From 85cee64c73ab3de59d8253fa92c956fe78f50d18 Mon Sep 17 00:00:00 2001
From: Rolf Schmidt <rolf.schmidt@zammad.com>
Date: Mon, 13 Sep 2021 12:56:16 +0100
Subject: [PATCH] Fixes #3736 - scrollPageHeader disappears when answering via
 email.

---
 .../app/controllers/ticket_zoom.coffee        |  6 ++++--
 spec/system/ticket/zoom_spec.rb               | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/app/assets/javascripts/app/controllers/ticket_zoom.coffee b/app/assets/javascripts/app/controllers/ticket_zoom.coffee
index 4fd643f43..9a9bad539 100644
--- a/app/assets/javascripts/app/controllers/ticket_zoom.coffee
+++ b/app/assets/javascripts/app/controllers/ticket_zoom.coffee
@@ -454,8 +454,10 @@ class App.TicketZoom extends App.Controller
     App.TaskManager.touch(@taskKey)
 
     if !@renderDone
-      @renderDone = true
-      @autosaveLast = {}
+      @renderDone      = true
+      @autosaveLast    = {}
+      @scrollHeaderPos = undefined
+
       elLocal = $(App.view('ticket_zoom')
         ticket:         @ticket
         nav:            @nav
diff --git a/spec/system/ticket/zoom_spec.rb b/spec/system/ticket/zoom_spec.rb
index fefd6b484..84603a6e4 100644
--- a/spec/system/ticket/zoom_spec.rb
+++ b/spec/system/ticket/zoom_spec.rb
@@ -270,6 +270,25 @@ RSpec.describe 'Ticket zoom', type: :system do
         end
       end
     end
+
+    context 'scrollPageHeader disappears when answering via email #3736' do
+      let(:ticket) do
+        ticket = create(:ticket, group: Group.first)
+        create_list(:ticket_article, 15, ticket: ticket)
+        ticket
+      end
+
+      before do
+        visit "ticket/zoom/#{ticket.id}"
+      end
+
+      it 'does reset the scrollPageHeader on rerender of the ticket' do
+        select User.find_by(email: 'admin@example.com').fullname, from: 'Owner'
+        find('.js-textarea').send_keys('test 1234')
+        find('.js-submit').click
+        expect(page).to have_selector('div.scrollPageHeader .js-ticketTitleContainer')
+      end
+    end
   end
 
   describe 'delete article', authenticated_as: :authenticate do