Cap task to only precompile rails 3.1 assets if asset files have changed

deploy.rb

set :branch, "origin/#{ENV['BRANCH'] || "master"}"

namespace :assets do
  desc "Precompile rails 3.1 assets"
  task :precompile, :except => { :no_release => true } do
    asset_paths = "app/assets lib/assets vendor/assets"
    if !ENV['FORCE_PRECOMPILE'].nil? || capture("cd #{current_path}; git diff-tree --name-only -r #{deployed_revision} HEAD #{asset_paths} | wc -l").strip.to_i > 0
      deploy.precompile_assets
    else
      logger.info "Skipping asset pre-compilation because there were no asset changes"
    end
  end
end

namespace :deploy do
  desc "Update the deployed code."
  task :update_code, :except => { :no_release => true } do
    run("cat #{current_path}/REVISION") { |c,s,d| set(:deployed_revision, d[0,7]) }
    run("cd #{current_path}; git fetch origin; git reset --hard #{branch}; git submodule update --init;echo '#{branch}' > #{current_path}/BRANCH; git rev-parse #{branch} > #{current_path}/REVISION")
  end
end

Now that I actually get to review it, a question: Why are you overriding the update_code task? Couldn't you just use a before/after callback specifically for the git strategy?