Saves work on a probable fix

get_users_with_perms includes group members by default, so PDF actions such
as merge and split gave them direct grants on the new documents, which
outlived their group membership.

pyproject.toml

@@ -43,7 +43,7 @@ dependencies = [
   "drf-spectacular~=0.30",
   "drf-spectacular-sidecar>=2026.7.1,<2026.10",
   "drf-writable-nested~=0.7.1",
-  "filelock~=3.32.0",
+  "filelock>=3.32,<4.1",
   "flower>=2.0.1,<2.3",
   "gotenberg-client[httpx]~=1.0",
   "httpx-oauth~=0.17",

src/documents/bulk_edit.py

@@ -34,7 +34,6 @@ from documents.models import DocumentType
 from documents.models import PaperlessTask
 from documents.models import StoragePath
 from documents.models import Tag
-from documents.permissions import PermissionsSpec
 from documents.permissions import set_permissions_for_objects
 from documents.plugins.helpers import DocumentsStatusManager
 from documents.tasks import bulk_update_documents
@@ -446,7 +445,7 @@ def reprocess(doc_ids: list[int], *, remote_ocr: bool = False) -> Literal["OK"]:
 
 def set_permissions(
     doc_ids: list[int],
-    set_permissions: PermissionsSpec,
+    set_permissions: dict,
     *,
     owner: User | None = None,
     merge: bool = False,

src/documents/consumer.py

@@ -38,8 +38,7 @@ from documents.models import StoragePath
 from documents.models import Tag
 from documents.models import WorkflowTrigger
 from documents.parsers import ParseError
-from documents.permissions import PermissionsSpec
-from documents.permissions import set_permissions_for_objects
+from documents.permissions import set_permissions_for_object
 from documents.plugins.base import AlwaysRunPluginMixin
 from documents.plugins.base import ConsumeTaskPlugin
 from documents.plugins.base import NoCleanupPluginMixin
@@ -949,7 +948,7 @@ class ConsumerPlugin(
             or self.metadata.change_users is not None
             or self.metadata.change_groups is not None
         ):
-            permissions: PermissionsSpec = {
+            permissions = {
                 "view": {
                     "users": self.metadata.view_users or [],
                     "groups": self.metadata.view_groups or [],
@@ -959,7 +958,7 @@ class ConsumerPlugin(
                     "groups": self.metadata.change_groups or [],
                 },
             }
-            set_permissions_for_objects(permissions, Document, [document.pk])
+            set_permissions_for_object(permissions=permissions, object=document)
 
         if self.metadata.custom_fields:
             for field in CustomField.objects.filter(

src/documents/data_models.py

@@ -130,12 +130,14 @@ class DocumentMetadataOverrides:
             get_users_with_perms(
                 doc,
                 only_with_perms_in=["view_document"],
+                with_group_users=False,
             ).values_list("id", flat=True),
         )
         overrides.change_users = list(
             get_users_with_perms(
                 doc,
                 only_with_perms_in=["change_document"],
+                with_group_users=False,
             ).values_list("id", flat=True),
         )
         overrides.custom_fields = {

src/documents/management/commands/document_exporter.py

@@ -3,6 +3,7 @@ from itertools import islice
 from pathlib import Path
 from typing import TYPE_CHECKING
 from typing import Any
+from typing import Final
 
 from allauth.mfa.models import Authenticator
 from allauth.socialaccount.models import SocialAccount
@@ -70,6 +71,10 @@ from paperless.models import ApplicationConfiguration
 from paperless_mail.models import MailAccount
 from paperless_mail.models import MailRule
 
+# Derived names replace the original's extension with these suffixes
+THUMBNAIL_SUFFIX: Final[str] = "-thumbnail.webp"
+ARCHIVE_SUFFIX: Final[str] = "-archive.pdf"
+
 
 def serialize_queryset_batched(
     queryset: "QuerySet[Any]",
@@ -512,7 +517,12 @@ class Command(CryptMixin, PaperlessCommand):
                     counter=filename_counter,
                 )
             else:
-                base_name = document.get_public_filename(counter=filename_counter)
+                # Leave room for the longer of the derived name suffixes
+                base_name = document.get_public_filename(
+                    counter=filename_counter,
+                    max_bytes=Document.MAX_PUBLIC_FILENAME_BYTES
+                    - max(len(THUMBNAIL_SUFFIX), len(ARCHIVE_SUFFIX)),
+                )
 
