diff --git a/app/assets/javascripts/app/controllers/_ui_element/ticket_selector.coffee b/app/assets/javascripts/app/controllers/_ui_element/ticket_selector.coffee
index 8e40c64f5..344441b06 100644
--- a/app/assets/javascripts/app/controllers/_ui_element/ticket_selector.coffee
+++ b/app/assets/javascripts/app/controllers/_ui_element/ticket_selector.coffee
@@ -24,10 +24,23 @@ class App.UiElement.ticket_selector
       '^input$': ['contains', 'contains not']
       '^textarea$': ['contains', 'contains not']
 
+    if attribute.hasChanged
+      operators_type =
+        '^datetime$': ['before (absolute)', 'after (absolute)', 'before (relative)', 'within next (relative)', 'within last (relative)', 'after (relative)', 'has changed']
+        '^timestamp$': ['before (absolute)', 'after (absolute)', 'before (relative)', 'within next (relative)', 'within last (relative)', 'after (relative)', 'has changed']
+        'boolean$': ['is', 'is not', 'has changed']
+        '^input$': ['contains', 'contains not', 'has changed']
+        '^textarea$': ['contains', 'contains not', 'has changed']
+
     operators_name =
       '_id$': ['is', 'is not']
       '_ids$': ['is', 'is not']
 
+    if attribute.hasChanged
+      operators_name =
+        '_id$': ['is', 'is not', 'has changed']
+        '_ids$': ['is', 'is not', 'has changed']
+
     # merge config
     elements = {}
 
@@ -37,9 +50,10 @@ class App.UiElement.ticket_selector
         display: 'Action'
         tag: 'select'
         null: false
+        translate: true
         options:
-          create: 'Created'
-          update: 'Updated'
+          create: 'created'
+          update: 'updated'
         operator: ['is', 'is not']
 
     for groupKey, groupMeta of groups
@@ -226,21 +240,37 @@ class App.UiElement.ticket_selector
   @buildOperator: (elementFull, elementRow, groupAndAttribute, elements, meta, attribute) ->
     currentOperator = elementRow.find('.js-operator option:selected').attr('value')
 
-    if !meta.operator
-      meta.operator = currentOperator
-
     name = "#{attribute.name}::#{groupAndAttribute}::operator"
 
+    if !meta.operator && currentOperator
+      meta.operator = currentOperator
+
     selection = $("<select class=\"form-control\" name=\"#{name}\"></select>")
 
     attributeConfig = elements[groupAndAttribute]
     if attributeConfig.operator
+
+      # check if operator exists
+      operatorExists = false
+      for operator in attributeConfig.operator
+        if meta.operator is operator
+          operatorExists = true
+          break
+
+      if !operatorExists
+        for operator in attributeConfig.operator
+          meta.operator = operator
+          break
+
       for operator in attributeConfig.operator
         operatorName = App.i18n.translateInline(operator)
         selected = ''
-        if meta.operator is operator
-          selected = 'selected="selected"'
-        selection.append("<option value=\"#{operator}\" #{selected}>#{operatorName}</option>")
+        if !groupAndAttribute.match(/^ticket/) && operator is 'has changed'
+          # do nothing, only show "has changed" in ticket attributes
+        else
+          if meta.operator is operator
+            selected = 'selected="selected"'
+          selection.append("<option value=\"#{operator}\" #{selected}>#{operatorName}</option>")
       selection
 
     elementRow.find('.js-operator select').replaceWith(selection)
@@ -355,6 +385,11 @@ class App.UiElement.ticket_selector
       item = App.UiElement['time_range'].render(config, {})
 
     elementRow.find('.js-value').removeClass('hide').html(item)
+    if meta.operator is 'has changed'
+      elementRow.find('.js-value').addClass('hide')
+      elementRow.find('.js-preCondition').addClass('hide')
+    else
+      elementRow.find('.js-value').removeClass('hide')
 
