fix: ignore case when making hard links

ConvertTask.cs

@@ -8,7 +8,6 @@
 using Heliosphere.Util;
 using Newtonsoft.Json;
 using StrawberryShake;
-using Windows.Win32;
 
 namespace Heliosphere;
 
@@ -116,16 +115,18 @@ internal async Task Run() {
                     throw new SecurityException("path from mod was attempting to leave the files directory");
                 }
 
+                if (outputPath.Equals(existingPath, StringComparison.InvariantCultureIgnoreCase)) {
+                    continue;
+                }
+
                 if (File.Exists(outputPath)) {
                     continue;
                 }
 
                 var parent = PathHelper.GetParent(outputPath);
                 Directory.CreateDirectory(parent);
 
-                if (!PInvoke.CreateHardLink(@$"\\?\{outputPath}", @$"\\?\{existingPath}")) {
-                    throw new IOException($"failed to create hard link: {existingPath} -> {outputPath}");
-                }
+                FileHelper.CreateHardLink(existingPath, outputPath);
             }
 
             finished += 1;

DownloadTask.cs

@@ -18,7 +18,6 @@
 using Newtonsoft.Json.Linq;
 using Penumbra.Api.Enums;
 using StrawberryShake;
-using Windows.Win32;
 using ZstdSharp;
 
 namespace Heliosphere;
@@ -714,7 +713,7 @@ private static async Task DuplicateFile(string filesDir, IEnumerable<string> out
 
         async Task DuplicateInner(string dest) {
             dest = Path.Join(filesDir, dest);
-            if (path == dest) {
+            if (path.Equals(dest, StringComparison.InvariantCultureIgnoreCase)) {
                 return;
             }
 
@@ -729,9 +728,7 @@ async Task DuplicateInner(string dest) {
             var parent = PathHelper.GetParent(dest);
             Plugin.Resilience.Execute(() => Directory.CreateDirectory(parent));
 
-            if (!PInvoke.CreateHardLink(@$"\\?\{dest}", @$"\\?\{path}")) {
-                throw new IOException($"failed to create hard link {path} -> {dest}");
-            }
+            FileHelper.CreateHardLink(path, dest);
         }
     }
 

Util/FileHelper.cs

@@ -1,4 +1,6 @@
+using System.Runtime.InteropServices;
 using Heliosphere.Exceptions;
+using Windows.Win32;
 
 namespace Heliosphere.Util;
 
@@ -89,4 +91,22 @@ private static async Task<T> WrapAsync<T>(string path, Func<string, Task<T>> act
             throw new AlreadyInUseException(io, path, procs);
         }
     }
+
+    internal static void CreateHardLink(string source, string destination) {
+        const string prefix = @"\\?\";
+
+        var prefixedSource = source.StartsWith(prefix)
+            ? source
+            : prefix + source;
+        var prefixedDestination = destination.StartsWith(prefix)
+            ? destination
+            : prefix + destination;
+
+        if (PInvoke.CreateHardLink(prefixedDestination, prefixedSource)) {
+            return;
+        }
+
+        var error = Marshal.GetLastWin32Error();
+        throw new IOException($"Failed to create hard link (0x{error:X}): {source} -> {destination}");
+    }
 }