1 files changed, 10 insertions, 1 deletions

diff --git a/app/models/concerns/file_attachment.rb b/app/models/concerns/file_attachment.rb
index 613a6f0..e7a33c5 100644
--- a/app/models/concerns/file_attachment.rb
+++ b/app/models/concerns/file_attachment.rb
@@ -52,6 +52,14 @@ module FileAttachment
     build_upload_proxy
   end
 
+  def has_variant?(style)
+    upload_file_name.present? && File.exist?(file_path(style))
+  end
+
+  def previewable?
+    has_variant?(:medium)
+  end
+
   private
 
   def build_upload_proxy
@@ -106,7 +114,8 @@ module FileAttachment
   end
 
   def sanitize_filename(filename)
-    File.basename(filename).gsub(/[^\w\.\-]/, '_')
+    name = File.basename(filename).unicode_normalize(:nfc)
+    name.gsub(/(?u)[^\w\.\-]/, '_')
   end
 
   # Proxy object returned by asset.upload, providing the Paperclip-compatible