Merge pull request #397 from mpretty-cyro/fix/config-push-crash

Fix a config push crash

SessionMessagingKit/LibSession/LibSession+SessionMessagingKit.swift

@@ -608,15 +608,8 @@ public extension LibSession {
                     // Only generate the push data if we need to do a push
                     guard config.needsPush else { return }
                     
-                    guard let data: PendingChanges.PushData = config.push(variant: info.variant) else {
-                        throw LibSessionError(
-                            config,
-                            fallbackError: .unableToGeneratePushData,
-                            logMessage: "Failed to generate push data for \(info.variant) config data, size: \(config.countDescription), error"
-                        )
-                    }
-                    
-                    result.append(data: data)
+                    // Try to generate the push data (will throw if there is an error)
+                    try result.append(data: config.push(variant: info.variant))
                 }
         }
         

SessionMessagingKit/LibSession/Types/Config.swift

@@ -124,12 +124,22 @@ public extension LibSession {
         
         // MARK: - Functions
         
-        func push(variant: ConfigDump.Variant) -> PendingChanges.PushData? {
+        func push(variant: ConfigDump.Variant) throws -> PendingChanges.PushData? {
             switch self {
                 case .userProfile(let conf), .contacts(let conf),
                     .convoInfoVolatile(let conf), .userGroups(let conf),
                     .groupInfo(let conf), .groupMembers(let conf):
-                    let cPushData: UnsafeMutablePointer<config_push_data> = config_push(conf)
+                    /// The `config_push` function implicitly unwraps it's value but can throw internally so call it in a guard
+                    /// statement to prevent the implicit unwrap from causing a crash (ideally it would return a standard optional
+                    /// so the compiler would warn us but it's not that straight forward when dealing with C)
+                    guard let cPushData: UnsafeMutablePointer<config_push_data> = config_push(conf) else {
+                        throw LibSessionError(
+                            self,
+                            fallbackError: .unableToGeneratePushData,
+                            logMessage: "Failed to generate push data for \(variant) config data, size: \(countDescription), error"
+                        )
+                    }
+                    
                     let pushData: Data = Data(
                         bytes: cPushData.pointee.config,
                         count: cPushData.pointee.config_len