Redmine

In projects_controller.rb, line 297:

    @issues_by_version = {}
    unless @selected_tracker_ids.empty?
      @versions.each do |version|
        issues = version.fixed_issues.visible.find(:all,
                                                   :include => [:project, :status, :tracker, :priority],
                                                   :conditions => {:tracker_id => @selected_tracker_ids, :project_id => project_ids},
                                                   :order => "#{Project.table_name}.lft, #{Tracker.table_name}.position, #{Issue.table_name}.id")
        @issues_by_version[version] = issues
      end
    end
    @versions.reject! {|version| !project_ids.include?(version.project_id) && @issues_by_version[version].empty?}

if @selected_tracker_ids.empty? is true, @issues_by_version will always be {} and @issues_by_version[version].empty? yields a NoMethodError.

Instead of empty?, blank? should be used. Patch is attached.