Ignore duplicate sequence numbers

NearbyShare/Connection/NearbyConnection.swift

@@ -389,9 +389,17 @@ class NearbyConnection {
         let d2dMsg = try Securegcm_DeviceToDeviceMessage(serializedBytes: decryptedData)
         
         guard d2dMsg.hasMessage, d2dMsg.hasSequenceNumber else { throw NearbyError.requiredFieldMissing("d2dMessage.message|sequenceNumber") }
-        clientSeq += 1
+        let receivedSeq = d2dMsg.sequenceNumber
+        let expectedSeq = clientSeq + 1
         
-        guard d2dMsg.sequenceNumber == clientSeq else { throw NearbyError.protocolError("Wrong sequence number. Expected \(clientSeq), got \(d2dMsg.sequenceNumber)") }
+        if receivedSeq == expectedSeq {
+            clientSeq = receivedSeq
+        } else if receivedSeq <= clientSeq {
+            log("[NearbyConnection \(self.id)] Ignoring duplicate/stale frame sequence \(receivedSeq). Current sequence is \(clientSeq)")
+            return
+        } else {
+            throw NearbyError.protocolError("Wrong sequence number. Expected \(expectedSeq), got \(receivedSeq)")
+        }
         let offlineFrame = try Location_Nearby_Connections_OfflineFrame(serializedBytes: d2dMsg.message)
         
         if offlineFrame.hasV1, offlineFrame.v1.hasType, case .payloadTransfer = offlineFrame.v1.type {

ShareExtension/ShareViewController.swift

@@ -273,13 +273,14 @@ class ShareViewController: NSViewController, OutboundAppDelegate {
                     if #available(macOS 15.0, *) {
                         alert.informativeText = "TimeoutDescription".localized()
                         alert.addButton(withTitle: "TimeoutButton".localized())
+                        alert.addButton(withTitle: "CloseAlert".localized())
                     } else {
                         alert.informativeText = "TimeoutDescriptionLegacy".localized()
                         alert.addButton(withTitle: "TimeoutButtonLegacy".localized())
                     }
                     
-                    alert.beginSheetModal(for: self.view.window!) { _ in
-                        if #available(macOS 15.0, *) {
+                    alert.beginSheetModal(for: self.view.window!) { response in
+                        if #available(macOS 15.0, *), response == .alertFirstButtonReturn {
                             openPrivacyAndSecuritySettings()
                         }
                     }