fix minor issues

Session/Calls/Views & Modals/IncomingCallBanner.swift

@@ -167,7 +167,7 @@ final class IncomingCallBanner: UIView, UIGestureRecognizerDelegate {
         self.alpha = 0.0
         let window = CurrentAppContext().mainWindow!
         window.addSubview(self)
-        let topMargin = UIApplication.shared.keyWindow!.safeAreaInsets.top - Values.smallSpacing
+        let topMargin = window.safeAreaInsets.top - Values.smallSpacing
         self.autoPinWidthToSuperview(withMargin: Values.smallSpacing)
         self.autoPinEdge(toSuperviewEdge: .top, withInset: topMargin)
         UIView.animate(withDuration: 0.5, delay: 0, options: [], animations: {

Session/Conversations/Message Cells/VisibleMessageCell.swift

@@ -207,8 +207,7 @@ final class VisibleMessageCell : MessageCell, LinkPreviewViewDelegate {
     // MARK: Updating
     override func update() {
         guard let viewItem = viewItem, let message = viewItem.interaction as? TSMessage else { return }
-        let thread = message.thread
-        let isGroupThread = thread.isGroupThread()
+        let isGroupThread = viewItem.isGroupThread
         // Profile picture view
         profilePictureViewLeftConstraint.constant = isGroupThread ? VisibleMessageCell.groupThreadHSpacing : 0
         profilePictureViewWidthConstraint.constant = isGroupThread ? VisibleMessageCell.profilePictureSize : 0
@@ -217,8 +216,8 @@ final class VisibleMessageCell : MessageCell, LinkPreviewViewDelegate {
         if let senderSessionID = senderSessionID {
             profilePictureView.update(for: senderSessionID)
         }
-        if let thread = thread as? TSGroupThread, thread.isOpenGroup, let senderSessionID = senderSessionID {
-            if let openGroupV2 = Storage.shared.getV2OpenGroup(for: thread.uniqueId!) {
+        if let senderSessionID = senderSessionID, message.isOpenGroupMessage {
+            if let openGroupV2 = Storage.shared.getV2OpenGroup(for: message.uniqueThreadId) {
                 let isUserModerator = OpenGroupAPIV2.isUserModerator(senderSessionID, for: openGroupV2.room, on: openGroupV2.server)
                 moderatorIconImageView.isHidden = !isUserModerator || profilePictureView.isHidden
             } else {

Session/Open Groups/JoinOpenGroupVC.swift

@@ -143,7 +143,7 @@ final class JoinOpenGroupVC : BaseVC, UIPageViewControllerDataSource, UIPageView
             Storage.shared.write { transaction in
                 OpenGroupManagerV2.shared.add(room: room, server: server, publicKey: publicKey, using: transaction)
                 .done(on: DispatchQueue.main) { [weak self] _ in
-                    self?.presentingViewController!.dismiss(animated: true, completion: nil)
+                    self?.presentingViewController?.dismiss(animated: true, completion: nil)
                     let appDelegate = UIApplication.shared.delegate as! AppDelegate
                     appDelegate.forceSyncConfigurationNowIfNeeded().retainUntilComplete() // FIXME: It's probably cleaner to do this inside addOpenGroup(...)
                 }