Landscape orientation.

Signal/src/AppDelegate.m

@@ -957,6 +957,15 @@ static NSTimeInterval launchStartedAt;
         return UIInterfaceOrientationMaskAllButUpsideDown;
     }
 
+    if (![self.windowManager isAppWindow:window]) {
+        // iOS uses various windows for animations, transitions, etc.
+        // e.g. _UIInteractiveHighlightEffectWindow,
+        //      UITextEffectsWindow.
+        //
+        // We should be permissive with these windows.
+        return UIInterfaceOrientationMaskAllButUpsideDown;
+    }
+
     if (window == self.windowManager.menuActionsWindow) {
         return UIInterfaceOrientationMaskAllButUpsideDown;
     }

SignalMessaging/utils/OWSWindowManager.h

@@ -31,6 +31,8 @@ extern const UIWindowLevel UIWindowLevel_Background;
 
 - (void)setIsScreenBlockActive:(BOOL)isScreenBlockActive;
 
+- (BOOL)isAppWindow:(UIWindow *)window;
+
 #pragma mark - Message Actions
 
 @property (nonatomic, readonly) BOOL isPresentingMenuActions;

SignalMessaging/utils/OWSWindowManager.m

@@ -310,6 +310,14 @@ const UIWindowLevel UIWindowLevel_MessageActions(void)
     [self ensureWindowState];
 }
 
+- (BOOL)isAppWindow:(UIWindow *)window
+{
+    OWSAssertDebug(window);
+
+    return (window == self.rootWindow || window == self.returnToCallWindow || window == self.callViewWindow
+        || window == self.menuActionsWindow || window == self.screenBlockingWindow);
+}
+
 #pragma mark - Message Actions
 
 - (BOOL)isPresentingMenuActions