From 0f442a8f3b6afece7481f288cf886ec2965face1 Mon Sep 17 00:00:00 2001
From: npub1tquskdu6yc4h8l7xxtceculxw600grekeq0xg2ukqfrwl7vrzg3quz3gmp
 <58390b379a262b73ffc632f19c73e6769ef40f36c81e642b960246eff9831222@buzz.block.builderlab.xyz>
Date: Sun, 2 Aug 2026 19:56:19 -0700
Subject: [PATCH] fix(mobile): reconnect after backward clock jumps

Co-authored-by: Tom Brow <tomb@block.xyz>
Signed-off-by: Tom Brow <tomb@block.xyz>
---
 mobile/lib/shared/relay/relay_session.dart    |  8 ++-
 .../test/shared/relay/relay_session_test.dart | 57 +++++++++++++++++++
 2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/mobile/lib/shared/relay/relay_session.dart b/mobile/lib/shared/relay/relay_session.dart
index 1c5c305b4c..9e0f5180d5 100644
--- a/mobile/lib/shared/relay/relay_session.dart
+++ b/mobile/lib/shared/relay/relay_session.dart
@@ -422,9 +422,13 @@ class RelaySessionNotifier extends Notifier<SessionState> {
     _backgroundGraceTimer?.cancel();
     _backgroundGraceTimer = null;
 
+    final backgroundedDuration = backgroundedAt == null
+        ? null
+        : _now().difference(backgroundedAt);
     final backgroundedLongEnoughToRequireReconnect =
-        backgroundedAt != null &&
-        _now().difference(backgroundedAt) >= _backgroundGraceDuration;
+        backgroundedDuration != null &&
+        (backgroundedDuration.isNegative ||
+            backgroundedDuration >= _backgroundGraceDuration);
     if (!backgroundedLongEnoughToRequireReconnect &&
         state.status == SessionStatus.connected) {
       return;
diff --git a/mobile/test/shared/relay/relay_session_test.dart b/mobile/test/shared/relay/relay_session_test.dart
index 826e234400..270297d20f 100644
--- a/mobile/test/shared/relay/relay_session_test.dart
+++ b/mobile/test/shared/relay/relay_session_test.dart
@@ -546,6 +546,63 @@ void main() {
     },
   );
 
+  test(
+    'resume reconnects a stale connected session after a backward clock jump',
+    () async {
+      final sockets = <_ControlledRelaySocket>[];
+      final keychain = nostr.Keys.generate();
+      var now = DateTime(2026, 8, 2, 12);
+      final session = RelaySessionNotifier(
+        now: () => now,
+        socketFactory:
+            ({
+              required wsUrl,
+              required nsec,
+              required onMessage,
+              required onConnected,
+              required onDisconnected,
+            }) {
+              final socket = _ControlledRelaySocket(
+                wsUrl: wsUrl,
+                nsec: nsec,
+                onMessage: onMessage,
+                onConnected: onConnected,
+                onDisconnected: onDisconnected,
+              );
+              sockets.add(socket);
+              return socket;
+            },
+      );
+      final container = ProviderContainer(
+        overrides: [
+          relaySessionProvider.overrideWith(() => session),
+          relayConfigProvider.overrideWith(
+            () => _FakeRelayConfigNotifier(
+              baseUrl: 'https://relay.example',
+              nsec: keychain.nsec,
+            ),
+          ),
+          authProvider.overrideWith(() => _AuthenticatedAuthNotifier()),
+        ],
+      );
+      addTearDown(container.dispose);
+      await container.read(authProvider.future);
+      final subscription = container.listen(relaySessionProvider, (_, _) {});
+      addTearDown(subscription.close);
+      await Future<void>.delayed(Duration.zero);
+      sockets.single.connectSuccessfully();
+
+      session.onAppPaused();
+      now = now.subtract(const Duration(minutes: 5));
+      session.onAppResumed();
+      await Future<void>.delayed(Duration.zero);
+
+      expect(sockets, hasLength(2));
+      expect(sockets.first.disposeCalls, 1);
+      expect(session.state.status, SessionStatus.reconnecting);
+    },
+  );
+
   test('delivers the same live event to each matching subscription', () async {
     final session = RelaySessionNotifier();
     final firstEvents = <NostrEvent>[];