Fixed homing-job cancellation behabiour: a cancelled homing-job resul…

…ts an a device status "Ready" instead of "Disconnected". Fixes #3

src/Core/Devices/Device.cs

@@ -86,6 +86,11 @@ protected IDeviceStatusIntermediateTransition StatusIntermediateTransition(Devic
 			return new DeviceStatusTransition(this, sourceStatus, intermediateStatus, sourceStatus);
 		}
 
+		protected IDeviceStatusTransition StatusFailableTransition(DeviceStatus sourceStatus, DeviceStatus openStatus, DeviceStatus failedStatus)
+		{
+			return new DeviceStatusTransition(this, sourceStatus, openStatus, sourceStatus, failedStatus);
+		}
+
 		protected IDeviceStatusTransition StatusTransition(DeviceStatus sourceStatus, DeviceStatus openStatus, DeviceStatus targetStatus)
 		{
 			return new DeviceStatusTransition(this, sourceStatus, openStatus, targetStatus);
@@ -107,22 +112,24 @@ private class DeviceStatusTransition : IDeviceStatusTransition
 			private DeviceStatus _sourceStatus;
 			private DeviceStatus _openStatus;
 			private DeviceStatus _targetStatus;
+			private DeviceStatus? _failedStatus;
 			private bool _commited;
 			private bool _disposed;
 
-			public DeviceStatusTransition(Device owner, DeviceStatus sourceStatus, DeviceStatus openStatus, DeviceStatus targetStatus)
+			public DeviceStatusTransition(Device owner, DeviceStatus sourceStatus, DeviceStatus openStatus, DeviceStatus targetStatus, DeviceStatus? failedstatus = null)
 			{
 				_owner = owner;
 				_sourceStatus = sourceStatus;
 				_openStatus = openStatus;
 				_targetStatus = targetStatus;
+				_failedStatus = failedstatus;
 			}
 
 			public void Dispose()
 			{
 				if (!_commited && !_disposed)
 				{
-					_owner.Status = _sourceStatus;
+					_owner.Status = _failedStatus ?? _sourceStatus;
 					_disposed = true;
 				}
 			}

src/Core/Devices/Serial/SerialDevice.cs

@@ -115,14 +115,15 @@ public override async Task DisconnectAsync(CancellationToken cancellationToken)
 
 		public override async Task HomingAsync(CancellationToken cancellationToken)
 		{
-			using (var tx = StatusIntermediateTransition(DeviceStatus.Ready, DeviceStatus.Executing))
+			using (var tx = StatusFailableTransition(DeviceStatus.Ready, DeviceStatus.Executing, DeviceStatus.Disconnected))
 			{
 				tx.Open();
 
 				try
 				{
 					await WriteCommand(new SimpleEngraverCommand(EngraverCommandType.HomeCenter), cancellationToken);
 					Position = new Point((int)(_configuration.WidthDots / 2), (int)(_configuration.HeightDots / 2));
+					tx.Commit();
 				}
 				catch
 				{