feat(privacy): Finish takes in edits nobody signed once the person agrees (ADR 0019)

Finishing a partly readable studyset counts the edits a device without
the keys wrote readable while it was made private, by kind (flashcards,
notes, learning paths, PDFs, studysets), and asks: taken in, they are
sealed with the tree's key as the person's; left, they stay locked (the
short reading of 22 Oct, finding 11). In English and German. Tests on the
real gateways both ways, and of the dialog.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/learn/halkyon_learn_flutter/lib/l10n/app_de.arb

@@ -2076,6 +2076,21 @@
   "publishTagsSent": "Die Namen der Tags, die mitgehen und die die Instanz erfährt: {names}",
   "@publishTagsSent": {"placeholders": {"names": {"type": "String"}}},
   "publishTagsSentNone": "Es gehen keine Tags mit.",
+  "privacyAdoptTitle": "Unsignierte Änderungen übernehmen?",
+  "privacyAdoptBody": "Während es privat gemacht wurde, hat ein Gerät ohne deine Schlüssel es geändert: {parts}. Übernommen, werden sie als deine versiegelt; sonst bleiben sie gesperrt, wie alles, was die Instanz geschrieben haben könnte.",
+  "@privacyAdoptBody": {"placeholders": {"parts": {"type": "String"}}},
+  "privacyAdoptTake": "Übernehmen",
+  "privacyAdoptLeave": "Gesperrt lassen",
+  "privacyEditsCards": "{count, plural, =1{1 Karteikarte} other{{count} Karteikarten}}",
+  "@privacyEditsCards": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsNotes": "{count, plural, =1{1 Notiz} other{{count} Notizen}}",
+  "@privacyEditsNotes": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsPaths": "{count, plural, =1{1 Änderung an Lernpfaden} other{{count} Änderungen an Lernpfaden}}",
+  "@privacyEditsPaths": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsPdfs": "{count, plural, =1{1 PDF} other{{count} PDFs}}",
+  "@privacyEditsPdfs": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsStudysets": "{count, plural, =1{1 Lernset} other{{count} Lernsets}}",
+  "@privacyEditsStudysets": {"placeholders": {"count": {"type": "int"}}},
   "studysetLockedTitle": "Gesperrt",
   "studysetLockedBody": "Dieses Lernset ist privat, und sein Schlüssel öffnet sich auf diesem Gerät nicht: Es wurde mit Schlüsseln verschlüsselt, die dein Konto nicht mehr hat. Es lässt sich nur noch löschen.",
   "studysetVisibilityPartly": "Privat, teils lesbar",

apps/learn/halkyon_learn_flutter/lib/l10n/app_en.arb

@@ -2442,6 +2442,21 @@
   "publishTagsSent": "The names of the tags that go with it, which the instance learns: {names}",
   "@publishTagsSent": {"placeholders": {"names": {"type": "String"}}},
   "publishTagsSentNone": "No tags go with it.",
+  "privacyAdoptTitle": "Take in edits nobody signed?",
+  "privacyAdoptBody": "While it was made private, a device without your keys changed it: {parts}. Taken in, they are sealed as yours; left, they stay locked, as anything the instance could have written.",
+  "@privacyAdoptBody": {"placeholders": {"parts": {"type": "String"}}},
+  "privacyAdoptTake": "Take them in",
+  "privacyAdoptLeave": "Leave them locked",
+  "privacyEditsCards": "{count, plural, =1{1 flashcard} other{{count} flashcards}}",
+  "@privacyEditsCards": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsNotes": "{count, plural, =1{1 note} other{{count} notes}}",
+  "@privacyEditsNotes": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsPaths": "{count, plural, =1{1 change to learning paths} other{{count} changes to learning paths}}",
+  "@privacyEditsPaths": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsPdfs": "{count, plural, =1{1 PDF} other{{count} PDFs}}",
+  "@privacyEditsPdfs": {"placeholders": {"count": {"type": "int"}}},
+  "privacyEditsStudysets": "{count, plural, =1{1 studyset} other{{count} studysets}}",
+  "@privacyEditsStudysets": {"placeholders": {"count": {"type": "int"}}},
   "studysetLockedTitle": "Locked",
   "studysetLockedBody": "This studyset is private, and its key doesn't open on this device: it was encrypted with keys your account no longer has. It can only be deleted.",
   "studysetVisibilityPartly": "Private, partly readable",

