From ad90a9c8f3419e08954310c6aaafecaca74505ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Burak=20Kaan=20K=C3=B6se?= <bkaankose@outlook.com>
Date: Sat, 15 Mar 2025 15:22:01 +0100
Subject: [PATCH] Fix: Sequence contains no elements while downloading Gmail
 messages.

---
 Wino.Core/Synchronizers/GmailSynchronizer.cs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/Wino.Core/Synchronizers/GmailSynchronizer.cs b/Wino.Core/Synchronizers/GmailSynchronizer.cs
index 0430930e..69583dab 100644
--- a/Wino.Core/Synchronizers/GmailSynchronizer.cs
+++ b/Wino.Core/Synchronizers/GmailSynchronizer.cs
@@ -708,13 +708,17 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
         await Task.WhenAll(batchProcessCallbacks).ConfigureAwait(false);
 
         // Try to update max history id.
-        var maxHistoryId = batchProcessCallbacks.Select(a => a.Result).Where(a => a?.HistoryId != null).Max(a => a.HistoryId.Value);
+        var historyIdMessages = batchProcessCallbacks.Select(a => a.Result).Where(a => a?.HistoryId != null);
 
-        if (maxHistoryId != 0)
+        if (historyIdMessages.Any())
         {
-            Account.SynchronizationDeltaIdentifier = await _gmailChangeProcessor.UpdateAccountDeltaSynchronizationIdentifierAsync(Account.Id, maxHistoryId.ToString()).ConfigureAwait(false);
-        }
+            var maxHistoryId = batchProcessCallbacks.Select(a => a.Result).Where(a => a?.HistoryId != null).Max(a => a.HistoryId.Value);
 
+            if (maxHistoryId != 0)
+            {
+                Account.SynchronizationDeltaIdentifier = await _gmailChangeProcessor.UpdateAccountDeltaSynchronizationIdentifierAsync(Account.Id, maxHistoryId.ToString()).ConfigureAwait(false);
+            }
+        }
     }
 
     /// <summary>