From 8b4263b2e270778dbcc2c6c559ffac1d6ddaf418 Mon Sep 17 00:00:00 2001
From: Marius BALTEANU <marius.balteanu@zitec.com>
Date: Tue, 27 Jul 2021 02:25:27 +0300
Subject: [PATCH] Add setting to controll the hardbreaks behaviour from admin
 (#32424).


diff --git a/app/views/settings/_general.html.erb b/app/views/settings/_general.html.erb
index 23abdb3f5..a776aca76 100644
--- a/app/views/settings/_general.html.erb
+++ b/app/views/settings/_general.html.erb
@@ -19,7 +19,16 @@
 
 <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 %>
+  <span id="common_mark_info" class="<%= "hidden" unless Setting.text_formatting == "common_mark" %>">
+    <em class="info">
+        <strong>Hardbreaks:</strong> <%= Redmine::Configuration['common_mark_enable_hardbreaks'] === true ? l(:label_enabled) : l(:label_disabled) %>.
+    </em>
+    <em class="info">
+      You can configure the behaviour in config/configuration.yml. Please restart the application after editing it.
+    </em>
+  </span>
+</p>
 
 <p><%= setting_check_box :cache_formatted_text %></p>
 
@@ -32,3 +41,16 @@
 
 <%= submit_tag l(:button_save) %>
 <% end %>
+
+<%= javascript_tag do %>
+  $('#settings_text_formatting').on('change', function(e){
+    const formatter = e.target.value;
+    const parent_block = document.getElementById("common_mark_info");
+
+    if (formatter == "common_mark") {
+      parent_block.classList.remove('hidden');
+    } else {
+      parent_block.classList.add('hidden');
+    }
+  });
+<% end %>
diff --git a/config/configuration.yml.example b/config/configuration.yml.example
index 8e350228e..e1dbb19c2 100644
--- a/config/configuration.yml.example
+++ b/config/configuration.yml.example
@@ -224,6 +224,13 @@ default:
   #avatar_server_url: https://www.gravatar.com        # default
   #avatar_server_url: https://seccdn.libravatar.org
 
+  # Configure CommonMark hardbreaks behaviour
+  #
+  # allowed values: true, false
+  # true: treats regular line break (\n) as hardbreaks
+  # false: switches to default common mark where two or more spaces are required
+  # common_mark_enable_hardbreaks: true
+
 # specific configuration options for production environment
 # that overrides the default ones
 production:
diff --git a/config/locales/en.yml b/config/locales/en.yml
index e72e1bf89..f4f0671b7 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -893,6 +893,7 @@ en:
   label_copied_to: Copied to
   label_copied_from: Copied from
   label_stay_logged_in: Stay logged in
+  label_enabled: enabled
   label_disabled: disabled
   label_optional: optional
   label_show_completed_versions: Show completed versions
diff --git a/lib/redmine/configuration.rb b/lib/redmine/configuration.rb
index 883dc8497..aff2651bb 100644
--- a/lib/redmine/configuration.rb
+++ b/lib/redmine/configuration.rb
@@ -24,7 +24,8 @@ module Redmine
     @defaults = {
       'avatar_server_url' => 'https://www.gravatar.com',
       'email_delivery' => nil,
-      'max_concurrent_ajax_uploads' => 2
+      'max_concurrent_ajax_uploads' => 2,
+      'common_mark_enable_hardbreaks' => true
     }
 
     @config = nil
diff --git a/lib/redmine/wiki_formatting/common_mark/formatter.rb b/lib/redmine/wiki_formatting/common_mark/formatter.rb
index d0db8c9b8..3c2f3ad09 100644
--- a/lib/redmine/wiki_formatting/common_mark/formatter.rb
+++ b/lib/redmine/wiki_formatting/common_mark/formatter.rb
@@ -43,9 +43,14 @@ module Redmine
         # https://github.com/gjtorikian/commonmarker#render-options
         commonmarker_render_options: [
           :UNSAFE
-        ].freeze,
+        ],
       }.freeze
 
+      if Redmine::Configuration['common_mark_enable_hardbreaks'] === true
+        PIPELINE_CONFIG[:commonmarker_render_options].push(:HARDBREAKS)
+      end
+      PIPELINE_CONFIG[:commonmarker_render_options].freeze
+
       MarkdownPipeline = HTML::Pipeline.new [
         MarkdownFilter,
         SanitizationFilter,
-- 
2.22.0