ellipses..." in result
 
 
+@pytest.mark.django_db
+class TestBuildLlmIndexTextVersions:
+    """A root document is indexed with its effective content, like in the search index."""
+
+    def test_root_uses_the_newest_versions_content(self) -> None:
+        """
+        GIVEN:
+            - A root document with two versions
+        WHEN:
+            - The LLM index text is built for the root
+        THEN:
+            - It contains the newest version's content and not the others'
+        """
+        root = DocumentFactory(content="stale text")
+        DocumentFactory(root_document=root, version_index=1, content="older text")
+        DocumentFactory(root_document=root, version_index=2, content="latest text")
+
+        text = build_llm_index_text(root)
+
+        assert "latest text" in text
+        assert "stale text" not in text
+        assert "older text" not in text
+
+    def test_root_without_versions_uses_its_own_content(self) -> None:
+        """
+        GIVEN:
+            - A root document without versions
+        WHEN:
+            - The LLM index text is built for it
+        THEN:
+            - It contains the document's own content
+        """
+        root = DocumentFactory(content="own text")
+
+        assert "own text" in build_llm_index_text(root)
+
+
 def test_normalize_llm_index_text_collapses_ocr_leaders_without_joining_lines():
     assert _normalize_llm_index_text("A........B\nC____D----E") == "A B\nC D E"