apps/learn/halkyon_learn_flutter/lib/l10n/app_localizations.dart

@@ -12237,6 +12237,60 @@ abstract class AppLocalizations {
   /// **'No tags go with it.'**
   String get publishTagsSentNone;
 
+  /// No description provided for @privacyAdoptTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'Take in edits nobody signed?'**
+  String get privacyAdoptTitle;
+
+  /// No description provided for @privacyAdoptBody.
+  ///
+  /// In en, this message translates to:
+  /// **'While it was made private, a device without your keys changed it: {parts}. Taken in, they are sealed as yours; left, they stay locked, as anything the instance could have written.'**
+  String privacyAdoptBody(String parts);
+
+  /// No description provided for @privacyAdoptTake.
+  ///
+  /// In en, this message translates to:
+  /// **'Take them in'**
+  String get privacyAdoptTake;
+
+  /// No description provided for @privacyAdoptLeave.
+  ///
+  /// In en, this message translates to:
+  /// **'Leave them locked'**
+  String get privacyAdoptLeave;
+
+  /// No description provided for @privacyEditsCards.
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =1{1 flashcard} other{{count} flashcards}}'**
+  String privacyEditsCards(int count);
+
+  /// No description provided for @privacyEditsNotes.
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =1{1 note} other{{count} notes}}'**
+  String privacyEditsNotes(int count);
+
+  /// No description provided for @privacyEditsPaths.
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =1{1 change to learning paths} other{{count} changes to learning paths}}'**
+  String privacyEditsPaths(int count);
+
+  /// No description provided for @privacyEditsPdfs.
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =1{1 PDF} other{{count} PDFs}}'**
+  String privacyEditsPdfs(int count);
+
+  /// No description provided for @privacyEditsStudysets.
+  ///
+  /// In en, this message translates to:
+  /// **'{count, plural, =1{1 studyset} other{{count} studysets}}'**
+  String privacyEditsStudysets(int count);
+
   /// No description provided for @studysetLockedTitle.
   ///
   /// In en, this message translates to:

apps/learn/halkyon_learn_flutter/lib/l10n/app_localizations_de.dart

@@ -7759,6 +7759,75 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get publishTagsSentNone => 'Es gehen keine Tags mit.';
 
+  @override
+  String get privacyAdoptTitle => 'Unsignierte Änderungen übernehmen?';
+
+  @override
+  String privacyAdoptBody(String parts) {
+    return 'Während es privat gemacht wurde, hat ein Gerät ohne deine Schlüssel es geändert: $parts. Übernommen, werden sie als deine versiegelt; sonst bleiben sie gesperrt, wie alles, was die Instanz geschrieben haben könnte.';
+  }
+
+  @override
+  String get privacyAdoptTake => 'Übernehmen';
+
+  @override
+  String get privacyAdoptLeave => 'Gesperrt lassen';
+
+  @override
+  String privacyEditsCards(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Karteikarten',
+      one: '1 Karteikarte',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsNotes(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Notizen',
+      one: '1 Notiz',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsPaths(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Änderungen an Lernpfaden',
+      one: '1 Änderung an Lernpfaden',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsPdfs(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count PDFs',
+      one: '1 PDF',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsStudysets(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Lernsets',
+      one: '1 Lernset',
+    );
+    return '$_temp0';
+  }
+
   @override
   String get studysetLockedTitle => 'Gesperrt';
 

apps/learn/halkyon_learn_flutter/lib/l10n/app_localizations_en.dart

@@ -7686,6 +7686,75 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get publishTagsSentNone => 'No tags go with it.';
 