   @humanText: (condition) ->
     none = App.i18n.translateContent('No filter.')
diff --git a/app/assets/javascripts/app/models/_application_model.coffee b/app/assets/javascripts/app/models/_application_model.coffee
index 507d524d5..7ccf21ea2 100644
--- a/app/assets/javascripts/app/models/_application_model.coffee
+++ b/app/assets/javascripts/app/models/_application_model.coffee
@@ -590,6 +590,10 @@ class App.Model extends Spine.Model
 
       [ array of objects ]
 
+    examples:
+
+      list = App.Model.search({sortBy:'updated_at', order:'DESC'})
+
   ###
 
   @search: (params) ->
diff --git a/app/assets/javascripts/app/models/trigger.coffee b/app/assets/javascripts/app/models/trigger.coffee
index 94f2d1d48..84d00dc7c 100644
--- a/app/assets/javascripts/app/models/trigger.coffee
+++ b/app/assets/javascripts/app/models/trigger.coffee
@@ -4,7 +4,7 @@ class App.Trigger extends App.Model
   @url: @apiPath + '/triggers'
   @configure_attributes = [
     { name: 'name',       display: 'Name',          tag: 'input',     type: 'text', limit: 100, null: false },
-    { name: 'condition',  display: 'Conditions for effected objects', tag: 'ticket_selector', null: false, preview: false, action: true },
+    { name: 'condition',  display: 'Conditions for effected objects', tag: 'ticket_selector', null: false, preview: false, action: true, hasChanged: true },
     { name: 'perform',    display: 'Execute changes on objects',      tag: 'ticket_perform_action', null: true, notification: true },
     { name: 'active',     display: 'Active',        tag: 'active',    default: true },
     { name: 'updated_at', display: 'Updated',       tag: 'datetime',  readonly: 1 },
diff --git a/app/models/ticket/subject.rb b/app/models/ticket/subject.rb
index 805d30bf3..a24c8c144 100644
--- a/app/models/ticket/subject.rb
+++ b/app/models/ticket/subject.rb
@@ -76,6 +76,8 @@ returns
       subject = subject[ 0, ticket_subject_size.to_i ] + '[...]'
     end
 
+    subject.gsub!(/^[[:space:]]+/, '')
+    subject.gsub!(/[[:space:]]+$/, '')
     subject
   end
 end
diff --git a/app/models/transaction/background_job.rb b/app/models/transaction/background_job.rb
index 838e9c839..a70c2e874 100644
--- a/app/models/transaction/background_job.rb
+++ b/app/models/transaction/background_job.rb
@@ -12,7 +12,8 @@ class Transaction::BackgroundJob
     changes: {
       'attribute1' => [before,now],
       'attribute2' => [before,now],
-    }
+    },
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
diff --git a/app/models/transaction/clearbit_enrichment.rb b/app/models/transaction/clearbit_enrichment.rb
index e3fcffae9..1ddb7a5e9 100644
--- a/app/models/transaction/clearbit_enrichment.rb
+++ b/app/models/transaction/clearbit_enrichment.rb
@@ -10,7 +10,8 @@ class Transaction::ClearbitEnrichment
     changes: {
       'attribute1' => [before, now],
       'attribute2' => [before, now],
-    }
+    },
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
diff --git a/app/models/transaction/cti_caller_id_detection.rb b/app/models/transaction/cti_caller_id_detection.rb
index 5b7e08974..692485dab 100644
--- a/app/models/transaction/cti_caller_id_detection.rb
+++ b/app/models/transaction/cti_caller_id_detection.rb
@@ -10,6 +10,7 @@ class Transaction::CtiCallerIdDetection
     object_id: 123,
     via_web: true,
     user_id: 123,
+    created_at: Time.zone.now,
   },
   {
     object: 'User',
@@ -20,6 +21,7 @@ class Transaction::CtiCallerIdDetection
       'attribute1' => [before, now],
       'attribute2' => [before, now],
     }
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
diff --git a/app/models/transaction/notification.rb b/app/models/transaction/notification.rb
index 4a980f9af..e7ee25062 100644
--- a/app/models/transaction/notification.rb
+++ b/app/models/transaction/notification.rb
@@ -11,7 +11,8 @@ class Transaction::Notification
     changes: {
       'attribute1' => [before, now],
       'attribute2' => [before, now],
-    }
+    },
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
diff --git a/app/models/transaction/signature_detection.rb b/app/models/transaction/signature_detection.rb
index f44a5a230..2e362b35f 100644
--- a/app/models/transaction/signature_detection.rb
+++ b/app/models/transaction/signature_detection.rb
@@ -12,7 +12,8 @@ class Transaction::SignatureDetection
     changes: {
       'attribute1' => [before, now],
       'attribute2' => [before, now],
-    }
+    },
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
diff --git a/app/models/transaction/slack.rb b/app/models/transaction/slack.rb
index 40e449b28..27e28ef47 100644
--- a/app/models/transaction/slack.rb
+++ b/app/models/transaction/slack.rb
@@ -8,6 +8,7 @@ backend = Transaction::Slack.new(
     type: 'create',
     object_id: 1,
     user_id: 123,
+    created_at: Time.zone.now,
 )
 backend.perform
 
