gitlabhq/app/controllers/compare_controller.rb

class CompareController < ProjectResourceController
  # Authorize
  before_filter :authorize_read_project!
  before_filter :authorize_code_access!
  before_filter :require_non_empty_project

  def index
  end

  def show
    result = Commit.compare(project, params[:from], params[:to])

    @commits       = result[:commits]
    @commit        = result[:commit]
    @diffs         = result[:diffs]
    @refs_are_same = result[:same]
    @line_notes    = []

    @commits = CommitDecorator.decorate(@commits)
  end

  def create
    redirect_to project_compare_path(@project, params[:from], params[:to])
  end
end