From 4ec64cf8507a67eb71e3014e5fd3a5e85f28d2c5 Mon Sep 17 00:00:00 2001
From: Martin Gruner <mg@zammad.com>
Date: Tue, 12 Apr 2022 07:59:10 +0200
Subject: [PATCH] Fixes: #3867 - parsing incoming mails breaks on this line
 "Reply-To: <>".

(cherry picked from commit e3e64f1087ff9904a0b99573ebd7e9a0e18f4629)
---
 .../channel/filter/reply_to_based_sender.rb   |  4 +-
 .../filter/reply_to_based_sender_spec.rb      | 66 +++++++++++++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)
 create mode 100644 spec/models/channel/filter/reply_to_based_sender_spec.rb

diff --git a/app/models/channel/filter/reply_to_based_sender.rb b/app/models/channel/filter/reply_to_based_sender.rb
index ecd206e24..b8904f34a 100644
--- a/app/models/channel/filter/reply_to_based_sender.rb
+++ b/app/models/channel/filter/reply_to_based_sender.rb
@@ -4,7 +4,9 @@ module Channel::Filter::ReplyToBasedSender
 
   def self.run(_channel, mail, _transaction_params)
 
-    reply_to = mail[:'reply-to']
+    return if mail[:'reply-to'].blank?
+
+    reply_to = mail[:'reply-to'].gsub('<>', '').strip
     return if reply_to.blank?
 
     setting = Setting.get('postmaster_sender_based_on_reply_to')
diff --git a/spec/models/channel/filter/reply_to_based_sender_spec.rb b/spec/models/channel/filter/reply_to_based_sender_spec.rb
new file mode 100644
index 000000000..0aae90550
--- /dev/null
+++ b/spec/models/channel/filter/reply_to_based_sender_spec.rb
@@ -0,0 +1,66 @@
+# Copyright (C) 2012-2022 Zammad Foundation, https://zammad-foundation.org/
+
+require 'rails_helper'
+
+RSpec.describe Channel::Filter::ReplyToBasedSender, type: :channel_filter do
+  describe '.run' do
+    let(:mail_hash) { Channel::EmailParser.new.parse(<<~RAW.chomp) }
+      From: daffy.duck@acme.corp
+      To: batman@marvell.com
+      Subject: Anvil
+      Reply-To: #{reply_to}
+
+      I can haz anvil!
+    RAW
+
+    before do
+      Setting.set('postmaster_sender_based_on_reply_to', 'as_sender_of_email')
+    end
+
+    context 'when empty reply-to' do
+      let(:reply_to) { '' }
+
+      it 'keeps from' do
+        expect { filter(mail_hash) }
+          .not_to change { mail_hash[:from] }
+      end
+    end
+
+    context 'when empty reply-to realname and invalid address' do
+      let(:reply_to) { '<>' }
+
+      it 'keeps from' do
+        expect { filter(mail_hash) }
+          .not_to change { mail_hash[:from] }
+      end
+    end
+
+    context 'when valid reply-to address' do
+      let(:reply_to) { '<bugs.bunny@acme.corp>' }
+
+      it 'sets from to reply-to address' do
+        expect { filter(mail_hash) }
+          .to change { mail_hash[:from] }.to('bugs.bunny@acme.corp')
+      end
+    end
+
+    context 'when valid reply-to realname and address' do
+      let(:reply_to) { 'Bugs Bunny <bugs.bunny@acme.corp>' }
+
+      it 'sets from to reply-to realname and address' do
+        expect { filter(mail_hash) }
+          .to change { mail_hash[:from] }.to('Bugs Bunny <bugs.bunny@acme.corp>')
+      end
+    end
+
+    context 'when valid reply-to realname and invalid address' do
+      let(:reply_to) { '"Bugs Bunny" <>' }
+
+      it 'sets from to reply-to realname' do
+        expect { filter(mail_hash) }
+          .to change { mail_hash[:from] }.to('"Bugs Bunny"')
+      end
+    end
+
+  end
+end