@@ -19,7 +20,8 @@ backend.perform
     changes: {
       'attribute1' => [before, now],
       'attribute2' => [before, now],
-    }
+    },
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
diff --git a/app/models/transaction/trigger.rb b/app/models/transaction/trigger.rb
index 8dbee34f8..7b71ba22d 100644
--- a/app/models/transaction/trigger.rb
+++ b/app/models/transaction/trigger.rb
@@ -11,7 +11,8 @@ class Transaction::Trigger
     changes: {
       'attribute1' => [before, now],
       'attribute2' => [before, now],
-    }
+    },
+    created_at: Time.zone.now,
     user_id: 123,
   },
 =end
@@ -49,28 +50,30 @@ class Transaction::Trigger
         next if condition['ticket.action']['operator'] != 'is' && condition['ticket.action']['value'] == @item[:type]
         condition.delete('ticket.action')
       end
-=begin
+
       # check "has changed" options
-      has_changed = true
-      trigger.condition.each do |key, value|
+      has_changed_condition_exists = false
+      has_changed = false
+      condition.each do |key, value|
         next if !value
         next if !value['operator']
         next if !value['operator']['has changed']
+        has_changed_condition_exists = true
 
         # next if has changed? && !@item[:changes][attribute]
         (object_name, attribute) = key.split('.', 2)
 
         # remove condition item, because it has changed
         if @item[:changes][attribute]
-          #condition.delete(key)
+          has_changed = true
+          condition.delete(key)
           next
         end
-        has_changed = false
         break
-        #{"ticket.state_id"=>{"operator"=>"has changed"
       end
-      next if !has_changed
-=end
+
+      next if has_changed_condition_exists && !has_changed
+
       # check if selector is matching
       condition['ticket.id'] = {
         operator: 'is',
@@ -99,12 +102,16 @@ class Transaction::Trigger
       # check in min one attribute has changed
       if @item[:type] == 'update' && !article_selector
         match = false
-        trigger.condition.each do |key, _value|
-          (object_name, attribute) = key.split('.', 2)
-          next if object_name != 'ticket'
-          next if !@item[:changes][attribute]
+        if has_changed_condition_exists && has_changed
           match = true
-          break
+        else
+          trigger.condition.each do |key, _value|
+            (object_name, attribute) = key.split('.', 2)
+            next if object_name != 'ticket'
+            next if !@item[:changes][attribute]
+            match = true
+            break
+          end
         end
         next if !match
       end
diff --git a/test/unit/ticket_test.rb b/test/unit/ticket_test.rb
index 57f1c830a..27247b253 100644
--- a/test/unit/ticket_test.rb
+++ b/test/unit/ticket_test.rb
@@ -278,6 +278,8 @@ class TicketTest < ActiveSupport::TestCase
     assert_equal('subject test 1', ticket1.title)
     assert_equal("ABC subject test 1 [Ticket##{ticket1.number}]", ticket1.subject_build('ABC subject test 1'))
     assert_equal("RE: ABC subject test 1 [Ticket##{ticket1.number}]", ticket1.subject_build('ABC subject test 1', true))
+    assert_equal("RE: ABC subject test 1 [Ticket##{ticket1.number}]", ticket1.subject_build('  ABC subject test 1', true))
+    assert_equal("RE: ABC subject test 1 [Ticket##{ticket1.number}]", ticket1.subject_build('ABC subject test 1  ', true))
     ticket1.destroy
 
