gitlabhq/app/views/compare/_form.html.haml

%div
  %p.slead
    Fill input field with commit id like
    %code.label_branch 4eedf23
    or branch/tag name like
    %code.label_branch master
    and press compare button for commits list, code diff.

  %br

  = form_tag project_compare_index_path(@project), method: :post do
    .clearfix
      = text_field_tag :from, params[:from], placeholder: "master", class: "xlarge"
      = "..."
      = text_field_tag :to, params[:to], placeholder: "aa8b4ef", class: "xlarge"
      - if params[:to] && params[:from]
        = link_to 'switch', {from: params[:to], to: params[:from]}, {class: 'commits-compare-switch has_tooltip', title: 'Switch base of comparison'}
    - if @refs_are_same
      .alert
        %span Refs are the same
    .actions
      = submit_tag "Compare", class: "btn primary wide commits-compare-btn"


 
:javascript
  $(function() {
    var availableTags = #{@project.ref_names.to_json};

    $("#from, #to").autocomplete({
      source: availableTags,
      minLength: 1
    });

    disableButtonIfEmptyField('#to', '.commits-compare-btn');
  });