#399

backend/app/services/preview/thumbnail_fetcher.rb

@@ -32,7 +32,7 @@ module Preview
     def self.fetch_image_response(raw_url)
       uri, = UrlSafety.validate(raw_url)
       response = HttpFetcher.fetch(uri.to_s)
-      unless allowed_remote_image_content_type?(response.content_type)
+      unless allowed_remote_image_content_type?(response.content_type) || Post.svg_document_bytes?(response.body)
         raise GenerationFailed, 'サムネール画像が見つかりませんでした．'
       end