#261: Ignore USB GetDrives crash (#272)

some users have problems with their USB drive (hardware?) such that GetDrives throws an exception which if not caught, results in a fatal exception for Chorus

src/Chorus/UI/UsbDriveLocator.cs

@@ -1,10 +1,11 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.ComponentModel;
 using System.IO;
 using System.Threading;
 using System.Windows.Forms;
+using SIL.Reporting;
 
 namespace Chorus.UI
 {
@@ -58,24 +59,35 @@ public bool CanExtend(object extendee)
 
 		private void ScanForUsbDrives()
 		{
-			while (_keepRunning)
+			// https://github.com/sillsdev/chorus/issues/261
+			// some users have problems with their USB drive (hardware?) such that GetDrives throws
+			//	an exception, which if not caught, results in a fatal exception for Chorus
+			try
 			{
-				var usbRoots = new SIL.UsbDrive.RetrieveUsbDriveInfo().GetDrives()
-					.Select(u => u.RootDirectory.FullName);
-				// In Balsa, the boot device (SD Card or USB Stick) shows up as one of the
-				// drives and it shouldn't be used for S/R.  Balsa will be changed to
-				// include a .chorus-hidden file in the root paritions that should not be
-				// used for S/R.  A user can include this file in USB attached drive that
-				// they don't want Chorus to use.
-				var usbDrives = System.IO.DriveInfo.GetDrives()
-					.Where(d => usbRoots.Contains(d.RootDirectory.FullName) &&
-								d.RootDirectory.GetFiles(".chorus-hidden").Count() == 0);
-				lock (_usbDrives)
+				while (_keepRunning)
 				{
-					_usbDrives.Clear();
-					_usbDrives.AddRange(usbDrives);
+					var usbRoots = new SIL.UsbDrive.RetrieveUsbDriveInfo().GetDrives()
+						.Select(u => u.RootDirectory.FullName);
+					// In Balsa, the boot device (SD Card or USB Stick) shows up as one of the
+					// drives and it shouldn't be used for S/R.  Balsa will be changed to
+					// include a .chorus-hidden file in the root paritions that should not be
+					// used for S/R.  A user can include this file in USB attached drive that
+					// they don't want Chorus to use.
+					var usbDrives = System.IO.DriveInfo.GetDrives()
+						.Where(d => usbRoots.Contains(d.RootDirectory.FullName) &&
+									d.RootDirectory.GetFiles(".chorus-hidden").Count() == 0);
+					lock (_usbDrives)
+					{
+						_usbDrives.Clear();
+						_usbDrives.AddRange(usbDrives);
+					}
+
+					Thread.Sleep(3000); // check again after 3 second
 				}
-				Thread.Sleep(3000); // check again after 1 second
+			}
+			catch (Exception ex)
+			{
+				ErrorReport.ReportNonFatalException(ex);
 			}
 		}