   end
diff --git a/test/unit/ticket_trigger_test.rb b/test/unit/ticket_trigger_test.rb
index 595ae77ba..6a08086d3 100644
--- a/test/unit/ticket_trigger_test.rb
+++ b/test/unit/ticket_trigger_test.rb
@@ -614,4 +614,320 @@ class TicketTriggerTest < ActiveSupport::TestCase
     Trigger.destroy_all
   end
 
+  test '4 has changed' do
+    roles = Role.where(name: 'Customer')
+    customer1 = User.create_or_update(
+      login: 'postmaster@example.com',
+      firstname: 'Notification',
+      lastname: 'Customer1',
+      email: 'postmaster@example.com',
+      password: 'customerpw',
+      active: true,
+      roles: roles,
+      updated_at: '2015-02-05 16:37:00',
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    customer2 = User.create_or_update(
+      login: 'ticket-has-changed-customer2@example.com',
+      firstname: 'Notification',
+      lastname: 'Customer2',
+      email: 'ticket-has-changed-customer2@example.com',
+      password: 'customerpw',
+      active: true,
+      organization_id: nil,
+      roles: roles,
+      updated_at: '2015-02-05 16:37:00',
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    roles = Role.where(name: 'Agent')
+    agent1 = User.create_or_update(
+      login: 'agent-has-changed@example.com',
+      firstname: 'Has Changed',
+      lastname: 'Agent1',
+      email: 'agent-has-changed@example.com',
+      password: 'agentpw',
+      active: true,
+      roles: roles,
+      updated_at: '2015-02-05 16:37:00',
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    trigger1 = Trigger.create_or_update(
+      name: 'owner update - to customer',
+      condition: {
+        'ticket.owner_id' => {
+          'operator' => 'has changed',
+          'pre_condition' => 'current_user.id',
+          'value' => '',
+          'value_completion' => '',
+        }
+      },
+      perform: {
+        'notification.email' => {
+          'body' => '<p>The owner of ticket (Ticket##{ticket.number}) has changed.<p>
+<br/>
+<p>To provide additional information, please reply to this email or click on the following link:
+<a href="#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}">#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}</a>
+</p>
+<br/>
+<p><i><a href="http://zammad.com">Zammad</a>, your customer support system</i></p>',
+          'recipient' => 'ticket_customer',
+          'subject' => 'Owner has changed (#{ticket.title})',
+        },
+      },
+      disable_notification: true,
+      active: true,
+      created_by_id: 1,
+      updated_by_id: 1,
+    )
+
+    # process mail without Precedence header
+    content = IO.binread('test/fixtures/ticket_trigger/mail1.box')
+    ticket_p, article_p, user_p, mail = Channel::EmailParser.new.process({}, content)
+
+    assert_equal('aaäöüßad asd', ticket_p.title)
+    assert_equal('Users', ticket_p.group.name)
+    assert_equal('new', ticket_p.state.name)
+    assert_equal(1, ticket_p.articles.count)
+    article_p = ticket_p.articles.last
+
+    Observer::Transaction.commit
+
+    ticket_p.owner = agent1
+    ticket_p.save
+    Observer::Transaction.commit
+    assert_equal('aaäöüßad asd', ticket_p.title, 'ticket_p.title verify')
+    assert_equal('Users', ticket_p.group.name, 'ticket_p.group verify')
+    assert_equal('new', ticket_p.state.name, 'ticket_p.state verify')
+    assert_equal('2 normal', ticket_p.priority.name, 'ticket_p.priority verify')
+    assert_equal(2, ticket_p.articles.count, 'ticket_p.articles verify')
+
+    p ticket_p.articles.last.inspect
+    article_p = ticket_p.articles.last
+    assert_match('Owner has changed', article_p.subject)
+    assert_match('Zammad <zammad@localhost>', article_p.from)
+    assert_match('martin@example.com', article_p.to)
+    assert_no_match('config\.', article_p.body)
