#399

backend/app/models/post.rb

@@ -158,10 +158,8 @@ class Post < ApplicationRecord
   def attach_thumbnail_from_url! raw_url
     response = Preview::ThumbnailFetcher.fetch_image_response(raw_url)
     thumbnail.attach(
-        io: StringIO.new(response.body),
-        filename: remote_thumbnail_filename(response.url),
-        content_type: response.content_type)
-    resized_thumbnail!
+        self.class.resized_thumbnail_attachment(
+            StringIO.new(response.body)))
   rescue Preview::UrlSafety::UnsafeUrl,
          Preview::ThumbnailFetcher::GenerationFailed,
          Preview::HttpFetcher::FetchFailed,
@@ -173,15 +171,6 @@ class Post < ApplicationRecord
 
   private
 
-  def remote_thumbnail_filename url
-    filename = File.basename(URI.parse(url).path.to_s)
-    return filename if filename.present? && filename != '/'
-
-    'thumbnail'
-  rescue URI::InvalidURIError
-    'thumbnail'
-  end
-
   def validate_original_created_range
     f = parse_original_created_value(:original_created_from)
     b = parse_original_created_value(:original_created_before)