Fixes #3801 - Remote change of the group id does show it falsly as user change and not render the new value to the ticket.

app/assets/javascripts/app/controllers/ticket_zoom.coffee

@@ -641,6 +641,7 @@ class App.TicketZoom extends App.Controller
     # update changes in ui
     currentStore = @currentStore()
     modelDiff = @formDiff(currentParams, currentStore)
+    return if _.isEmpty(modelDiff)
 
     # set followup state if needed
     @setDefaultFollowUpState(modelDiff, currentStore)
@@ -735,6 +736,14 @@ class App.TicketZoom extends App.Controller
 
     # do not compare null or undefined value
     if currentStore.ticket
+
+      # make sure that the compared state is same in local storage and
+      # rendered html. Else we could have race conditions of data
+      # which is not rendered yet
+      renderedUpdatedAt = @el.find('.edit').attr('data-ticket-updated-at')
+      return if !renderedUpdatedAt
+      return if currentStore.ticket.updated_at.toString() isnt renderedUpdatedAt
+
       for key, value of currentStore.ticket
         if value is null || value is undefined
           currentStore.ticket[key] = ''

app/assets/javascripts/app/controllers/ticket_zoom/sidebar_ticket.coffee

@@ -29,9 +29,15 @@ class Edit extends App.Controller
       # for the new ticket + eventually changed task state
       @formMeta.core_workflow = undefined
 
-    if followUpPossible == 'new_ticket' && ticketState != 'closed' ||
-       followUpPossible != 'new_ticket' ||
-       @permissionCheck('admin') || @ticket.currentView() is 'agent'
+    editable = @ticket.editable()
+    if followUpPossible == 'new_ticket' && ticketState != 'closed' || followUpPossible != 'new_ticket' || @permissionCheck('admin') || @ticket.currentView() is 'agent'
+      editable = !editable
+
+    # reset updated_at for the sidbar because we render a new state
+    # it is used to compare the ticket with the rendered data later
+    # and needed to prevent race conditions
+    @el.removeAttr('data-ticket-updated-at')
+
     @controllerFormSidebarTicket = new App.ControllerForm(
       elReplace:      @el
       model:          { className: 'Ticket', configure_attributes: @formMeta.configure_attributes || App.Ticket.configure_attributes }
@@ -40,23 +46,7 @@ class Edit extends App.Controller
       filter:         @formMeta.filter
       formMeta:       @formMeta
       params:         defaults
-        isDisabled:     !@ticket.editable()
-        taskKey:        @taskKey
-        core_workflow: {
-          callbacks: [@markForm]
-        }
-        #bookmarkable:  true
-      )
-    else
-      @controllerFormSidebarTicket = new App.ControllerForm(
-        elReplace:      @el
-        model:          { className: 'Ticket', configure_attributes: @formMeta.configure_attributes || App.Ticket.configure_attributes }
-        screen:         'edit'
-        handlersConfig: handlers
-        filter:         @formMeta.filter
-        formMeta:       @formMeta
-        params:         defaults
-        isDisabled:     @ticket.editable()
+      isDisabled:     editable
       taskKey:        @taskKey
       core_workflow: {
         callbacks: [@markForm]
@@ -64,6 +54,8 @@ class Edit extends App.Controller
       #bookmarkable:  true
     )
 
+    # set updated_at for the sidbar because we render a new state
+    @el.attr('data-ticket-updated-at', defaults.updated_at)
     @markForm(true)
 
     return if @resetBind

spec/system/ticket/zoom_spec.rb

@@ -2149,6 +2149,13 @@ RSpec.describe 'Ticket zoom', type: :system do
       expect(page.find("select[name='priority_id']").value).to eq(high_prio.id.to_s)
     end
 
+    it 'does show up the new group (different case because it will also trigger a full rerender because of potential permission changes)' do
+      group = Group.find_by(name: 'some group1')
+      ticket.update(group: group)
+      wait(10, interval: 0.5).until { page.find("select[name='group_id']").value == group.id.to_s }
+      expect(page.find("select[name='group_id']").value).to eq(group.id.to_s)
+    end
+
     it 'does show up the new state and pending time' do
       pending_state = Ticket::State.find_by(name: 'pending reminder')
       ticket.update(state: pending_state, pending_time: 1.day.from_now)