Fixes #3667 - No possibility to enforce auto response if one of the blocking auto response mail header exists.

app/models/channel/filter/auto_response_check.rb

@@ -4,15 +4,18 @@ module Channel::Filter::AutoResponseCheck
 
   def self.run(_channel, mail, _transaction_params)
 
-    # if header is available, do not generate auto response
+    header_is_auto_response_exists = mail.key?(:'x-zammad-is-auto-response')
-    mail[ :'x-zammad-send-auto-response' ] = false
+    mail[ :'x-zammad-is-auto-response' ] = header_is_auto_response_exists ? ActiveModel::Type::Boolean.new.cast(mail[ :'x-zammad-is-auto-response' ]) : true
-    mail[ :'x-zammad-is-auto-response' ] = true
 
-    if !mail[ :'x-zammad-article-preferences' ]
+    header_send_auto_response_exists = mail.key?(:'x-zammad-send-auto-response')
-      mail[ :'x-zammad-article-preferences' ] = {}
+    mail[ :'x-zammad-send-auto-response' ] = header_send_auto_response_exists ? ActiveModel::Type::Boolean.new.cast(mail[ :'x-zammad-send-auto-response' ]) : !mail[ :'x-zammad-is-auto-response' ]
-    end
+
-    mail[ :'x-zammad-article-preferences' ]['send-auto-response'] = false
+    mail[ :'x-zammad-article-preferences' ] ||= {}
-    mail[ :'x-zammad-article-preferences' ]['is-auto-response'] = true
+    mail[ :'x-zammad-article-preferences' ]['send-auto-response'] = mail[ :'x-zammad-send-auto-response' ]
+    mail[ :'x-zammad-article-preferences' ]['is-auto-response'] = mail[ :'x-zammad-is-auto-response' ]
+
+    # Skip the auto response checks, if the header already exists.
+    return if header_is_auto_response_exists
 
     # do not send an auto response if one of the following headers exists
     return if mail[ :'list-unsubscribe' ] && mail[ :'list-unsubscribe' ] =~ %r{...}
@@ -28,10 +31,10 @@ module Channel::Filter::AutoResponseCheck
       return if message_id.match?(%r{@#{Regexp.quote(fqdn)}}i)
     end
 
-    mail[ :'x-zammad-send-auto-response' ] = true
+    mail[ :'x-zammad-send-auto-response' ] = true if !header_send_auto_response_exists
     mail[ :'x-zammad-is-auto-response' ] = false
 
-    mail[ :'x-zammad-article-preferences' ]['send-auto-response'] = true
+    mail[ :'x-zammad-article-preferences' ]['send-auto-response'] = mail[ :'x-zammad-send-auto-response' ]
     mail[ :'x-zammad-article-preferences' ]['is-auto-response'] = false
 
   end

spec/models/channel/filter/auto_response_check_spec.rb

@@ -0,0 +1,112 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+require 'rails_helper'
+
+RSpec.describe Channel::Filter::AutoResponseCheck, type: :channel_filter do
+  let(:mail) do
+    {
+      From: 'me@example.com'
+    }
+  end
+
+  shared_examples 'check auto response header' do |send_auto_response_state, is_auto_response_state|
+    let(:mail_auto_response) do
+      {
+        'x-zammad-send-auto-response':  send_auto_response_state,
+        'x-zammad-is-auto-response':    is_auto_response_state,
+        'x-zammad-article-preferences': {
+          'send-auto-response' => send_auto_response_state,
+          'is-auto-response'   => is_auto_response_state
+        }
+      }
+    end
+
+    it 'check filter result' do
+      filter(mail)
+      expect(mail).to match(a_hash_including(mail_auto_response))
+    end
+  end
+
+  context 'with no blocking response header' do
+    include_examples 'check auto response header', true, false
+  end
+
+  context 'with no blocking response header and x-zammad-send-auto-response:false' do
+    let(:mail) do
+      {
+        'x-zammad-send-auto-response': 'false'
+      }
+    end
+
+    include_examples 'check auto response header', false, false
+  end
+
+  context 'with blocking auto response header' do
+    context 'with header precedence:list' do
+      let(:mail) do
+        {
+          precedence: 'list'
+        }
+      end
+
+      include_examples 'check auto response header', false, true
+    end
+
+    context 'with header precedence:list and x-zammad-send-auto-response:true' do
+      let(:mail) do
+        {
+          precedence:                    'list',
+          'x-zammad-send-auto-response': 'true'
+        }
+      end
+
+      include_examples 'check auto response header', true, true
+    end
+
+    context 'with header precedence:list and x-zammad-send-auto-response:false' do
+      let(:mail) do
+        {
+          precedence:                    'list',
+          'x-zammad-send-auto-response': 'false'
+        }
+      end
+
+      include_examples 'check auto response header', false, true
+    end
+
+    context 'with header precedence:list and x-zammad-is-auto-response:false' do
+      let(:mail) do
+        {
+          precedence:                  'list',
+          'x-zammad-is-auto-response': 'false'
+        }
+      end
+
+      include_examples 'check auto response header', true, false
+    end
+
+    context 'with header precedence:list, x-zammad-is-auto-response:false and x-zammad-send-auto-response:false' do
+      let(:mail) do
+        {
+          precedence:                    'list',
+          'x-zammad-is-auto-response':   'false',
+          'x-zammad-send-auto-response': 'false'
+        }
+      end
+
+      include_examples 'check auto response header', false, false
+    end
+
+    context 'with header precedence:list, x-zammad-is-auto-response:true and x-zammad-send-auto-response:true' do
+      let(:mail) do
+        {
+          precedence:                    'list',
+          'x-zammad-is-auto-response':   'true',
+          'x-zammad-send-auto-response': 'true'
+        }
+      end
+
+      include_examples 'check auto response header', true, true
+    end
+  end
+end