             # The thumbnail and archive names are derived from the stem, so
             # uniqueness must hold without the original's extension
@@ -541,7 +551,7 @@ class Command(CryptMixin, PaperlessCommand):
         document_dict[EXPORTER_FILE_NAME] = original_arc
 
         if not self.no_thumbnail:
-            thumbnail_name = base_name.parent / (base_name.stem + "-thumbnail.webp")
+            thumbnail_name = base_name.parent / (base_name.stem + THUMBNAIL_SUFFIX)
             if self.use_folder_prefix:
                 thumbnail_name = Path("thumbnails") / thumbnail_name
             thumbnail_arc = thumbnail_name.as_posix()
@@ -550,7 +560,7 @@ class Command(CryptMixin, PaperlessCommand):
             thumbnail_arc = None
 
         if not self.no_archive and document.has_archive_version:
-            archive_name = base_name.parent / (base_name.stem + "-archive.pdf")
+            archive_name = base_name.parent / (base_name.stem + ARCHIVE_SUFFIX)
             if self.use_folder_prefix:
                 archive_name = Path("archive") / archive_name
             archive_arc = archive_name.as_posix()

src/documents/models.py

@@ -157,6 +157,8 @@ class StoragePath(MatchingModel):
 
 class Document(SoftDeleteModel, ModelWithOwner):  # type: ignore[django-manager-missing]
     MAX_STORED_FILENAME_LENGTH: Final[int] = 1024
+    # Per-component limit of common filesystems (ext4, XFS, btrfs, ZFS, APFS)
+    MAX_PUBLIC_FILENAME_BYTES: Final[int] = 255
 
     correspondent = models.ForeignKey(
         Correspondent,
@@ -484,28 +486,47 @@ class Document(SoftDeleteModel, ModelWithOwner):  # type: ignore[django-manager-
     def archive_file(self):
         return Path(self.archive_path).open("rb")
 
-    def get_public_filename(self, *, archive=False, counter=0, suffix=None) -> str:
+    def get_public_filename(
+        self,
+        *,
+        archive=False,
+        counter=0,
+        suffix=None,
+        max_bytes: int = MAX_PUBLIC_FILENAME_BYTES,
+    ) -> str:
         """
         Returns a sanitized filename for the document, not including any paths.
+
+        The name fits in max_bytes (UTF-8). A title that is too long is
+        shortened, so the counter, suffix and extension are always kept.
         """
         # Root owns metadata for all versions
         context_document = (
             self.root_document if self.root_document_id is not None else self
         )
-        result = str(context_document)
 
+        tail = ""
         if counter:
-            result += f"_{counter:02}"
+            tail += f"_{counter:02}"
 
         if suffix:
-            result += suffix
+            tail += suffix
 
         if archive:
-            result += ".pdf"
+            tail += ".pdf"
         else:
-            result += self.file_type
+            tail += self.file_type
 
-        return pathvalidate.sanitize_filename(result, replacement_text="-")
+        # sanitize_filename truncates from the end, which would cut off the
+        # counter and extension, so shorten the title before appending them
+        head_bytes = max_bytes - len(tail.encode())
+        head = str(context_document).encode()[:head_bytes].decode(errors="ignore")
+
+        return pathvalidate.sanitize_filename(
+            head + tail,
+            replacement_text="-",
+            max_len=max_bytes,
+        )
 
     @property
     def file_type(self):

src/documents/permissions.py

@@ -1,10 +1,4 @@
-from collections.abc import Iterable
-from collections.abc import Mapping
 from typing import Any
-from typing import Final
-from typing import Literal
-from typing import TypeAlias
-from typing import TypedDict
 from typing import TypeVar
 
 from django.contrib.auth.models import Group
@@ -26,29 +20,16 @@ from django.db.models.functions import Coalesce
 from guardian.core import ObjectPermissionChecker
 from guardian.models import GroupObjectPermission
 from guardian.models import UserObjectPermission
+from guardian.shortcuts import assign_perm
 from guardian.shortcuts import get_objects_for_user
+from guardian.shortcuts import get_users_with_perms
+from guardian.shortcuts import remove_perm
 from rest_framework.permissions import BasePermission
 from rest_framework.permissions import DjangoObjectPermissions
 
 from documents.models import Document
 from documents.versioning import get_root_document
 
