Fixed exception in MountCheck if RootDirectory cannot be found.

src/NzbDrone.Common.Test/PathExtensionFixture.cs

@@ -113,6 +113,7 @@ namespace NzbDrone.Common.Test
         [TestCase(@"C:\Test\", @"C:\Test\mydir")]
         [TestCase(@"C:\Test\", @"C:\Test\mydir\")]
         [TestCase(@"C:\Test", @"C:\Test\30.Rock.S01E01.Pilot.avi")]
+        [TestCase(@"C:\", @"C:\Test\30.Rock.S01E01.Pilot.avi")]
         public void path_should_be_parent(string parentPath, string childPath)
         {
             parentPath.AsOsAgnostic().IsParentPath(childPath.AsOsAgnostic()).Should().BeTrue();

src/NzbDrone.Common/Extensions/PathExtensions.cs

@@ -80,11 +80,11 @@ namespace NzbDrone.Common.Extensions
 
         public static bool IsParentPath(this string parentPath, string childPath)
         {
-            if (parentPath != "/")
+            if (parentPath != "/" && !parentPath.EndsWith(":\\"))
             {
                 parentPath = parentPath.TrimEnd(Path.DirectorySeparatorChar);
             }
-            if (childPath != "/")
+            if (childPath != "/" && !parentPath.EndsWith(":\\"))
             {
                 childPath = childPath.TrimEnd(Path.DirectorySeparatorChar);
             }

src/NzbDrone.Core/HealthCheck/Checks/MountCheck.cs

@@ -21,8 +21,8 @@ namespace NzbDrone.Core.HealthCheck.Checks
             // Not best for optimization but due to possible symlinks and junctions, we get mounts based on series path so internals can handle mount resolution.
             var mounts = _seriesService.GetAllSeries()
                                        .Select(series => _diskProvider.GetMount(series.Path))
+                                       .Where(m => m != null && m.MountOptions != null && m.MountOptions.IsReadOnly)
                                        .DistinctBy(m => m.RootDirectory)
-                                       .Where(m => m.MountOptions != null && m.MountOptions.IsReadOnly)
                                        .ToList();
 
             if (mounts.Any())