Add "Check out branch" button to the MR page.

CHANGELOG

@@ -43,6 +43,9 @@ v 7.14.0 (unreleased)
   - Fetch code from forks to refs/merge-requests/:id/head when merge request created
   - Remove satellites
   - Remove comments and email addresses when publicly exposing ssh keys (Zeger-Jan van de Weg)
+  - Improve MR merge widget text and UI consistency.
+  - Improve text in MR "How To Merge" modal.
+  - Add "Check out branch" button to the MR page.
 
 v 7.13.3
   - Fix bug causing Bitbucket importer to crash when OAuth application had been removed.

app/assets/stylesheets/pages/merge_requests.scss

@@ -179,3 +179,7 @@
 .merge-request-form .select2-container {
   width: 250px !important;
 }
+
+.mr-source-target {
+  line-height: 31px;
+}

app/views/projects/merge_requests/_show.html.haml

@@ -5,19 +5,25 @@
     %hr
     = render "projects/merge_requests/show/mr_box"
     %hr
-    .append-bottom-20
+    .append-bottom-20.mr-source-target
       - if @merge_request.open?
-        .btn-group.btn-group-sm.pull-right
-          %a.btn.btn-sm.dropdown-toggle{ data: {toggle: :dropdown} }
-            = icon('download')
-            Download as
-            %span.caret
-          %ul.dropdown-menu
-            %li= link_to "Email Patches", merge_request_path(@merge_request, format: :patch)
-            %li= link_to "Plain Diff",    merge_request_path(@merge_request, format: :diff)
+        .pull-right
+          - if @merge_request.source_branch_exists?
+            = link_to "#modal_merge_info", class: "btn btn-sm", "data-toggle" => "modal" do
+              = icon('cloud-download fw')
+              Check out branch
+
+          %span.dropdown
+            %a.btn.btn-sm.dropdown-toggle{ data: {toggle: :dropdown} }
+              = icon('download')
+              Download as
+              %span.caret
+            %ul.dropdown-menu
+              %li= link_to "Email Patches", merge_request_path(@merge_request, format: :patch)
+              %li= link_to "Plain Diff",    merge_request_path(@merge_request, format: :diff)
       .light
         %div
-          %span From
+          %span Request to merge
           %span.label-branch #{source_branch_with_namespace(@merge_request)}
           %span into
           %span.label-branch #{@merge_request.target_branch}