Do NOT expire control messages in groups

SessionMessagingKit/Database/Models/DisappearingMessageConfiguration.swift

@@ -303,8 +303,8 @@ public extension DisappearingMessagesConfiguration {
                 isPreviousOff: isPreviousOff
             ),
             timestampMs: timestampMs,
-            expiresInSeconds: updatedConfiguration.durationSeconds,
-            expiresStartedAtMs: expiresStartedAtMs
+            expiresInSeconds: (threadVariant == .legacyGroup ? nil : updatedConfiguration.durationSeconds), // Do not expire this control message in legacy groups
+            expiresStartedAtMs: (threadVariant == .legacyGroup ? nil : expiresStartedAtMs)
         ).inserted(db)
         
         return interaction.id

SessionMessagingKit/Messages/Visible Messages/VisibleMessage.swift

@@ -225,7 +225,7 @@ public extension VisibleMessage {
     static func from(_ db: Database, interaction: Interaction) -> VisibleMessage {
         let linkPreview: LinkPreview? = try? interaction.linkPreview.fetchOne(db)
         
-        var visibleMessage: VisibleMessage = VisibleMessage(
+        let visibleMessage: VisibleMessage = VisibleMessage(
             sender: interaction.authorId,
             sentTimestamp: UInt64(interaction.timestampMs),
             recipient: (try? interaction.recipientStates.fetchOne(db))?.recipientId,

SessionMessagingKit/Sending & Receiving/Message Handling/MessageReceiver+ClosedGroups.swift

@@ -670,6 +670,7 @@ extension MessageReceiver {
         guard ClosedGroup.filter(id: threadId).isNotEmpty(db) else { return }
         
         // Insert the info message for this group control message
+        // Note: Control messages for legacy groups are not affected by disappearing messages setting
         _ = try Interaction(
             serverHash: message.serverHash,
             threadId: threadId,
@@ -680,9 +681,7 @@ extension MessageReceiver {
             timestampMs: (
                 message.sentTimestamp.map { Int64($0) } ??
                 SnodeAPI.currentOffsetTimestampMs()
-            ),
-            expiresInSeconds: message.expiresInSeconds,
-            expiresStartedAtMs: message.expiresStartedAtMs
+            )
         ).inserted(db)
     }
 }