Fix group leaving bug

Signal/src/ViewControllers/ThreadSettings/OWSConversationSettingsViewController.m

@@ -34,6 +34,7 @@
 #import <SessionServiceKit/TSThread.h>
 
 @import ContactsUI;
+@import PromiseKit;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -1176,13 +1177,21 @@ const CGFloat kIconViewLength = 24;
 - (void)leaveGroup
 {
     TSGroupThread *gThread = (TSGroupThread *)self.thread;
-    TSOutgoingMessage *message =
-        [TSOutgoingMessage outgoingMessageInThread:gThread groupMetaMessage:TSGroupMetaMessageQuit expiresInSeconds:0];
 
-    [LKStorage writeSyncWithBlock:^(YapDatabaseReadWriteTransaction *_Nonnull transaction) {
-        [self.messageSenderJobQueue addMessage:message transaction:transaction];
-        [gThread leaveGroupWithTransaction:transaction];
-    } error:nil];
+    if (gThread.usesSharedSenderKeys) {
+        NSString *groupPublicKey = [LKGroupUtilities getDecodedGroupID:gThread.groupModel.groupId];
+        [LKStorage writeSyncWithBlock:^(YapDatabaseReadWriteTransaction *_Nonnull transaction) {
+            [[LKClosedGroupsProtocol leaveGroupWithPublicKey:groupPublicKey transaction:transaction] retainUntilComplete];
+        } error:nil];
+    } else {
+        TSOutgoingMessage *message =
+            [TSOutgoingMessage outgoingMessageInThread:gThread groupMetaMessage:TSGroupMetaMessageQuit expiresInSeconds:0];
+
+        [LKStorage writeSyncWithBlock:^(YapDatabaseReadWriteTransaction *_Nonnull transaction) {
+            [self.messageSenderJobQueue addMessage:message transaction:transaction];
+            [gThread leaveGroupWithTransaction:transaction];
+        } error:nil];
+    }
 
     [self.navigationController popViewControllerAnimated:YES];
 }

SignalServiceKit/src/Loki/Protocol/Closed Groups/ClosedGroupsProtocol.swift

@@ -128,6 +128,11 @@ public final class ClosedGroupsProtocol : NSObject {
         infoMessage.save(with: transaction)
     }
 
+    @objc(leaveGroupWithPublicKey:transaction:)
+    public static func objc_leave(_ groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> AnyPromise {
+        return AnyPromise.from(leave(groupPublicKey, using: transaction))
+    }
+
     public static func leave(_ groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
         let userPublicKey = UserDefaults.standard[.masterHexEncodedPublicKey] ?? getUserHexEncodedPublicKey()
         return removeMembers([ userPublicKey ], from: groupPublicKey, using: transaction)