+  @override
+  String get privacyAdoptTitle => 'Take in edits nobody signed?';
+
+  @override
+  String privacyAdoptBody(String parts) {
+    return 'While it was made private, a device without your keys changed it: $parts. Taken in, they are sealed as yours; left, they stay locked, as anything the instance could have written.';
+  }
+
+  @override
+  String get privacyAdoptTake => 'Take them in';
+
+  @override
+  String get privacyAdoptLeave => 'Leave them locked';
+
+  @override
+  String privacyEditsCards(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count flashcards',
+      one: '1 flashcard',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsNotes(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count notes',
+      one: '1 note',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsPaths(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count changes to learning paths',
+      one: '1 change to learning paths',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsPdfs(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count PDFs',
+      one: '1 PDF',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String privacyEditsStudysets(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count studysets',
+      one: '1 studyset',
+    );
+    return '$_temp0';
+  }
+
   @override
   String get studysetLockedTitle => 'Locked';
 

apps/learn/halkyon_learn_flutter/lib/src/core/privacy/data/privacy.dart

@@ -508,6 +508,119 @@ class Privacy(
     return of;
   }
 
+  /// The edits in [studysetId]'s private scope written readable without the
+  /// account's signature (a device without the keys, while it was made
+  /// private), by kind (`cards`, `notes`, `paths`, `pdfs`, `studysets`):
+  /// locked until the person takes them in ([adoptUnsigned]).
+  Future<Map<String, int>> unsignedIn(String studysetId) async {
+    final ids = {for (final id in await scopeOf(studysetId)) _uuid(id)};
+    final counts = <String, int>{};
+    void count(String kind, String table, String id, Envelope e) {
+      if (e.keyId != null || e.payload.lengthInBytes == 0) {
+        return;
+      }
+      if (open(e, table: table, id: id) case Readable(trusted: false)) {
+        counts[kind] = (counts[kind] ?? 0) + 1;
+      }
+    }
+
+    for (final r in await protocol.Studyset.db.find(
+      _db,
+      where: (t) => t.id.inSet(ids) & t.keyId.equals(null),
+    )) {
+      count('studysets', 'studyset', r.id!.uuid, (
+        keyId: r.keyId,
+        nonce: r.nonce,
+        payload: r.payload,
+      ));
+    }
+    final cards = {
+      for (final card in await protocol.Card.db.find(
+        _db,
+        where: (t) => t.studysetId.inSet(ids),
+      ))
+        card.id!,
+    };
+    for (final r in await protocol.CardRevision.db.find(
+      _db,
+      where: (t) => t.cardId.inSet(cards) & t.keyId.equals(null),
+    )) {
+      count('cards', 'card_revision', r.id!.uuid, (
+        keyId: r.keyId,
+        nonce: r.nonce,
+        payload: r.payload,
+      ));
+    }
+    final notes = {
+      for (final note in await protocol.Note.db.find(
+        _db,
+        where: (t) => t.studysetId.inSet(ids),
+      ))
+        note.id!,
+    };
+    for (final r in await protocol.NoteRevision.db.find(
+      _db,
+      where: (t) => t.noteId.inSet(notes) & t.keyId.equals(null),
+    )) {
+      count('notes', 'note_revision', r.id!.uuid, (
+        keyId: r.keyId,
+        nonce: r.nonce,
+        payload: r.payload,
+      ));
+    }
+    final paths = await protocol.LearningPath.db.find(
+      _db,
+      where: (t) => t.studysetId.inSet(ids),
+    );
+    for (final r in paths) {
+      count('paths', 'learning_path', r.id!.uuid, (
+        keyId: r.keyId,
+        nonce: r.nonce,
+        payload: r.payload,
+      ));
+    }
+    final steps = {
+      for (final step in await protocol.LearningPathStep.db.find(
+        _db,
+        where: (t) => t.pathId.inSet({for (final path in paths) path.id!}),
+      ))
+        step.id!,
+    };
+    for (final r in await protocol.LearningPathStepRevision.db.find(
+      _db,
+      where: (t) => t.stepId.inSet(steps) & t.keyId.equals(null),
+    )) {
+      count('paths', 'learning_path_step_revision', r.id!.uuid, (
+        keyId: r.keyId,
+        nonce: r.nonce,
+        payload: r.payload,
+      ));
+    }
+    for (final r in await protocol.PdfSource.db.find(
+      _db,
+      where: (t) => t.studysetId.inSet(ids) & t.keyId.equals(null),
+    )) {
+      count('pdfs', 'pdf_source', r.id!.uuid, (
+        keyId: r.keyId,
+        nonce: r.nonce,
+        payload: r.payload,
+      ));
+    }
+    return counts;
+  }
+
+  /// Takes in the edits [unsignedIn] counts, once the person confirmed: they
+  /// are sealed with the tree's key as theirs. Returns how many rows or
+  /// files are still left.
+  Future<int> adoptUnsigned(String studysetId) async {
+    final keyId = _privateKeyOf(studysetId);
+    if (keyId == null || !keys.canEncrypt) {
+      throw const PrivacyRefused(PrivacyRefusal.keysMissing);
+    }
+    _unmovable.clear();
+    return await rekeyTree(studysetId, keyId, adopt: true);
+  }
+
   /// Whether anything in the studysets [ids] is sealed: a studyset, a card's
   /// or a note's revision, a path, a step's revision or a PDF. Publishing
   /// refuses on the device then, before any tag's name goes out (the short