+    assert_match('http://zammad.example.com', article_p.body)
+    assert_no_match('ticket.', article_p.body)
+    assert_match(ticket_p.number, article_p.body)
+    assert_equal('text/html', article_p.content_type)
+
+    trigger1 = Trigger.create_or_update(
+      name: 'owner update - to customer',
+      condition: {
+        'ticket.owner_id' => {
+          'operator' => 'has changed',
+          'pre_condition' => 'current_user.id',
+          'value' => '',
+          'value_completion' => '',
+        },
+        'ticket.priority_id' => {
+          'operator' => 'is',
+          'value' => Ticket::Priority.lookup(name: '3 high').id.to_s,
+        },
+      },
+      perform: {
+        'notification.email' => {
+          'body' => '<p>The owner of ticket (Ticket##{ticket.number}) has changed.<p>
+<br/>
+<p>To provide additional information, please reply to this email or click on the following link:
+<a href="#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}">#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}</a>
+</p>
+<br/>
+<p><i><a href="http://zammad.com">Zammad</a>, your customer support system</i></p>',
+          'recipient' => 'ticket_customer',
+          'subject' => 'Owner has changed (#{ticket.title})',
+        },
+      },
+      disable_notification: true,
+      active: true,
+      created_by_id: 1,
+      updated_by_id: 1,
+    )
+
+    # process mail without Precedence header
+    content = IO.binread('test/fixtures/ticket_trigger/mail1.box')
+    ticket_p, article_p, user_p, mail = Channel::EmailParser.new.process({}, content)
+
+    assert_equal('aaäöüßad asd', ticket_p.title)
+    assert_equal('Users', ticket_p.group.name)
+    assert_equal('new', ticket_p.state.name)
+    assert_equal(1, ticket_p.articles.count)
+    article_p = ticket_p.articles.last
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.priority = Ticket::Priority.lookup(name: '1 low')
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.priority = Ticket::Priority.lookup(name: '3 high')
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.owner = agent1
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal('aaäöüßad asd', ticket_p.title, 'ticket_p.title verify')
+    assert_equal('Users', ticket_p.group.name, 'ticket_p.group verify')
+    assert_equal('new', ticket_p.state.name, 'ticket_p.state verify')
+    assert_equal('3 high', ticket_p.priority.name, 'ticket_p.priority verify')
+    assert_equal(2, ticket_p.articles.count, 'ticket_p.articles verify')
+
+    p ticket_p.articles.last.inspect
+    article_p = ticket_p.articles.last
+    assert_match('Owner has changed', article_p.subject)
+    assert_match('Zammad <zammad@localhost>', article_p.from)
+    assert_match('martin@example.com', article_p.to)
+    assert_no_match('config\.', article_p.body)
+    assert_match('http://zammad.example.com', article_p.body)
+    assert_no_match('ticket.', article_p.body)
+    assert_match(ticket_p.number, article_p.body)
+    assert_equal('text/html', article_p.content_type)
+
+    # should trigger
+    trigger1 = Trigger.create_or_update(
+      name: 'owner update - to customer',
+      condition: {
+        'ticket.owner_id' => {
+          'operator' => 'has changed',
+          'pre_condition' => 'current_user.id',
+          'value' => '',
+          'value_completion' => '',
+        },
+        'ticket.priority_id' => {
+          'operator' => 'is',
+          'value' => Ticket::Priority.lookup(name: '3 high').id.to_s,
+        },
+        'ticket.action' => {
+          'operator' => 'is not',
+          'value' => 'create',
+        },
+      },
+      perform: {
+        'notification.email' => {
+          'body' => '<p>The owner of ticket (Ticket##{ticket.number}) has changed.<p>
+<br/>
