[DYN-7366] Fix CER crash on ConnectorViewModel (#15816)

reddyashish · web-flow · commit 171e23384505 · 2025-02-11T12:35:10.000-08:00
diff --git a/src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs b/src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs
@@ -1222,16 +1222,20 @@ public override void Dispose()
             {
                 NodeEnd.PropertyChanged -= nodeEndViewModel_PropertyChanged;
             }
-            ConnectorPinViewCollection.CollectionChanged -= HandleCollectionChanged;
 
-            workspaceViewModel.PropertyChanged -= WorkspaceViewModel_PropertyChanged;
-
-            foreach (var pin in ConnectorPinViewCollection.ToList())
+            if (ConnectorPinViewCollection != null)
             {
-                pin.RequestRedraw -= HandlerRedrawRequest;
-                pin.RequestSelect -= HandleRequestSelected;
+                ConnectorPinViewCollection.CollectionChanged -= HandleCollectionChanged;
+
+                foreach (var pin in ConnectorPinViewCollection.ToList())
+                {
+                    pin.RequestRedraw -= HandlerRedrawRequest;
+                    pin.RequestSelect -= HandleRequestSelected;
+                }
             }
 
+            workspaceViewModel.PropertyChanged -= WorkspaceViewModel_PropertyChanged;
+
             this.PropertyChanged -= ConnectorViewModelPropertyChanged;
             DiscardAllConnectorPinModels();
 
@@ -1451,17 +1455,27 @@ internal List<Point> CollectPinLocations()
         /// </summary>
         public void Redraw()
         {
-            if (this.ConnectorModel?.End != null && ConnectorPinViewCollection?.Count > 0)
+            try
             {
-                RedrawBezierManyPoints();
+                if (this.ConnectorModel != null && ConnectorPinViewCollection != null)
+                {
+                    if (this.ConnectorModel?.End != null && ConnectorPinViewCollection?.Count > 0)
+                    {
+                        RedrawBezierManyPoints();
+                    }
+                    else if (this.ConnectorModel?.End != null)
+                    {
+                        this.Redraw(this.ConnectorModel.End.Center);
+                    }
+                }
+
+                this.SetCollapsedByNodeViewModel();
+                RaisePropertyChanged(nameof(ZIndex));
             }
-            else if (this.ConnectorModel?.End != null)
+            catch (Exception ex)
             {
-                this.Redraw(this.ConnectorModel.End.Center);
+                workspaceViewModel.DynamoViewModel.Model.Logger.Log("Error when redrawing the connector: " + ex.StackTrace);
             }
-
-            this.SetCollapsedByNodeViewModel();
-            RaisePropertyChanged(nameof(ZIndex));
         }
 
         /// <summary>