-PermissionAction = Literal["view", "change"]
-PERMISSION_ACTIONS: Final[tuple[PermissionAction, ...]] = ("view", "change")
-
-
-class PermissionGrantees(TypedDict, total=False):
-    """
-    The user and group ids to grant one permission action to. A missing key
-    leaves that kind of grant untouched.
-    """
-
-    users: Iterable[int]
-    groups: Iterable[int]
-
-
-PermissionsSpec: TypeAlias = Mapping[PermissionAction, PermissionGrantees]
-
 
 class PaperlessObjectPermissions(DjangoObjectPermissions):
     """
@@ -123,10 +104,87 @@ def get_groups_with_only_permission(obj, codename):
     return Group.objects.filter(id__in=group_object_perm_group_ids).distinct()
 
 
+def set_permissions_for_object(
+    permissions: dict,
+    object,
+    *,
+    merge: bool = False,
+) -> None:
+    """
+    Set permissions for an object. The permissions are given as a mapping of actions
+    to a dict of user / group id lists, e.g.
+    {"view": {"users": [1], "groups": [2]}, "change": {"users": [], "groups": []}}.
+
+    If merge is True, the permissions are merged with the existing permissions and
+    no users or groups are removed. If False, the permissions are set to exactly
+    the given list of users and groups.
+    """
+
+    for action, entry in permissions.items():
+        permission = f"{action}_{object.__class__.__name__.lower()}"
+        if "users" in entry:
+            # users
+            users_to_add = User.objects.filter(id__in=entry["users"])
+            users_to_remove = (
+                get_users_with_perms(
+                    object,
+                    only_with_perms_in=[permission],
+                    with_group_users=False,
+                )
+                if not merge
+                else User.objects.none()
+            )
+            if users_to_add.exists() and users_to_remove.exists():
+                users_to_remove = users_to_remove.exclude(id__in=users_to_add)
+            if users_to_remove.exists():
+                for user in users_to_remove:
+                    remove_perm(permission, user, object)
+            if users_to_add.exists():
+                for user in users_to_add:
+                    assign_perm(permission, user, object)
+                    if action == "change":
+                        # change gives view too
+                        assign_perm(
+                            f"view_{object.__class__.__name__.lower()}",
+                            user,
+                            object,
+                        )
+        if "groups" in entry:
+            # groups
+            groups_to_add = Group.objects.filter(id__in=entry["groups"])
+            groups_to_remove = (
+                get_groups_with_only_permission(
+                    object,
+                    permission,
+                )
+                if not merge
+                else Group.objects.none()
+            )
+            if groups_to_add.exists() and groups_to_remove.exists():
+                groups_to_remove = groups_to_remove.exclude(id__in=groups_to_add)
+            if groups_to_remove.exists():
+                for group in groups_to_remove:
+                    remove_perm(permission, group, object)
+            if groups_to_add.exists():
+                for group in groups_to_add:
+                    assign_perm(permission, group, object)
+                    if action == "change":
+                        # change gives view too
+                        assign_perm(
+                            f"view_{object.__class__.__name__.lower()}",
+                            group,
+                            object,
+                        )
+
+
 def _resolve_permissions(codenames: set[str], ctype: ContentType) -> list[Permission]:
     """
-    Resolve ``codenames`` to Permission rows, raising for any that don't exist
-    so a bad action name fails loudly instead of granting nothing.
+    Resolves `codenames` to Permission rows, raising like the single-object
+    assign_perm() this bulk path replaces does (via a `.get()` internally)
+    if any codename doesn't exist. SetPermissionsSerializer rejects unknown
+    action names at the API, but a caller passing one directly would
+    otherwise get a plain `.filter()` that silently builds zero rows and
+    no-ops instead of reporting the bad input.
     """
     permission_objs = list(
         Permission.objects.filter(content_type=ctype, codename__in=codenames),
@@ -145,13 +203,16 @@ def _apply_bulk_permission_entry(
     perm_model: type[UserObjectPermission] | type[GroupObjectPermission],
     identity_model: type[User] | type[Group],
     identity_field: str,
-    ids: Iterable[int],
+    ids: list[int],
     codename: str,
     permission_objs: list[Permission],
     ctype: ContentType,
     object_pks: list[str],
     merge: bool,
 ) -> None:
+    # Only the ids are needed to build permission rows (via `<field>_id=`),
+    # so avoid fetching full User/Group rows for identities that may not
+    # even end up being granted anything new.
     add_ids = set(
         identity_model.objects.filter(id__in=ids).values_list("id", flat=True),
     )
@@ -189,26 +250,45 @@ def _apply_bulk_permission_entry(
         for pk in object_pks
         for identity_id in add_ids
     ]
-    # ignore_conflicts skips grants that already exist (unique constraint).
+    # ignore_conflicts skips only rows that already exist as an exact
+    # (identity, permission, object) match -- the same de-dup the
+    # underlying (user|group, permission, object_pk) unique constraint
+    # already enforces for the single-object assign_perm() this replaces,
+    # so it doesn't change what counts as "already granted". batch_size
+    # caps how many rows go into a single INSERT statement.
     perm_model.objects.bulk_create(rows, ignore_conflicts=True, batch_size=1000)
 
