From 36b2d5b4d025291ac8ccc90ca662ccb1337aa9b4 Mon Sep 17 00:00:00 2001
From: Marius BALTEANU <marius.balteanu@zitec.com>
Date: Sat, 4 Sep 2021 14:20:28 +0300
Subject: [PATCH] Add setting in admin to control the hardbreaks behaviour for
 CommonMark (#32424).


diff --git a/app/views/settings/_general.html.erb b/app/views/settings/_general.html.erb
index 23abdb3f5..937b42322 100644
--- a/app/views/settings/_general.html.erb
+++ b/app/views/settings/_general.html.erb
@@ -19,7 +19,13 @@
 
 <p><%= setting_select :protocol, [['HTTP', 'http'], ['HTTPS', 'https']] %></p>
 
-<p><%= setting_select :text_formatting, Redmine::WikiFormatting.formats_for_select, :blank => :label_none %></p>
+<p>
+  <%= setting_select :text_formatting, Redmine::WikiFormatting.formats_for_select, :blank => :label_none %>
+  <label id="common_mark_settings" class="block <%= "hidden" unless Setting.text_formatting == "common_mark" %>">
+    <%= setting_check_box :text_formatting_common_mark_hardbreaks, label: false %>
+    <%= l(:setting_text_formatting_common_mark_hardbreaks) %>
+  </label>
+</p>
 
 <p><%= setting_check_box :cache_formatted_text %></p>
 
@@ -32,3 +38,15 @@
 
 <%= submit_tag l(:button_save) %>
 <% end %>
+
+<%= javascript_tag do %>
+  $('#settings_text_formatting').on('change', function(e){
+    const formatter = e.target.value;
+    const settings = document.getElementById("common_mark_settings");
+    if (formatter == "common_mark") {
+      settings.classList.remove('hidden');
+    } else {
+      settings.classList.add('hidden');
+    }
+  });
+<% end %>
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 952138bf4..ac759d250 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -510,6 +510,7 @@ en:
   setting_project_list_defaults: Projects list defaults
   setting_twofa: Two-factor authentication
   setting_default_issue_query: Default Query
+  setting_text_formatting_common_mark_hardbreaks: "Use regular line breaks (\\n) as hardbreaks"
 
   permission_add_project: Create project
   permission_add_subprojects: Create subprojects
diff --git a/config/settings.yml b/config/settings.yml
index 64209bdfd..f36a72236 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -96,6 +96,8 @@ plain_text_mail:
   default: 0
 text_formatting:
   default: textile
+text_formatting_common_mark_hardbreaks:
+  default: 1
 cache_formatted_text:
   default: 0
 wiki_compression:
diff --git a/lib/redmine/wiki_formatting/common_mark/formatter.rb b/lib/redmine/wiki_formatting/common_mark/formatter.rb
index 6a9c95c8e..44e4de8f0 100644
--- a/lib/redmine/wiki_formatting/common_mark/formatter.rb
+++ b/lib/redmine/wiki_formatting/common_mark/formatter.rb
@@ -42,9 +42,8 @@ module Redmine
 
         # https://github.com/gjtorikian/commonmarker#render-options
         commonmarker_render_options: [
-          :HARDBREAKS,
           :UNSAFE
-        ].freeze,
+        ],
       }.freeze
 
       MarkdownPipeline = HTML::Pipeline.new [
@@ -57,6 +56,12 @@ module Redmine
 
       class Formatter < Redmine::WikiFormatting::Markdown::Formatter
         def to_html(*args)
+          if Setting.text_formatting_common_mark_hardbreaks?
+            PIPELINE_CONFIG[:commonmarker_render_options].push(:HARDBREAKS) unless PIPELINE_CONFIG[:commonmarker_render_options].include?(:HARDBREAKS)
+          else
+            PIPELINE_CONFIG[:commonmarker_render_options].delete(:HARDBREAKS) if PIPELINE_CONFIG[:commonmarker_render_options].include?(:HARDBREAKS)
+          end
+
           result = MarkdownPipeline.call @text
           result[:output].to_s
         end
diff --git a/public/stylesheets/application.css b/public/stylesheets/application.css
index 9f6b4dc3d..0dff30825 100644
--- a/public/stylesheets/application.css
+++ b/public/stylesheets/application.css
@@ -849,6 +849,10 @@ label.block {
   float: none;
 }
 
+.tabular label.block.hidden {
+  display: none;
+}
+
 .tabular label.inline{
   font-weight: normal;
   float:none;
-- 
2.22.0