Author: Jérémy Lal <kapouer@melix.org>
Bug-Debian: http://bugs.debian.org/570308

---
Engines plugin writes to /usr/share/redmine/public/plugin_assets
at runtime. This patch makes it write to a proper directory.

--- a/config/environment.rb
+++ b/config/environment.rb
@@ -35,6 +35,7 @@
 # Load Engine plugin if available
 begin
   require File.join(File.dirname(__FILE__), '../vendor/plugins/engines/boot')
+  Engines::public_directory = "#{ENV['RAILS_CACHE']}/plugin_assets"
 rescue LoadError
   # Not available
 end