apps/learn/halkyon_learn_flutter/lib/src/feature/studyset/data/studyset_gateway.dart

@@ -52,6 +52,13 @@ abstract interface class StudysetGateway() {
   /// account's keys (ADR 0019, D8).
   bool get canMakePrivate;
 
+  /// The edits in the private studyset [id] a device without the keys wrote
+  /// readable, by kind; locked until taken in.
+  Future<Map<String, int>> unsignedEditsOf(String id);
+
+  /// Seals the edits [unsignedEditsOf] counts as the person's.
+  Future<int> adoptUnsignedEdits(String id);
+
   /// Whether the account has keys this device doesn't hold: it writes
   /// nothing here that would be private, new studysets among them (the
   /// reading of 22 Oct).

apps/learn/halkyon_learn_flutter/lib/src/feature/studyset/data/studyset_repository.dart

@@ -131,6 +131,18 @@ class StudysetRepository(final StudysetGateway _gateway) {
   /// account's keys (ADR 0019, D8).
   bool get canMakePrivate => _gateway.canMakePrivate;
 
+  /// The edits in the private studyset [id] a device without the keys wrote
+  /// readable, by kind (the short reading of 22 Oct, finding 11).
+  Future<Map<String, int>> unsignedEditsOf(String id) =>
+      _gateway.unsignedEditsOf(id);
+
+  /// Takes those edits in as the person's, sealed.
+  Future<int> adoptUnsignedEdits(String id) async {
+    final left = await _gateway.adoptUnsignedEdits(id);
+    await _refresh();
+    return left;
+  }
+
   /// Whether the account has keys this device doesn't hold, so it makes no
   /// studyset here (the reading of 22 Oct).
   bool get keysMissing => _gateway.keysMissing;

apps/learn/halkyon_learn_flutter/lib/src/feature/studyset/data/sync_studyset_gateway.dart

@@ -215,6 +215,17 @@ class SyncStudysetGateway(
   @override
   bool get canMakePrivate => _privacy.keys.canEncrypt;
 
