Merge branch '18536_status_dropdown_label' into 'master'

Set button label when picking an option from status dropdown

## What does this MR do?
Fixes an issue with the status dropdown. It was not setting up the correct label after picking an option

## What are the relevant issue numbers?
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18536

## Screenshots (if relevant)

**Previous**

![status-select-previous](/uploads/7c6adbd6c5ba2660dc39a762d53d3b68/status-select-previous.gif)

**After**

![status-select](/uploads/91483efed8fbd63a79a01c9ca2154b74/status-select.gif)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- [ ] Tests
  - [ ] Added for this feature/bug
  - [x] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4771

app/assets/javascripts/gl_dropdown.js.coffee

@@ -462,7 +462,7 @@ class GitLabDropdown
 
       # Toggle the dropdown label
       if @options.toggleLabel
-        @updateLabel()
+        @updateLabel(selectedObject, el, @)
       else
         selectedObject
     else if el.hasClass(INDETERMINATE_CLASS)
@@ -489,7 +489,7 @@ class GitLabDropdown
 
       # Toggle the dropdown label
       if @options.toggleLabel
-        @updateLabel(selectedObject, el)
+        @updateLabel(selectedObject, el, @)
       if value?
         if !field.length and fieldName
           @addInput(fieldName, value)
@@ -588,8 +588,8 @@ class GitLabDropdown
       # Scroll the dropdown content up
       $dropdownContent.scrollTop(listItemTop - dropdownContentTop)
 
-  updateLabel: (selected = null, el = null) =>
-    $(@el).find(".dropdown-toggle-text").text @options.toggleLabel(selected, el)
+  updateLabel: (selected = null, el = null, instance = null) =>
+    $(@el).find(".dropdown-toggle-text").text @options.toggleLabel(selected, el, instance)
 
 $.fn.glDropdown = (opts) ->
   return @.each ->

app/assets/javascripts/issue_status_select.js.coffee

@@ -6,6 +6,13 @@ class @IssueStatusSelect
       $(el).glDropdown(
         selectable: true
         fieldName: fieldName
+        toggleLabel: (selected, el, instance) =>
+          label = 'Author'
+          $item = instance.dropdown.find('.is-active')
+          label = $item.text() if $item.length
+          label
+        clicked: (item, $el, e)->
+          e.preventDefault()
         id: (obj, el) ->
           $(el).data("id")
       )