Fixed: Mono internals does not properly copy/move symlinks, but instead copies the contents.

src/NzbDrone.Common/Disk/DiskProviderBase.cs

@@ -200,6 +200,11 @@ namespace NzbDrone.Common.Disk
                 throw new IOException(string.Format("Source and destination can't be the same {0}", source));
             }
 
+            CopyFileInternal(source, destination, overwrite);
+        }
+
+        protected virtual void CopyFileInternal(string source, string destination, bool overwrite = false)
+        {
             File.Copy(source, destination, overwrite);
         }
 
@@ -219,6 +224,11 @@ namespace NzbDrone.Common.Disk
             }
 
             RemoveReadOnly(source);
+            MoveFileInternal(source, destination);
+        }
+
+        protected virtual void MoveFileInternal(string source, string destination)
+        {
             File.Move(source, destination);
         }
 

src/NzbDrone.Mono.Test/DiskProviderTests/DiskProviderFixture.cs

@@ -1,4 +1,6 @@
 using System;
+using System.IO;
+using FluentAssertions;
 using Mono.Unix;
 using NUnit.Framework;
 using NzbDrone.Common.Test.DiskTests;
@@ -35,5 +37,55 @@ namespace NzbDrone.Mono.Test.DiskProviderTests
                 entry.FileAccessPermissions &= ~(FileAccessPermissions.UserWrite | FileAccessPermissions.GroupWrite | FileAccessPermissions.OtherWrite);
             }
         }
+
+        [Test]
+        public void should_move_symlink()
+        {
+            var tempFolder = GetTempFilePath();
+            Directory.CreateDirectory(tempFolder);
+
+            var file = Path.Combine(tempFolder, "target.txt");
+            var source = Path.Combine(tempFolder, "symlink_source.txt");
+            var destination = Path.Combine(tempFolder, "symlink_destination.txt");
+
+            File.WriteAllText(file, "Some content");
+
+            new UnixSymbolicLinkInfo(source).CreateSymbolicLinkTo(file);
+
+            Subject.MoveFile(source, destination);
+
+            File.Exists(file).Should().BeTrue();
+            File.Exists(source).Should().BeFalse();
+            File.Exists(destination).Should().BeTrue();
+            UnixFileSystemInfo.GetFileSystemEntry(destination).IsSymbolicLink.Should().BeTrue();
+
+            File.ReadAllText(destination).Should().Be("Some content");
+        }
+
+        [Test]
+        public void should_copy_symlink()
+        {
+            var tempFolder = GetTempFilePath();
+            Directory.CreateDirectory(tempFolder);
+
+            var file = Path.Combine(tempFolder, "target.txt");
+            var source = Path.Combine(tempFolder, "symlink_source.txt");
+            var destination = Path.Combine(tempFolder, "symlink_destination.txt");
+
+            File.WriteAllText(file, "Some content");
+
+            new UnixSymbolicLinkInfo(source).CreateSymbolicLinkTo(file);
+
+            Subject.CopyFile(source, destination);
+
+            File.Exists(file).Should().BeTrue();
+            File.Exists(source).Should().BeTrue();
+            File.Exists(destination).Should().BeTrue();
+            UnixFileSystemInfo.GetFileSystemEntry(source).IsSymbolicLink.Should().BeTrue();
+            UnixFileSystemInfo.GetFileSystemEntry(destination).IsSymbolicLink.Should().BeTrue();
+
+            File.ReadAllText(source).Should().Be("Some content");
+            File.ReadAllText(destination).Should().Be("Some content");
+        }
     }
 }

src/NzbDrone.Mono/Disk/DiskProvider.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -96,11 +96,88 @@ namespace NzbDrone.Mono.Disk
             return mount?.TotalSize;
         }
 
+        protected override void CopyFileInternal(string source, string destination, bool overwrite)
+        {
+            var sourceInfo = UnixFileSystemInfo.GetFileSystemEntry(source);
+
+            if (sourceInfo.IsSymbolicLink)
+            {
+                var isSameDir = UnixPath.GetDirectoryName(source) == UnixPath.GetDirectoryName(destination);
+                var symlinkInfo = (UnixSymbolicLinkInfo)sourceInfo;
+                var symlinkPath = symlinkInfo.ContentsPath;
+
+                var newFile = new UnixSymbolicLinkInfo(destination);
+
+                if (FileExists(destination) && overwrite)
+                {
+                    DeleteFile(destination);
+                }
+
+                if (isSameDir)
+                { // We're in the same dir, so we can preserve relative symlinks.
+                    newFile.CreateSymbolicLinkTo(symlinkInfo.ContentsPath);
+                }
+                else
+                {
+                    var fullPath = UnixPath.Combine(UnixPath.GetDirectoryName(source), symlinkPath);
+                    newFile.CreateSymbolicLinkTo(fullPath);
+                }
+            }
+            else
+            {
+                base.CopyFileInternal(source, destination, overwrite);
+            }
+        }
+
+        protected override void MoveFileInternal(string source, string destination)
+        {
+            var sourceInfo = UnixFileSystemInfo.GetFileSystemEntry(source);
+
+            if (sourceInfo.IsSymbolicLink)
+            {
+                var isSameDir = UnixPath.GetDirectoryName(source) == UnixPath.GetDirectoryName(destination);
+                var symlinkInfo = (UnixSymbolicLinkInfo)sourceInfo;
+                var symlinkPath = symlinkInfo.ContentsPath;
+
+                var newFile = new UnixSymbolicLinkInfo(destination);
+
+                if (isSameDir)
+                { // We're in the same dir, so we can preserve relative symlinks.
+                    newFile.CreateSymbolicLinkTo(symlinkInfo.ContentsPath);
+                }
+                else
+                {
+                    var fullPath = UnixPath.Combine(UnixPath.GetDirectoryName(source), symlinkPath);
+                    newFile.CreateSymbolicLinkTo(fullPath);
+                }
+
+                try
+                {
+                    // Finally remove the original symlink.
+                    symlinkInfo.Delete();
+                }
+                catch
+                {
+                    // Removing symlink failed, so rollback the new link and throw.
+                    newFile.Delete();
+                    throw;
+                }
+            }
+            else
+            {
+                base.MoveFileInternal(source, destination);
+            }
+        }
+
         public override bool TryCreateHardLink(string source, string destination)
         {
             try
             {
-                UnixFileSystemInfo.GetFileSystemEntry(source).CreateLink(destination);
+                var fileInfo = UnixFileSystemInfo.GetFileSystemEntry(source);
+
+                if (fileInfo.IsSymbolicLink) return false;
+
+                fileInfo.CreateLink(destination);
                 return true;
             }
             catch (Exception ex)