 
 def set_permissions_for_objects(
-    permissions: PermissionsSpec,
+    permissions: dict,
     model: type[Model],
     pks: QuerySet | list,
     *,
     merge: bool = False,
 ) -> None:
     """
-    Set the view/change grants for every object in ``pks``. With ``merge``,
-    the given users and groups are added; without it, each given action's
-    direct grants are replaced. Granting change also grants view, and an
-    action entry with neither key is left untouched.
+    Bulk equivalent of set_permissions_for_object: applies the same
+    permission changes to every object identified by `pks` at once.
 
-    guardian's bulk assign_perm is avoided because it skips the direct row
-    for anyone who already has access through a group, so revoking the group
-    later would silently remove access that was granted explicitly.
+    Takes a model + pks (rather than model instances) deliberately -- the
+    permission rows built below only ever need `pk`, `content_type`, and
+    identity ids, so callers shouldn't have to fetch full rows (with every
+    other field) just to hand them to this function.
+
+    Deliberately does not use guardian's queryset/list-aware assign_perm:
+    passing a list as the object routes to bulk_assign_perm, which skips
+    creating a direct permission row for anyone who already has the
+    permission via ANY group membership (it checks
+    ObjectPermissionChecker.has_perm, which is group-inheritance-aware) --
+    unlike the single-object assign_perm this replaces, which always
+    ensures a direct row via get_or_create regardless of group-derived
+    access. Losing that guarantee would mean a later revocation of the
+    group's grant silently strips access an admin explicitly asked to be
+    direct. Bulk-creating rows straight against the permission models
+    instead (see _apply_bulk_permission_entry) preserves the original
+    always-create-a-direct-row semantics while still batching every object
+    and every identity into one query per action, rather than one query per
+    (object, user) pair.
     """
     object_pks = [str(pk) for pk in pks]
     if not object_pks:  # pragma: no cover
@@ -217,9 +297,12 @@ def set_permissions_for_objects(
     model_name = model.__name__.lower()
     ctype = ContentType.objects.get_for_model(model)
 
-    # Resolve every action before writing, so a bad one can't leave the
-    # actions ahead of it applied.
-    permissions_by_action: dict[PermissionAction, list[Permission]] = {}
+    # Every action is resolved up front, before anything is written, so an
+    # unrecognized action name (see _resolve_permissions) aborts the whole
+    # call instead of leaving the actions ahead of it already applied.
+    # SetPermissionsSerializer rejects unknown actions at the API, so this
+    # guards any other caller.
+    permissions_by_action: dict[str, list[Permission]] = {}
     for action, entry in permissions.items():
         if "users" not in entry and "groups" not in entry:
             continue

