From d2b5bd0a441a85acbdd985346b09e109cd0b7c00 Mon Sep 17 00:00:00 2001
From: Lars Brubaker <larsbrubaker@gmail.com>
Date: Tue, 12 Dec 2017 18:18:39 -0800
Subject: [PATCH] try catch on long running task

don't crash subtract cancel
---
 ApplicationView/ApplicationController.cs           | 9 ++++++++-
 PartPreviewWindow/View3D/Actions/SubtractEditor.cs | 4 ++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/ApplicationView/ApplicationController.cs b/ApplicationView/ApplicationController.cs
index dd241129e..fb4df1281 100644
--- a/ApplicationView/ApplicationController.cs
+++ b/ApplicationView/ApplicationController.cs
@@ -1453,7 +1453,14 @@ namespace MatterHackers.MatterControl
 
 			return Task.Run(async () =>
 			{
-				await func?.Invoke(taskDetails, tokenSource.Token);
+				try
+				{
+					await func?.Invoke(taskDetails, tokenSource.Token);
+				}
+				catch
+				{
+
+				}
 
 				executingTasks.Remove(taskDetails);
 			});
diff --git a/PartPreviewWindow/View3D/Actions/SubtractEditor.cs b/PartPreviewWindow/View3D/Actions/SubtractEditor.cs
index 0bc35d0cd..f23e74067 100644
--- a/PartPreviewWindow/View3D/Actions/SubtractEditor.cs
+++ b/PartPreviewWindow/View3D/Actions/SubtractEditor.cs
@@ -192,6 +192,10 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
 								progressStatus.Progress0To1 = percentCompleted + amountPerOperation * csgStatus.Progress0To1;
 								reporter.Report(progressStatus);
 							}, cancelationToken);
+							if(cancelationToken.IsCancellationRequested)
+							{
+								return Task.CompletedTask;
+							}
 							var inverse = keep.WorldMatrix();
 							inverse.Invert();
 							transformedKeep.Transform(inverse);