#2426 refactor to use predetermined referer

app/logical/sources/strategies/base.rb

@@ -74,6 +74,11 @@ module Sources
         [image_url]
       end
 
+      # Should be set to a url for sites that prevent hotlinking, or left nil for sites that don't.
+      def fake_referer
+        nil
+      end
+
     protected
       def agent
         raise NotImplementedError

app/logical/sources/strategies/pixiv.rb

@@ -6,7 +6,7 @@ module Sources
   module Strategies
     class Pixiv < Base
       attr_reader :zip_url, :ugoira_frame_data, :ugoira_content_type
-      
+
       MONIKER   = '(?:[a-zA-Z0-9_-]+)'
       TIMESTAMP = '(?:[0-9]{4}/[0-9]{2}/[0-9]{2}/[0-9]{2}/[0-9]{2}/[0-9]{2})'
       EXT = "(?:jpg|jpeg|png|gif)"
@@ -35,6 +35,10 @@ module Sources
         @pixiv_moniker
       end
 
+      def fake_referer
+        "http://www.pixiv.net"
+      end
+
       def has_artist_commentary?
         @artist_commentary_desc.present?
       end