src/documents/serialisers.py

@@ -78,16 +78,12 @@ from documents.models import WorkflowActionEmail
 from documents.models import WorkflowActionWebhook
 from documents.models import WorkflowTrigger
 from documents.parsers import is_mime_type_supported
-from documents.permissions import PERMISSION_ACTIONS
-from documents.permissions import PermissionAction
-from documents.permissions import PermissionGrantees
-from documents.permissions import PermissionsSpec
 from documents.permissions import get_document_count_filter_for_user
 from documents.permissions import get_groups_with_only_permission
 from documents.permissions import has_perms_owner_aware
 from documents.permissions import permitted_document_ids
 from documents.permissions import restrict_queryset_to_visible
-from documents.permissions import set_permissions_for_objects
+from documents.permissions import set_permissions_for_object
 from documents.regex import validate_regex_pattern
 from documents.templating.filepath import validate_filepath_template_and_render
 from documents.templating.utils import convert_format_str_to_template_format
@@ -215,6 +211,9 @@ class MatchingModelSerializer(serializers.ModelSerializer[Any]):
         return match
 
 
+PERMISSION_ACTIONS = ("view", "change")
+
+
 class SetPermissionsMixin:
     def _validate_user_ids(self, user_ids):
         users = User.objects.none()
@@ -236,10 +235,8 @@ class SetPermissionsMixin:
                 )
         return groups
 
-    def validate_set_permissions(self, set_permissions=None) -> PermissionsSpec:
-        permissions_dict: dict[PermissionAction, PermissionGrantees] = {
-            action: {} for action in PERMISSION_ACTIONS
-        }
+    def validate_set_permissions(self, set_permissions=None):
+        permissions_dict = {action: {} for action in PERMISSION_ACTIONS}
         if set_permissions is not None:
             for action in PERMISSION_ACTIONS:
                 if action in set_permissions:
@@ -247,18 +244,18 @@ class SetPermissionsMixin:
                         users = set_permissions[action]["users"]
                         permissions_dict[action]["users"] = self._validate_user_ids(
                             users,
-                        ).values_list("id", flat=True)
+                        )
                     if "groups" in set_permissions[action]:
                         groups = set_permissions[action]["groups"]
                         permissions_dict[action]["groups"] = self._validate_group_ids(
                             groups,
-                        ).values_list("id", flat=True)
+                        )
                 else:
                     del permissions_dict[action]
         return permissions_dict
 
-    def _set_permissions(self, permissions: PermissionsSpec, object) -> None:
-        set_permissions_for_objects(permissions, type(object), [object.pk])
+    def _set_permissions(self, permissions, object) -> None:
+        set_permissions_for_object(permissions, object)
 
 
 class SerializerWithPerms(serializers.Serializer[dict[str, Any]]):
@@ -3089,7 +3086,7 @@ class BulkEditObjectsSerializer(SerializerWithPerms, SetPermissionsMixin):
             )
         return objects
 
-    def _validate_permissions(self, permissions) -> PermissionsSpec:
+    def _validate_permissions(self, permissions) -> dict:
         return self.validate_set_permissions(
             permissions,
         )

src/documents/tests/test_bulk_edit.py

@@ -23,7 +23,6 @@ from documents.models import Document
 from documents.models import DocumentType
 from documents.models import StoragePath
 from documents.models import Tag
-from documents.permissions import PermissionsSpec
 from documents.permissions import set_permissions_for_objects
 from paperless_testing.dirs import DirectoriesMixin
 from paperless_testing.factories import DocumentFactory
@@ -446,7 +445,7 @@ class TestBulkEdit(DirectoriesMixin, TestCase):
 
         grant_object(self.group1, self.doc1, "view_document")
 
-        permissions: PermissionsSpec = {
+        permissions = {
             "view": {
                 "users": [self.user1.id, self.user2.id],
                 "groups": [self.group2.id],
@@ -489,7 +488,7 @@ class TestBulkEdit(DirectoriesMixin, TestCase):
         grant_object(self.user1, self.doc1, "view_document")
         grant_object(self.group1, self.doc1, "view_document")
 