+  @override
+  Future<Map<String, int>> unsignedEditsOf(String id) =>
+      _privacy.unsignedIn(id);
+
+  @override
+  Future<int> adoptUnsignedEdits(String id) async {
+    final left = await _privacy.adoptUnsigned(id);
+    _sync.requestSync();
+    return left;
+  }
+
   @override
   bool get keysMissing =>
       !_privacy.keys.canEncrypt && _privacy.keys.accountHasKeys;

apps/learn/halkyon_learn_flutter/lib/src/feature/studyset/widget/studyset_privacy.dart

@@ -72,6 +72,18 @@ Future<void> applyStudysetPrivacy(
     );
     return;
   }
+  // Finishing: edits a device without the keys wrote meanwhile are taken in
+  // only once the person agreed, after seeing what they are (the short
+  // reading of 22 Oct).
+  if (private && studyset.isPrivate && studyset.isPartlyReadable) {
+    final unsigned = await studysets.unsignedEditsOf(studyset.id);
+    final total = unsigned.values.fold(0, (sum, n) => sum + n);
+    if (total > 0 &&
+        context.mounted &&
+        await confirmAdoptingEdits(context, unsigned)) {
+      await studysets.adoptUnsignedEdits(studyset.id);
+    }
+  }
   final locked = await studysets.setPrivate(studyset.id, private: private);
   if (locked > 0) {
     messenger.showSnackBar(
@@ -80,6 +92,43 @@ Future<void> applyStudysetPrivacy(
   }
 }
 
+/// Asks whether to take in [unsigned] edits (by kind) a device without the
+/// keys wrote while the studyset was made private: taken in, they are
+/// sealed as the person's; left, they stay locked.
+Future<bool> confirmAdoptingEdits(
+  BuildContext context,
+  Map<String, int> unsigned,
+) async {
+  final l10n = AppLocalizations.of(context);
+  final parts = [
+    if (unsigned['cards'] case final n? when n > 0) l10n.privacyEditsCards(n),
+    if (unsigned['notes'] case final n? when n > 0) l10n.privacyEditsNotes(n),
+    if (unsigned['paths'] case final n? when n > 0) l10n.privacyEditsPaths(n),
+    if (unsigned['pdfs'] case final n? when n > 0) l10n.privacyEditsPdfs(n),
+    if (unsigned['studysets'] case final n? when n > 0)
+      l10n.privacyEditsStudysets(n),
+  ];
+  return await showDialog<bool>(
+        context: context,
+        builder: (context) => AlertDialog(
+          icon: const Icon(LucideIcons.shieldAlert),
+          title: Text(l10n.privacyAdoptTitle),
+          content: Text(l10n.privacyAdoptBody(parts.join(', '))),
+          actions: [
+            TextButton(
+              onPressed: () => Navigator.of(context).pop(false),
+              child: Text(l10n.privacyAdoptLeave),
+            ),
+            FilledButton(
+              onPressed: () => Navigator.of(context).pop(true),
+              child: Text(l10n.privacyAdoptTake),
+            ),
+          ],
+        ),
+      ) ??
+      false;
+}
+
 /// What the person may do from [showStudysetPrivacy].
 enum PrivacyChoice() {
   makePrivate,

apps/learn/halkyon_learn_flutter/test/core/privacy/privacy_markers_test.dart

@@ -10,6 +10,7 @@ import 'package:halkyon_learn_flutter/src/feature/settings/model/person_settings
 import 'package:halkyon_learn_flutter/src/feature/studyset/model/studyset.dart';
 import 'package:halkyon_learn_flutter/src/feature/studyset/model/studyset_content.dart';
 import 'package:halkyon_learn_flutter/src/feature/studyset/widget/studyset_actions.dart';
+import 'package:halkyon_learn_flutter/src/feature/studyset/widget/studyset_privacy.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart';
 import 'package:material_ui/material_ui.dart';
 
