9 files changed, 126 insertions, 12 deletions

diff --git a/app/assets/javascripts/dispatcher.js b/app/assets/javascripts/dispatcher.js
index 7e469153106..b87c57c38fe 100644
--- a/app/assets/javascripts/dispatcher.js
+++ b/app/assets/javascripts/dispatcher.js
@@ -50,6 +50,7 @@ import UserCallout from './user_callout';
 import { ProtectedTagCreate, ProtectedTagEditList } from './protected_tags';
 import ShortcutsWiki from './shortcuts_wiki';
 import BlobViewer from './blob/viewer/index';
+import AutoWidthDropdownSelect from './issuable/auto_width_dropdown_select';
 
 const ShortcutsBlob = require('./shortcuts_blob');
 
@@ -198,6 +199,7 @@ const ShortcutsBlob = require('./shortcuts_blob');
           new LabelsSelect();
           new MilestoneSelect();
           new gl.IssuableTemplateSelectors();
+          new AutoWidthDropdownSelect($('.js-target-branch-select')).init();
           break;
         case 'projects:tags:new':
           new ZenMode();
diff --git a/app/assets/javascripts/issuable/auto_width_dropdown_select.js b/app/assets/javascripts/issuable/auto_width_dropdown_select.js
new file mode 100644
index 00000000000..2203a56315e
--- /dev/null
+++ b/app/assets/javascripts/issuable/auto_width_dropdown_select.js
@@ -0,0 +1,38 @@
+let instanceCount = 0;
+
+class AutoWidthDropdownSelect {
+  constructor(selectElement) {
+    this.$selectElement = $(selectElement);
+    this.dropdownClass = `js-auto-width-select-dropdown-${instanceCount}`;
+    instanceCount += 1;
+  }
+
+  init() {
+    const dropdownClass = this.dropdownClass;
+    this.$selectElement.select2({
+      dropdownCssClass: dropdownClass,
+      dropdownCss() {
+        let resultantWidth = 'auto';
+        const $dropdown = $(`.${dropdownClass}`);
+
+        // We have to look at the parent because
+        // `offsetParent` on a `display: none;` is `null`
+        const offsetParentWidth = $(this).parent().offsetParent().width();
+        // Reset any width to let it naturally flow
+        $dropdown.css('width', 'auto');
+        if ($dropdown.outerWidth(false) > offsetParentWidth) {
+          resultantWidth = offsetParentWidth;
+        }
+
+        return {
+          width: resultantWidth,
+          maxWidth: offsetParentWidth,
+        };
+      },
+    });
+
+    return this;
+  }
+}
+
+export default AutoWidthDropdownSelect;
diff --git a/app/assets/javascripts/new_branch_form.js b/app/assets/javascripts/new_branch_form.js
index 5828f460a23..67046d52a65 100644
--- a/app/assets/javascripts/new_branch_form.js
+++ b/app/assets/javascripts/new_branch_form.js
@@ -34,6 +34,7 @@
         filterByText: true,
         remote: false,
         fieldName: $branchSelect.data('field-name'),
+        filterInput: 'input[type="search"]',
         selectable: true,
         isSelectable: function(branch, $el) {
           return !$el.hasClass('is-active');
@@ -50,6 +51,21 @@
           }
         }
       });
+
+      const $dropdownContainer = $branchSelect.closest('.dropdown');
+      const $fieldInput = $(`input[name="${$branchSelect.data('field-name')}"]`, $dropdownContainer);
+      const $filterInput = $('input[type="search"]', $dropdownContainer);
+
+      $filterInput.on('keyup', (e) => {
+        const keyCode = e.keyCode || e.which;
+        if (keyCode !== 13) return;
+
+        const text = $filterInput.val();
+        $fieldInput.val(text);
+        $('.dropdown-toggle-text', $branchSelect).text(text);
+
+        $dropdownContainer.removeClass('open');
+      });
     };
 
     NewBranchForm.prototype.setupRestrictions = function() {
diff --git a/app/assets/stylesheets/pages/merge_requests.scss b/app/assets/stylesheets/pages/merge_requests.scss
index bca62b7fc31..72660113e3c 100644
--- a/app/assets/stylesheets/pages/merge_requests.scss
+++ b/app/assets/stylesheets/pages/merge_requests.scss
@@ -482,6 +482,10 @@
   }
 }
 
+.target-branch-select-dropdown-container {
+  position: relative;
+}
+
 .assign-to-me-link {
   padding-left: 12px;
   white-space: nowrap;
diff --git a/app/views/projects/branches/new.html.haml b/app/views/projects/branches/new.html.haml
index d3c3e40d518..796ecdfd014 100644
--- a/app/views/projects/branches/new.html.haml
+++ b/app/views/projects/branches/new.html.haml
@@ -1,4 +1,5 @@
 - page_title "New Branch"
+- default_ref = params[:ref] || @project.default_branch
 