-        permissions: PermissionsSpec = {
+        permissions = {
             "view": {
                 "users": [self.user2.id],
                 "groups": [self.group2.id],
@@ -540,7 +539,7 @@ class TestBulkEdit(DirectoriesMixin, TestCase):
               batched call rather than one call per (document, identity)
               pair
         """
-        permissions: PermissionsSpec = {
+        permissions = {
             "view": {
                 "users": [self.user1.id, self.user2.id],
                 "groups": [self.group2.id],
@@ -647,7 +646,7 @@ class TestBulkEdit(DirectoriesMixin, TestCase):
         """
         with self.assertRaises(Permission.DoesNotExist):
             set_permissions_for_objects(
-                {"not_a_real_action": {"users": [self.user1.id], "groups": []}},  # type: ignore[bad-assignment]
+                {"not_a_real_action": {"users": [self.user1.id], "groups": []}},
                 Document,
                 [self.doc1.pk],
             )
@@ -675,7 +674,7 @@ class TestBulkEdit(DirectoriesMixin, TestCase):
             set_permissions_for_objects(
                 {
                     "view": {"users": [self.user1.id], "groups": []},
-                    "not_a_real_action": {"users": [self.user1.id], "groups": []},  # type: ignore[bad-assignment]
+                    "not_a_real_action": {"users": [self.user1.id], "groups": []},
                 },
                 Document,
                 [self.doc1.pk],

src/documents/tests/test_consumer.py

@@ -34,8 +34,10 @@ from documents.tests.utils import GetConsumerMixin
 from paperless_mail.models import MailRule
 from paperless_testing.assertions import FileSystemAssertsMixin
 from paperless_testing.dirs import DirectoriesMixin
+from paperless_testing.factories import DocumentFactory
 from paperless_testing.factories import UserFactory
 from paperless_testing.fakes.progress import FakeProgressManager
+from paperless_testing.permissions import grant_object
 
 
 class _BaseNewStyleParser:
@@ -1683,6 +1685,32 @@ class TestMetadataOverrides(TestCase):
         self.assertEqual(base.actor_id, 2)
         self.assertEqual(base.version_label, "v2")
 
+    def test_from_document_copies_user_and_group_grants_separately(self) -> None:
+        """
+        GIVEN:
+            - A document with view and change granted directly to one user and
+              to a group with another user as a member
+        WHEN:
+            - Overrides are built from the document
+        THEN:
+            - The user lists hold only the directly granted user
+            - The group lists hold the group
+        """
+        direct_user = UserFactory()
+        group_member = UserFactory()
+        group = Group.objects.create(name="group")
+        group_member.groups.add(group)
+        document = DocumentFactory()
+        grant_object(direct_user, document, "view_document", "change_document")
+        grant_object(group, document, "view_document", "change_document")
+
+        overrides = DocumentMetadataOverrides.from_document(document)
+
+        self.assertEqual(overrides.view_users, [direct_user.pk])
+        self.assertEqual(overrides.change_users, [direct_user.pk])
+        self.assertEqual(overrides.view_groups, [group.pk])
+        self.assertEqual(overrides.change_groups, [group.pk])
+
 
 class TestBarcodeApplyDetectedASN(TestCase):
     """

src/documents/tests/test_document_model.py

@@ -4,6 +4,7 @@ from datetime import date
 from pathlib import Path
 from unittest import mock
 
