Fixes #3150 - Make channels trusted.

app/models/channel/filter/trusted.rb

@@ -6,7 +6,7 @@ module Channel::Filter::Trusted
   def self.run(channel, mail)
 
     # check if trust x-headers
-    if !channel[:trusted]
+    if !trusted(channel)
       mail.each_key do |key|
         next if !key.match?(/^x-zammad/i)
 
@@ -26,4 +26,11 @@ module Channel::Filter::Trusted
     end
 
   end
+
+  def self.trusted(channel)
+    return true if channel[:trusted]
+    return true if channel.instance_of?(Channel) && channel.options[:inbound][:trusted]
+
+    false
+  end
 end

spec/models/channel/email_parser_spec.rb

@@ -164,6 +164,43 @@ RSpec.describe Channel::EmailParser, type: :model do
           end
         end
       end
+
+      context 'when email contains x-headers' do
+        let(:raw_mail) { <<~RAW.chomp }
+          From: foo@bar.com
+          To: baz@qux.net
+          Subject: Foo
+          X-Zammad-Ticket-priority: 3 high
+
+          Lorem ipsum dolor
+        RAW
+
+        context 'when channel is not trusted' do
+          let(:channel) { create(:channel, options: { inbound: { trusted: false } }) }
+
+          it 'does not change the priority of the ticket (no channel)' do
+            described_class.new.process({}, raw_mail)
+
+            expect(Ticket.last.priority.name).to eq('2 normal')
+          end
+
+          it 'does not change the priority of the ticket (untrusted)' do
+            described_class.new.process(channel, raw_mail)
+
+            expect(Ticket.last.priority.name).to eq('2 normal')
+          end
+        end
+
+        context 'when channel is trusted' do
+          let(:channel) { create(:channel, options: { inbound: { trusted: true } }) }
+
+          it 'does not change the priority of the ticket' do
+            described_class.new.process(channel, raw_mail)
+
+            expect(Ticket.last.priority.name).to eq('3 high')
+          end
+        end
+      end
     end
 
     describe 'associating emails to existing tickets' do