Add another check for directory traversal

Use Path.GetFullPath to get the absolute path after translating
path separators and '.', '..' to ensure the path starts with the
expected base directory.

COM3D2.MeidoPhotoStudio.Plugin/MeidoPhotoStudio/Constants.cs

@@ -126,7 +126,7 @@ namespace COM3D2.MeidoPhotoStudio.Plugin
 
             if (File.Exists($"{fullPath}.anm")) fullPath += $"_{DateTime.Now:yyyyMMddHHmmss}";
 
-            fullPath += ".anm";
+            fullPath = Path.GetFullPath($"{fullPath}.anm");
 
             if (!fullPath.StartsWith(Constants.customPosePath))
             {
@@ -173,7 +173,7 @@ namespace COM3D2.MeidoPhotoStudio.Plugin
 
             if (File.Exists($"{fullPath}.xml")) fullPath += $"_{DateTime.Now:yyyyMMddHHmmss}";
 
-            fullPath += ".xml";
+            fullPath = Path.GetFullPath($"{fullPath}.xml");
 
             if (!fullPath.StartsWith(Constants.customHandPath))
             {