 - if @error
   .alert.alert-danger
@@ -16,12 +17,11 @@
       .help-block.text-danger.js-branch-name-error
   .form-group
     = label_tag :ref, 'Create from', class: 'control-label'
-    .col-sm-10
-      = hidden_field_tag :ref, params[:ref] || @project.default_branch
-      = dropdown_tag(params[:ref] || @project.default_branch,
-                     options: { toggle_class: 'js-branch-select wide',
-                                filter: true, dropdown_class: "dropdown-menu-selectable", placeholder: "Search branches",
-                                data: { selected: params[:ref] || @project.default_branch, field_name: 'ref' } })
+    .col-sm-10.dropdown.create-from
+      = hidden_field_tag :ref, default_ref
+      = button_tag type: 'button', title: default_ref, class: 'dropdown-toggle form-control js-branch-select', required: true, data: { toggle: 'dropdown', selected: default_ref, field_name: 'ref' } do
+        .text-left.dropdown-toggle-text= default_ref
+      = render 'shared/ref_dropdown', dropdown_class: 'wide'
       .help-block Existing branch name, tag, or commit SHA
   .form-actions
     = button_tag 'Create branch', class: 'btn btn-create', tabindex: 3
diff --git a/app/views/projects/compare/_form.html.haml b/app/views/projects/compare/_form.html.haml
index 0f080b6acee..1f4c9fac54c 100644
--- a/app/views/projects/compare/_form.html.haml
+++ b/app/views/projects/compare/_form.html.haml
@@ -9,7 +9,7 @@
         = hidden_field_tag :from, params[:from]
         = button_tag type: 'button', title: params[:from], class: "form-control compare-dropdown-toggle js-compare-dropdown has-tooltip", required: true, data: { refs_url: refs_namespace_project_path(@project.namespace, @project), toggle: "dropdown", target: ".js-compare-from-dropdown", selected: params[:from], field_name: :from } do
           .dropdown-toggle-text.str-truncated= params[:from] || 'Select branch/tag'
-      = render "ref_dropdown"
+      = render 'shared/ref_dropdown'
     .compare-ellipsis.inline ...
     .form-group.dropdown.compare-form-group.to.js-compare-to-dropdown
       .input-group.inline-input-group
@@ -17,7 +17,7 @@
         = hidden_field_tag :to, params[:to]
         = button_tag type: 'button', title: params[:to], class: "form-control compare-dropdown-toggle js-compare-dropdown has-tooltip", required: true, data: { refs_url: refs_namespace_project_path(@project.namespace, @project), toggle: "dropdown", target: ".js-compare-to-dropdown", selected: params[:to], field_name: :to } do
           .dropdown-toggle-text.str-truncated= params[:to] || 'Select branch/tag'
-      = render "ref_dropdown"
+      = render 'shared/ref_dropdown'
      
     = button_tag "Compare", class: "btn btn-create commits-compare-btn"
     - if @merge_request.present?
diff --git a/app/views/projects/compare/_ref_dropdown.html.haml b/app/views/shared/_ref_dropdown.html.haml
index 05fb37cdc0f..96f68c80c48 100644
--- a/app/views/projects/compare/_ref_dropdown.html.haml
+++ b/app/views/shared/_ref_dropdown.html.haml
@@ -1,4 +1,6 @@
-.dropdown-menu.dropdown-menu-selectable
+- dropdown_class = local_assigns.fetch(:dropdown_class, '')
+
+.dropdown-menu.dropdown-menu-selectable{ class: dropdown_class }
   = dropdown_title "Select Git revision"
   = dropdown_filter "Filter by Git revision"
   = dropdown_content
diff --git a/app/views/shared/issuable/form/_branch_chooser.html.haml b/app/views/shared/issuable/form/_branch_chooser.html.haml
index 2793e7bcff4..f57b4d899ce 100644
--- a/app/views/shared/issuable/form/_branch_chooser.html.haml
+++ b/app/views/shared/issuable/form/_branch_chooser.html.haml
@@ -10,12 +10,16 @@
     = form.label :source_branch, class: 'control-label'
     .col-sm-10
       .issuable-form-select-holder
-        = form.select(:source_branch, [issuable.source_branch], {}, { class: 'source_branch select2 span2', disabled: true })
+        = form.select(:source_branch, [issuable.source_branch], {}, { class: 'source_branch select2', disabled: true })
 .form-group
   = form.label :target_branch, class: 'control-label'
-  .col-sm-10
+  .col-sm-10.target-branch-select-dropdown-container
     .issuable-form-select-holder
-      = form.select(:target_branch, issuable.target_branches, { include_blank: true }, { class: 'target_branch select2 span2', disabled: issuable.new_record?, data: { placeholder: "Select branch" }})
+      = form.select(:target_branch, issuable.target_branches,
+        { include_blank: true },
+        { class: 'target_branch js-target-branch-select',
+          disabled: issuable.new_record?,
+          data: { placeholder: "Select branch" }})
     - if issuable.new_record?
        
       = link_to 'Change branches', mr_change_branches_path(issuable)
diff --git a/spec/features/projects/branches/new_branch_ref_dropdown_spec.rb b/spec/features/projects/branches/new_branch_ref_dropdown_spec.rb
new file mode 100644
index 00000000000..cfc782c98ad
--- /dev/null
+++ b/spec/features/projects/branches/new_branch_ref_dropdown_spec.rb
@@ -0,0 +1,48 @@
+require 'spec_helper'
+
+describe 'New Branch Ref Dropdown', :js, :feature do
+  let(:user) { create(:user) }
+  let(:project) { create(:project, :public) }
+  let(:toggle) { find('.create-from .dropdown-toggle') }
+
+  before do
+    project.add_master(user)
+
+    login_as(user)
+    visit new_namespace_project_branch_path(project.namespace, project)
+  end
+
+  it 'filters a list of branches and tags' do
+    toggle.click
+
+    filter_by('v1.0.0')
+
+    expect(items_count).to be(1)
+
+    filter_by('video')
+
+    expect(items_count).to be(1)
+
+    find('.create-from .dropdown-content li').click
+
+    expect(toggle).to have_content 'video'
+  end
+
+  it 'accepts a manually entered commit SHA' do
+    toggle.click
+
+    filter_by('somecommitsha')
+
+    find('.create-from input[type=search]').send_keys(:enter)
+
+    expect(toggle).to have_content 'somecommitsha'
+  end
+
+  def items_count
+    all('.create-from .dropdown-content li').length
+  end
+
+  def filter_by(filter_text)
+    fill_in 'Filter by Git revision', with: filter_text
+  end
+end