+import pytest
 from django.test import TestCase
 from django.test import override_settings
 from faker import Faker
@@ -257,3 +258,77 @@ def test_suggestion_content() -> None:
     )
     doc.content = content_over_limit
     assert doc.suggestion_content == expected_cropped_content
+
+
+@pytest.mark.django_db
+class TestPublicFilenameLength:
+    @pytest.mark.parametrize(
+        ("title", "archive", "extension"),
+        [
+            pytest.param("a" * 300, False, ".jpg", id="ascii-original"),
+            pytest.param("a" * 300, True, ".pdf", id="ascii-archive"),
+            pytest.param("ä" * 200, False, ".jpg", id="multibyte-original"),
+        ],
+    )
+    def test_long_title_keeps_extension_within_limit(
+        self,
+        title: str,
+        *,
+        archive: bool,
+        extension: str,
+    ) -> None:
+        """
+        GIVEN:
+            - A document whose title alone is longer than 255 bytes
+        WHEN:
+            - The public file name is generated
+        THEN:
+            - The name fits in 255 bytes and still ends with the extension
+        """
+        doc = Document(mime_type="image/jpeg", title=title, created=date(2020, 12, 25))
+
+        name = doc.get_public_filename(archive=archive)
+
+        assert len(name.encode()) <= 255
+        assert name.endswith(extension)
+
+    def test_long_title_counters_give_distinct_names(self) -> None:
+        """
+        GIVEN:
+            - A document whose title alone is longer than 255 bytes
+        WHEN:
+            - Public file names are generated with increasing counters
+        THEN:
+            - Each counter produces a distinct name that keeps the counter
+        """
+        doc = Document(
+            mime_type="application/pdf",
+            title="ä" * 200,
+            created=date(2020, 12, 25),
+        )
+
+        names = [doc.get_public_filename(counter=counter) for counter in range(3)]
+
+        assert len(set(names)) == 3
+        assert names[1].endswith("_01.pdf")
+        assert all(len(name.encode()) <= 255 for name in names)
+
+    def test_max_bytes_bounds_name(self) -> None:
+        """
+        GIVEN:
+            - A document with a long title
+        WHEN:
+            - The public file name is generated with a smaller byte limit
+        THEN:
+            - The name fits in that limit and keeps the counter and extension
+        """
+        doc = Document(
+            mime_type="application/pdf",
+            title="a" * 300,
+            created=date(2020, 12, 25),
+        )
+
+        name = doc.get_public_filename(counter=1, max_bytes=100)
+
+        assert len(name.encode()) <= 100
+        assert name.endswith("_01.pdf")

src/documents/tests/test_management_exporter.py

@@ -1537,3 +1537,67 @@ class TestExportDerivedFileNameCollisions:
             assert (
                 target / record[EXPORTER_ARCHIVE_NAME]
             ).read_text() == f"archive {pk}"
+
+    def test_long_titles_export_within_file_name_limit(
+        self,
+        paperless_dirs: PaperlessDirs,
+        tmp_path: Path,
+    ) -> None:
+        """
+        GIVEN:
+            - Two documents with the same created date and the same title
+            - The title alone is longer than 255 bytes and contains umlauts
+        WHEN:
+            - The exporter runs
+        THEN:
+            - The export finishes with distinct original, thumbnail and archive names
+            - Every exported file name fits in 255 bytes
+            - Each exported file holds its own document's content
+        """
+        for pk in (1, 2):
+            (paperless_dirs.originals_dir / f"{pk:07}.pdf").write_bytes(
+                f"original {pk}".encode(),
+            )
+            (paperless_dirs.archive_dir / f"{pk:07}.pdf").write_bytes(
+                f"archive {pk}".encode(),
+            )
+            (paperless_dirs.thumbnail_dir / f"{pk:07}.webp").write_bytes(
+                f"thumbnail {pk}".encode(),
+            )
+            DocumentFactory(
+                pk=pk,
+                title="Bestellbestätigung " * 15,
+                created=date(2026, 10, 15),
+                filename=f"{pk:07}.pdf",
+                archive_filename=f"{pk:07}.pdf",
+                mime_type="application/pdf",
+            )
+
+        target = tmp_path / "export"
+        target.mkdir()
+        call_command(
+            "document_exporter",
+            str(target),
+            "--no-progress-bar",
+            skip_checks=True,
+        )
+
+        manifest = json.loads((target / "manifest.json").read_text())
+        records = {r["pk"]: r for r in manifest if r["model"] == "documents.document"}
+
+        for key in (
+            EXPORTER_FILE_NAME,
+            EXPORTER_THUMBNAIL_NAME,
+            EXPORTER_ARCHIVE_NAME,
+        ):
+            assert records[1][key] != records[2][key]
+
+        for pk in (1, 2):
+            record = records[pk]
+            for key, content in (
+                (EXPORTER_FILE_NAME, f"original {pk}"),
+                (EXPORTER_THUMBNAIL_NAME, f"thumbnail {pk}"),
+                (EXPORTER_ARCHIVE_NAME, f"archive {pk}"),
+            ):
+                assert len(Path(record[key]).name.encode()) <= 255
+                assert (target / record[key]).read_text() == content

