Fixed: Prevent root folders from being added under the startup folder

src/NzbDrone.Api/RootFolders/RootFolderModule.cs

@@ -16,7 +16,8 @@ namespace NzbDrone.Api.RootFolders
                                 RootFolderValidator rootFolderValidator,
                                 PathExistsValidator pathExistsValidator,
                                 DroneFactoryValidator droneFactoryValidator,
-                                MappedNetworkDriveValidator mappedNetworkDriveValidator)
+                                MappedNetworkDriveValidator mappedNetworkDriveValidator,
+                                StartupFolderValidator startupFolderValidator)
             : base(signalRBroadcaster)
         {
             _rootFolderService = rootFolderService;
@@ -32,6 +33,7 @@ namespace NzbDrone.Api.RootFolders
                            .SetValidator(rootFolderValidator)
                            .SetValidator(droneFactoryValidator)
                            .SetValidator(mappedNetworkDriveValidator)
+                           .SetValidator(startupFolderValidator)
                            .SetValidator(pathExistsValidator);
         }
 

src/NzbDrone.Core/NzbDrone.Core.csproj

@@ -1032,6 +1032,7 @@
     <Compile Include="Validation\Paths\DroneFactoryValidator.cs" />
     <Compile Include="Validation\Paths\PathExistsValidator.cs" />
     <Compile Include="Validation\Paths\PathValidator.cs" />
+    <Compile Include="Validation\Paths\StartupFolderValidator.cs" />
     <Compile Include="Validation\Paths\RootFolderValidator.cs" />
     <Compile Include="Validation\Paths\SeriesAncestorValidator.cs" />
     <Compile Include="Validation\Paths\SeriesExistsValidator.cs" />

src/NzbDrone.Core/Validation/Paths/StartupFolderValidator.cs

@@ -0,0 +1,25 @@
+using FluentValidation.Validators;
+using NzbDrone.Common.EnvironmentInfo;
+using NzbDrone.Common.Extensions;
+
+namespace NzbDrone.Core.Validation.Paths
+{
+    public class StartupFolderValidator : PropertyValidator
+    {
+        private readonly IAppFolderInfo _appFolderInfo;
+        
+
+        public StartupFolderValidator(IAppFolderInfo appFolderInfo)
+            : base("Path cannot be an ancestor of the start up folder")
+        {
+            _appFolderInfo = appFolderInfo;
+        }
+
+        protected override bool IsValid(PropertyValidatorContext context)
+        {
+            if (context.PropertyValue == null) return true;
+
+            return !_appFolderInfo.StartUpFolder.IsParentPath(context.PropertyValue.ToString());
+        }
+    }
+}