Fixed issue #1733: Can't un-link i-doit Objects in a Ticket.

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

@@ -22,7 +22,12 @@ class SidebarIdoit extends App.Controller
       container: @el.closest('.content')
       callback: (objectIds, objectSelectorUi) =>
         if @ticket && @ticket.id
-          @updateTicket(@ticket.id, objectIds, =>
+
+          # add new objectIds to list of all @objectIds
+          # and transfer the complete list to the backend
+          @objectIds = @objectIds.concat(objectIds)
+
+          @updateTicket(@ticket.id, @objectIds, =>
             objectSelectorUi.close()
             @showObjectsContent(objectIds)
           )

app/controllers/integration/idoit_controller.rb

@@ -40,8 +40,7 @@ class Integration::IdoitController < ApplicationController
     ticket = Ticket.find(params[:ticket_id])
     access!(ticket, 'read')
     ticket.preferences[:idoit] ||= {}
-    ticket.preferences[:idoit][:object_ids] ||= []
-    ticket.preferences[:idoit][:object_ids].concat(params[:object_ids])
+    ticket.preferences[:idoit][:object_ids] = Array(params[:object_ids]).uniq
     ticket.save!
 
     render json: {