consider disabled fieldset for disabled state (#2718)

* consider disabled fieldset for disabled state

fixes #2389

coffee/chosen.jquery.coffee

@@ -115,16 +115,18 @@ class Chosen extends AbstractChosen
     @form_field_jq.show()
 
   search_field_disabled: ->
-    @is_disabled = @form_field_jq[0].disabled
-    if(@is_disabled)
-      @container.addClass 'chosen-disabled'
-      @search_field[0].disabled = true
-      @selected_item.unbind "focus.chosen", @activate_action if !@is_multiple
+    @is_disabled = @form_field.disabled || @form_field_jq.parents('fieldset').is(':disabled')
+
+    @container.toggleClass 'chosen-disabled', @is_disabled
+    @search_field[0].disabled = @is_disabled
+
+    unless @is_multiple
+      @selected_item.unbind 'focus.chosen', this.activate_field
+
+    if @is_disabled
       this.close_field()
-    else
-      @container.removeClass 'chosen-disabled'
-      @search_field[0].disabled = false
-      @selected_item.bind "focus.chosen", @activate_action if !@is_multiple
+    else unless @is_multiple
+      @selected_item.bind 'focus.chosen', this.activate_field
 
   container_mousedown: (evt) ->
     return if @is_disabled

coffee/chosen.proto.coffee

@@ -110,16 +110,22 @@ class @Chosen extends AbstractChosen
     @form_field.show()
 
   search_field_disabled: ->
-    @is_disabled = @form_field.disabled
-    if(@is_disabled)
+    @is_disabled = @form_field.disabled || @form_field.up('fieldset')?.disabled || false
+
+    if @is_disabled
       @container.addClassName 'chosen-disabled'
-      @search_field.disabled = true
-      @selected_item.stopObserving "focus", @activate_action if !@is_multiple
-      this.close_field()
     else
       @container.removeClassName 'chosen-disabled'
-      @search_field.disabled = false
-      @selected_item.observe "focus", @activate_action if !@is_multiple
+
+    @search_field.disabled = @is_disabled
+
+    unless @is_multiple
+      @selected_item.stopObserving 'focus', this.activate_field
+
+    if @is_disabled
+      this.close_field()
+    else unless @is_multiple
+      @selected_item.observe 'focus', this.activate_field
 
   container_mousedown: (evt) ->
     return if @is_disabled

spec/jquery/basic.spec.coffee

@@ -64,3 +64,24 @@ describe "Basic setup", ->
       select.chosen()
       placeholder = div.find(".chosen-single > span")
       expect(placeholder.text()).toBe("<None>")
+
+  describe "disabled fieldset", ->
+
+    it "should render as disabled", ->
+      tmpl = "
+        <fieldset disabled>
+          <select data-placeholder='Choose a Country...'>
+            <option value=''></option>
+            <option value='United States'>United States</option>
+            <option value='United Kingdom'>United Kingdom</option>
+            <option value='Afghanistan'>Afghanistan</option>
+          </select>
+        </fieldset>
+      "
+      div = $("<div>").html(tmpl)
+      select = div.find("select")
+      expect(select.size()).toBe(1)
+      select.chosen()
+
+      container = div.find(".chosen-container")
+      expect(container.hasClass("chosen-disabled")).toBe true

spec/proto/basic.spec.coffee

@@ -75,3 +75,26 @@ describe "Basic setup", ->
 
       placeholder = div.down(".chosen-single > span")
       expect(placeholder.innerText).toBe("<None>")
+
+  describe "disabled fieldset", ->
+
+    it "should render as disabled", ->
+      tmpl = "
+        <fieldset disabled>
+          <select data-placeholder='Choose a Country...'>
+            <option value=''></option>
+            <option value='United States'>United States</option>
+            <option value='United Kingdom'>United Kingdom</option>
+            <option value='Afghanistan'>Afghanistan</option>
+          </select>
+        </fieldset>
+      "
+      div = new Element("div")
+      document.body.insert(div)
+      div.update(tmpl)
+      select = div.down("select")
+      expect(select).toBeDefined()
+      new Chosen(select)
+
+      container = div.down(".chosen-container")
+      expect(container.hasClassName("chosen-disabled")).toBe true