Fixed merge layers and undo document changes saved

PixiEditor/Models/DataHolders/Document/Document.Layers.cs

@@ -492,6 +492,8 @@ namespace PixiEditor.Models.DataHolders
 
             UndoManager.SquashUndoChanges(2, "Undo merge layers", false);
 
+            LayersChanged?.Invoke(this, new LayersChangedEventArgs(layer.GuidValue, LayerAction.Add));
+
             return layer;
         }
 

PixiEditor/ViewModels/SubViewModels/Main/UndoViewModel.cs

@@ -34,7 +34,10 @@ namespace PixiEditor.ViewModels.SubViewModels.Main
 
             //sometimes CanRedo gets changed after UndoRedoCalled invoke, so check again (normally this is checked by the relaycommand)
             if (CanRedo(null))
+            {
                 Owner.BitmapManager.ActiveDocument.UndoManager.Redo();
+                Owner.BitmapManager.ActiveDocument.ChangesSaved = false;
+            }
         }
 
         /// <summary>
@@ -47,7 +50,10 @@ namespace PixiEditor.ViewModels.SubViewModels.Main
 
             //sometimes CanUndo gets changed after UndoRedoCalled invoke, so check again (normally this is checked by the relaycommand)
             if (CanUndo(null))
+            {
                 Owner.BitmapManager.ActiveDocument.UndoManager.Undo();
+                Owner.BitmapManager.ActiveDocument.ChangesSaved = false;
+            }
         }
 
         /// <summary>