Fixes #4118 - Single tree select no longer allows displaying child values.

app/assets/javascripts/app/lib/app_post/searchable_select.coffee

@@ -1,22 +1,23 @@
 class App.SearchableSelect extends Spine.Controller
 
   events:
-    'input .js-input':                      'onInput'
-    'blur .js-input':                       'onBlur'
-    'focus .js-input':                      'onFocus'
-    'focus .js-shadow':                     'onShadowFocus'
-    'change .js-shadow':                    'onShadowChange'
-    'click .js-option':                     'selectItem'
-    'click .searchableSelect-option-text':  'selectItem'
-    'click .searchableSelect-option-arrow': 'navigateIn'
-    'click .js-back':                       'navigateOut'
-    'mouseenter .js-option':                'highlightItem'
-    'mouseenter .js-enter':                 'highlightItem'
-    'mouseenter .js-back':                  'highlightItem'
-    'shown.bs.dropdown':                    'onDropdownShown'
-    'hidden.bs.dropdown':                   'onDropdownHidden'
-    'keyup .js-input':                      'onKeyUp'
-    'click .js-remove':                     'removeThisToken'
+    'input .js-input':                                'onInput'
+    'blur .js-input':                                 'onBlur'
+    'focus .js-input':                                'onFocus'
+    'focus .js-shadow':                               'onShadowFocus'
+    'change .js-shadow':                              'onShadowChange'
+    'click .js-option':                               'selectItem'
+    'click .js-option .searchableSelect-option-text': 'selectItem'
+    'click .js-enter .searchableSelect-option-text':  'navigateInOrSelectItem'
+    'click .searchableSelect-option-arrow':           'navigateIn'
+    'click .js-back':                                 'navigateOut'
+    'mouseenter .js-option':                          'highlightItem'
+    'mouseenter .js-enter':                           'highlightItem'
+    'mouseenter .js-back':                            'highlightItem'
+    'shown.bs.dropdown':                              'onDropdownShown'
+    'hidden.bs.dropdown':                             'onDropdownHidden'
+    'keyup .js-input':                                'onKeyUp'
+    'click .js-remove':                               'removeThisToken'
 
   elements:
     '.js-dropdown':               'dropdown'
@@ -288,6 +289,10 @@ class App.SearchableSelect extends Spine.Controller
     @input.val value
     @shadowInput.val key
 
+  navigateInOrSelectItem: (event) ->
+    return @selectItem(event) if @attribute.multiple
+    return @navigateIn(event)
+
   selectItem: (event) ->
     currentText = $(event.target).text().trim()
     return if !currentText
@@ -300,6 +305,8 @@ class App.SearchableSelect extends Spine.Controller
 
   navigateIn: (event) ->
     event.stopPropagation()
+    if !@attribute.multiple
+      @selectItem(event)
     @navigateDepth(1)
 
   navigateOut: (event) ->
@@ -512,8 +519,14 @@ class App.SearchableSelect extends Spine.Controller
 
   addValueToShadowInput: (currentText, dataId) ->
     @input.val('')
-    return if @shadowInput.val().includes("#{dataId}") if @shadowInput.val() # cast dataId to string before check
-    @currentData = {name: currentText, value: dataId}
+
+    if @attribute.multiple
+      return if @shadowInput.val().includes("#{dataId}") if @shadowInput.val() # cast dataId to string before check
+      @currentData = {name: currentText, value: dataId}
+    else
+      @currentData = {name: currentText, value: dataId}
+      return if @shadowInput.val().includes("#{dataId}") if @shadowInput.val() # cast dataId to string before check
+
     @shadowInput.append($('<option/>').attr('selected', true).attr('value', @currentData.value).text(@currentData.name))
     @onShadowChange()