@@ -128,4 +129,36 @@ void main() {
     expect(seen, 'studyset-1');
     expect(scope, (studysetId: 'studyset-1'));
   });
+
+  testWidgets('Finish asks before taking in edits nobody signed, saying how '
+      'many of each kind', (tester) async {
+    bool? answer;
+    await tester.pumpWidget(
+      MaterialApp(
+        localizationsDelegates: appLocalizationsDelegates,
+        home: Builder(
+          builder: (context) => TextButton(
+            onPressed: () async => answer = await confirmAdoptingEdits(
+              context,
+              {'cards': 2, 'notes': 1},
+            ),
+            child: const Text('finish'),
+          ),
+        ),
+      ),
+    );
+    await tester.tap(find.text('finish'));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('2 flashcards, 1 note'), findsOneWidget);
+    await tester.tap(find.text('Leave them locked'));
+    await tester.pumpAndSettle();
+    expect(answer, isFalse);
+
+    await tester.tap(find.text('finish'));
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('Take them in'));
+    await tester.pumpAndSettle();
+    expect(answer, isTrue);
+  });
 }

apps/learn/halkyon_learn_flutter/test/core/privacy/private_trees_test.dart

@@ -632,6 +632,60 @@ void main() {
       );
     });
 
+    group('Finish and edits nobody signed', () {
+      Future<(_Device, String, String)> planted() async {
+        final laptop = await device(account: alice);
+        final id = await privateStudyset(laptop, 'Diary');
+        final card = await laptop.cards.insertCard(
+          studysetId: id,
+          position: 'a0',
+          payload: cardPayload('mine'),
+        );
+        // A device without the keys edited the card meanwhile, readable.
+        await protocol.CardRevision.db.insertRow(
+          db,
+          protocol.CardRevision(
+            id: Privacy.newId(),
+            cardId: protocol.UuidValue.withValidation(card),
+            parents: const [],
+            authorId: const protocol.Uuid().v7obj(),
+            payload: cardPayload('from the keyless device'),
+          ),
+        );
+        return (laptop, id, card);
+      }
+
+      test('counts them by kind; left, they stay locked', () async {
+        final (laptop, id, card) = await planted();
+
+        expect(await laptop.privacy.unsignedIn(id), {'cards': 1});
+        await laptop.privacy.maintain();
+
+        expect(await sealed(card), isFalse);
+        expect(
+          [
+            for (final r in await laptop.cards.revisionsOf({card}))
+              if (r.payload.lengthInBytes > 0)
+                utf8.decode(Uint8List.sublistView(r.payload)),
+          ],
+          [contains('mine')],
+        );
+      });
+
+      test("taken in, they are sealed as the person's and shown", () async {
+        final (laptop, id, card) = await planted();
+
+        await laptop.privacy.adoptUnsigned(id);
+
+        expect(await sealed(card), isTrue);
+        expect(await laptop.privacy.unsignedIn(id), isEmpty);
+        expect([
+          for (final r in await laptop.cards.revisionsOf({card}))
+            utf8.decode(Uint8List.sublistView(r.payload)),
+        ], containsAll([contains('mine'), contains('keyless')]));
+      });
+    });
+
     test("a file that won't move is owed, the tree partly readable, and the "
         'upkeep goes on', () async {
       final files = _FailingFiles();

apps/learn/halkyon_learn_flutter/test/support/fake_studyset_gateway.dart

@@ -77,6 +77,23 @@ class FakeStudysetGateway() implements StudysetGateway {
   @override
   bool keysMissing = false;
 
+  /// The unsigned edits each studyset holds, by kind.
+  final unsigned = <String, Map<String, int>>{};
+
+  /// The studysets whose unsigned edits were taken in.
+  final adopted = <String>[];
+
+  @override
+  Future<Map<String, int>> unsignedEditsOf(String id) async =>
+      unsigned[id] ?? const {};
+
+  @override
+  Future<int> adoptUnsignedEdits(String id) async {
+    adopted.add(id);
+    unsigned.remove(id);
+    return 0;
+  }
+
   @override
   Future<int> setPrivate(String id, {required bool private}) async {
     final tree = {id};