Fix: ensure remove inbox tag children on remove_inbox_tags

src/documents/serialisers.py

@@ -1256,20 +1256,26 @@ class DocumentSerializer(
                 if "tags" in validated_data
                 else []
             )
-            inbox_tags_not_being_added = Tag.objects.filter(is_inbox_tag=True).exclude(
-                id__in=tag_ids_being_added,
-            )
+            tags_being_added = Tag.objects.filter(id__in=tag_ids_being_added)
+            required_by_add_tags = set(tags_being_added)
+            for tag in tags_being_added:
+                required_by_add_tags.update(tag.get_ancestors())
+
+            # Remove its descendants too, except any that is being added in this same update
+            tags_to_remove = set()
+            for tag in Tag.objects.filter(is_inbox_tag=True):
+                if tag in required_by_add_tags:
+                    continue
+                tags_to_remove.add(tag)
+                tags_to_remove.update(tag.get_descendants())
+
             if "tags" in validated_data:
                 validated_data["tags"] = [
-                    tag
-                    for tag in validated_data["tags"]
-                    if tag not in inbox_tags_not_being_added
+                    tag for tag in validated_data["tags"] if tag not in tags_to_remove
                 ]
             else:
                 validated_data["tags"] = [
-                    tag
-                    for tag in instance.tags.all()
-                    if tag not in inbox_tags_not_being_added
+                    tag for tag in instance.tags.all() if tag not in tags_to_remove
                 ]
 
         if settings.AUDIT_LOG_ENABLED:

src/documents/tests/test_tag_hierarchy.py

@@ -2,6 +2,7 @@ from unittest import mock
 
 from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
+from rest_framework import status
 from rest_framework.test import APITestCase
 
 from documents import bulk_edit
@@ -108,6 +109,44 @@ class TestTagHierarchy(DirectoriesMixin, APITestCase):
         self.document.refresh_from_db()
         assert self.document.tags.count() == 0
 
+    def test_remove_inbox_tags_removes_nested_children(self) -> None:
+        inbox = Tag.objects.create(name="Inbox", is_inbox_tag=True)
+        nested = Tag.objects.create(name="Nested", tn_parent=inbox)
+        self.document.add_nested_tags([nested])
+
+        resp = self.client.patch(
+            f"/api/documents/{self.document.pk}/",
+            {"title": "new title", "remove_inbox_tags": True},
+            format="json",
+        )
+        assert resp.status_code == status.HTTP_200_OK
+        self.document.refresh_from_db()
+        assert self.document.tags.count() == 0
+
+        # A subsequent save must not re-add the inbox tag as an ancestor
+        resp = self.client.patch(
+            f"/api/documents/{self.document.pk}/",
+            {"title": "another title", "tags": [], "remove_inbox_tags": True},
+            format="json",
+        )
+        assert resp.status_code == status.HTTP_200_OK
+        self.document.refresh_from_db()
+        assert self.document.tags.count() == 0
+
+    def test_remove_inbox_tags_keeps_inbox_when_nested_child_added(self) -> None:
+        inbox = Tag.objects.create(name="Inbox", is_inbox_tag=True)
+        nested = Tag.objects.create(name="Nested", tn_parent=inbox)
+        self.document.add_nested_tags([inbox])
+
+        self.client.patch(
+            f"/api/documents/{self.document.pk}/",
+            {"tags": [nested.pk], "remove_inbox_tags": True},
+            format="json",
+        )
+        self.document.refresh_from_db()
+        tags = set(self.document.tags.values_list("pk", flat=True))
+        assert tags == {inbox.pk, nested.pk}
+
     def test_bulk_edit_respects_hierarchy(self) -> None:
         bulk_edit.add_tag([self.document.pk], self.child.pk)
         self.document.refresh_from_db()