Fixed: USB drives mounted to folders are treated as different mounts

Closes #4147

src/NzbDrone.Common/Disk/DiskProviderBase.cs

@@ -339,7 +339,7 @@ namespace NzbDrone.Common.Disk
             }
         }
 
-        public string GetPathRoot(string path)
+        public virtual string GetPathRoot(string path)
         {
             Ensure.That(path, () => path).IsValidPath();
 

src/NzbDrone.Windows/Disk/DiskProvider.cs

@@ -26,6 +26,22 @@ namespace NzbDrone.Windows.Disk
         [return: MarshalAs(UnmanagedType.Bool)]
         private static extern bool CreateHardLink(string lpFileName, string lpExistingFileName, IntPtr lpSecurityAttributes);
 
+        public override IMount GetMount(string path)
+        {
+            var reparsePoint = GetReparsePoint(path);
+
+            return reparsePoint ?? base.GetMount(path);
+        }
+
+        public override string GetPathRoot(string path)
+        {
+            Ensure.That(path, () => path).IsValidPath();
+
+            var reparsePoint = GetReparsePoint(path);
+
+            return reparsePoint?.RootDirectory ?? base.GetPathRoot(path);
+        }
+
         public override long? GetAvailableSpace(string path)
         {
             Ensure.That(path, () => path).IsValidPath();
@@ -171,5 +187,23 @@ namespace NzbDrone.Windows.Disk
                 return false;
             }
         }
+
+        private IMount GetReparsePoint(string path)
+        {
+            var di = new DirectoryInfo(path);
+            var isReparsePoint = di.Attributes.HasFlag(FileAttributes.ReparsePoint);
+
+            while (!isReparsePoint && (di = di.Parent) != null)
+            {
+                isReparsePoint = di.Attributes.HasFlag(FileAttributes.ReparsePoint);
+            }
+
+            if (isReparsePoint)
+            {
+                return new FolderMount(di);
+            }
+
+            return null;
+        }
     }
 }

src/NzbDrone.Windows/Disk/FolderMount.cs

@@ -0,0 +1,38 @@
+using System.IO;
+using NzbDrone.Common.Disk;
+using NzbDrone.Common.Extensions;
+
+namespace NzbDrone.Windows.Disk
+{
+    public class FolderMount : IMount
+    {
+        private readonly DirectoryInfo _directoryInfo;
+
+        public FolderMount(DirectoryInfo directoryInfo)
+        {
+            _directoryInfo = directoryInfo;
+        }
+
+        public long AvailableFreeSpace => 0;
+
+        public string DriveFormat => "NTFS";
+
+        public DriveType DriveType => DriveType.Removable;
+
+        public bool IsReady => true;
+
+        public MountOptions MountOptions { get; private set; }
+
+        public string Name => _directoryInfo.Name;
+
+        public string RootDirectory => _directoryInfo.FullName;
+
+        public long TotalFreeSpace => 0;
+
+        public long TotalSize => 0;
+
+        public string VolumeLabel => _directoryInfo.Name;
+
+        public string VolumeName => Name;
+    }
+}