+<p>To provide additional information, please reply to this email or click on the following link:
+<a href="#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}">#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}</a>
+</p>
+<br/>
+<p><i><a href="http://zammad.com">Zammad</a>, your customer support system</i></p>',
+          'recipient' => 'ticket_customer',
+          'subject' => 'Owner has changed (#{ticket.title})',
+        },
+      },
+      disable_notification: true,
+      active: true,
+      created_by_id: 1,
+      updated_by_id: 1,
+    )
+
+    # process mail without Precedence header
+    content = IO.binread('test/fixtures/ticket_trigger/mail1.box')
+    ticket_p, article_p, user_p, mail = Channel::EmailParser.new.process({}, content)
+
+    assert_equal('aaäöüßad asd', ticket_p.title)
+    assert_equal('Users', ticket_p.group.name)
+    assert_equal('new', ticket_p.state.name)
+    assert_equal(1, ticket_p.articles.count)
+    article_p = ticket_p.articles.last
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.priority = Ticket::Priority.lookup(name: '1 low')
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.priority = Ticket::Priority.lookup(name: '3 high')
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.owner = agent1
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal('aaäöüßad asd', ticket_p.title, 'ticket_p.title verify')
+    assert_equal('Users', ticket_p.group.name, 'ticket_p.group verify')
+    assert_equal('new', ticket_p.state.name, 'ticket_p.state verify')
+    assert_equal('3 high', ticket_p.priority.name, 'ticket_p.priority verify')
+    assert_equal(2, ticket_p.articles.count, 'ticket_p.articles verify')
+
+    p ticket_p.articles.last.inspect
+    article_p = ticket_p.articles.last
+    assert_match('Owner has changed', article_p.subject)
+    assert_match('Zammad <zammad@localhost>', article_p.from)
+    assert_match('martin@example.com', article_p.to)
+    assert_no_match('config\.', article_p.body)
+    assert_match('http://zammad.example.com', article_p.body)
+    assert_no_match('ticket.', article_p.body)
+    assert_match(ticket_p.number, article_p.body)
+    assert_equal('text/html', article_p.content_type)
+
+    # should not trigger
+    trigger1 = Trigger.create_or_update(
+      name: 'owner update - to customer',
+      condition: {
+        'ticket.owner_id' => {
+          'operator' => 'has changed',
+          'pre_condition' => 'current_user.id',
+          'value' => '',
+          'value_completion' => '',
+        },
+        'ticket.action' => {
+          'operator' => 'is',
+          'value' => 'create',
+        },
+      },
+      perform: {
+        'notification.email' => {
+          'body' => '<p>The owner of ticket (Ticket##{ticket.number}) has changed.<p>
+<br/>
+<p>To provide additional information, please reply to this email or click on the following link:
+<a href="#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}">#{config.http_type}://#{config.fqdn}/#ticket/zoom/#{ticket.id}</a>
+</p>
+<br/>
+<p><i><a href="http://zammad.com">Zammad</a>, your customer support system</i></p>',
+          'recipient' => 'ticket_customer',
+          'subject' => 'Owner has changed (#{ticket.title})',
+        },
+      },
+      disable_notification: true,
+      active: true,
+      created_by_id: 1,
+      updated_by_id: 1,
+    )
+
+    # process mail without Precedence header
+    content = IO.binread('test/fixtures/ticket_trigger/mail1.box')
+    ticket_p, article_p, user_p, mail = Channel::EmailParser.new.process({}, content)
+
+    assert_equal(1, ticket_p.articles.count)
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    ticket_p.owner = agent1
+    ticket_p.save
+
+    Observer::Transaction.commit
+    assert_equal(1, ticket_p.articles.count)
+
+    Trigger.destroy_all
+  end
+
 end