class Sprockets::Index

def find_asset(path, options = {})
  options[:bundle] = true unless options.key?(:bundle)
  if asset = @assets[cache_key_for(path, options)]
    asset
  elsif asset = super
    logical_path_cache_key = cache_key_for(path, options)
    full_path_cache_key    = cache_key_for(asset.pathname, options)
    # Cache on Index
    @assets[logical_path_cache_key] = @assets[full_path_cache_key] = asset
    # Push cache upstream to Environment
    @environment.instance_eval do
      @assets[logical_path_cache_key] = @assets[full_path_cache_key] = asset
    end
    asset
  end
end