src/documents/workflows/mutations.py

@@ -7,8 +7,7 @@ from documents.data_models import DocumentMetadataOverrides
 from documents.models import CustomFieldInstance
 from documents.models import Document
 from documents.models import WorkflowAction
-from documents.permissions import PermissionsSpec
-from documents.permissions import set_permissions_for_objects
+from documents.permissions import set_permissions_for_object
 from documents.templating.workflows import parse_w_workflow_placeholders
 
 logger = logging.getLogger("paperless.workflows.mutations")
@@ -74,7 +73,7 @@ def apply_assignment_to_document(
             action.has_assign_change_groups,
         ],
     ):
-        permissions: PermissionsSpec = {
+        permissions = {
             "view": {
                 "users": action.assign_view_users.values_list("id", flat=True),
                 "groups": action.assign_view_groups.values_list("id", flat=True),
@@ -84,10 +83,9 @@ def apply_assignment_to_document(
                 "groups": action.assign_change_groups.values_list("id", flat=True),
             },
         }
-        set_permissions_for_objects(
-            permissions,
-            Document,
-            [document.pk],
+        set_permissions_for_object(
+            permissions=permissions,
+            object=document,
             merge=True,
         )
 
@@ -245,14 +243,13 @@ def apply_removal_to_document(
         document.owner = None
 
     if action.remove_all_permissions:
-        permissions: PermissionsSpec = {
+        permissions = {
             "view": {"users": [], "groups": []},
             "change": {"users": [], "groups": []},
         }
-        set_permissions_for_objects(
-            permissions,
-            Document,
-            [document.pk],
+        set_permissions_for_object(
+            permissions=permissions,
+            object=document,
             merge=False,
         )
 

uv.lock

@@ -1272,11 +1272,11 @@ wheels = [
 
 [[package]]
 name = "filelock"
-version = "3.32.6"
+version = "4.0.12"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/38/46/126b1831dca12060d4a8296bf9c4fe5c93c4f22197fa239cb0cc82042bba/filelock-3.32.6.tar.gz", hash = "sha256:a3f55a18af3652a94d8f47d6055df434f254ca1d02ef2524850c6d249ca2512c", size = 225172, upload-time = "2026-09-08T22:57:11.528Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/53/e4/34efcb869715cf299e47d1ac7b2624d2bcb6f2d3dffc2f0abe8417f65ab2/filelock-4.0.12.tar.gz", hash = "sha256:cf42711a7ac791818b299fab0332a088c65aeeefa36290de98db92c434303b0c", size = 253880, upload-time = "2026-10-05T13:17:43.677Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/cc/06/4f138f618dbea66803291274f228f01daf29f306fe8b96bc30dab765df75/filelock-3.32.6-py3-none-any.whl", hash = "sha256:3f16ecd0117feae0dfc147e8c62eb5daeccd8bd800378c3ddf416de9b4feb6b1", size = 100189, upload-time = "2026-09-08T22:57:10.182Z" },
+    { url = "https://files.pythonhosted.org/packages/da/a1/b047e1c486a2c66283633b7dbb73872ca16ca1ce6a426f70d4d037fc8e1c/filelock-4.0.12-py3-none-any.whl", hash = "sha256:5f17ee83ecee8a6f3e389c75822fb70a1c2f0506b99438a6dffa1d56793588c8", size = 111732, upload-time = "2026-10-05T13:17:42.361Z" },
 ]
 
 [[package]]
@@ -3184,7 +3184,7 @@ requires-dist = [
     { name = "drf-spectacular", specifier = "~=0.30" },
     { name = "drf-spectacular-sidecar", specifier = ">=2026.7.1,<2026.10" },
     { name = "drf-writable-nested", specifier = "~=0.7.1" },
-    { name = "filelock", specifier = "~=3.32.0" },
+    { name = "filelock", specifier = ">=3.32,<4.1" },
     { name = "flower", specifier = ">=2.0.1,<2.3" },
     { name = "gotenberg-client", extras = ["httpx"], specifier = "~=1.0" },
     { name = "granian", extras = ["uvloop"], marker = "extra == 'webserver'", specifier = ">=2.7,<2.9" },