Redmine

The cause of this issue is that the condition for unless in the following code (at source:tags/5.1.1/lib/redmine/wiki_formatting/common_mark/helper.rb#L29) always returns false. The leading slash in the path value of help_file variable causes the problem.

          help_file = "/help/#{current_language.to_s.downcase}/wiki_syntax_common_mark.html" 
          # fall back to the english help page if there is none for the current
          # language
          unless File.readable? Rails.public_path.join(help_file)
            help_file = "/help/en/wiki_syntax_common_mark.html" 
          end
          end

The following change fixes the issue.

diff --git a/lib/redmine/wiki_formatting/common_mark/helper.rb b/lib/redmine/wiki_formatting/common_mark/helper.rb
index 28e2fe10a..c14fe3f6a 100644
--- a/lib/redmine/wiki_formatting/common_mark/helper.rb
+++ b/lib/redmine/wiki_formatting/common_mark/helper.rb
@@ -23,13 +23,13 @@ module Redmine
       module Helper
         def wikitoolbar_for(field_id, preview_url = preview_text_path)
           heads_for_wiki_formatter
-          help_file = "/help/#{current_language.to_s.downcase}/wiki_syntax_common_mark.html" 
+          help_file = "help/#{current_language.to_s.downcase}/wiki_syntax_common_mark.html" 
           # fall back to the english help page if there is none for the current
           # language
-          unless File.readable? Rails.public_path.join(help_file)
-            help_file = "/help/en/wiki_syntax_common_mark.html" 
+          unless Rails.public_path.join(help_file).readable?
+            help_file = "help/en/wiki_syntax_common_mark.html" 
           end
-          url = "#{Redmine::Utils.relative_url_root}#{help_file}" 
+          url = File.join(Redmine::Utils.relative_url_root, help_file)
           javascript_tag(
             "var wikiToolbar = new jsToolBar(document.getElementById('#{field_id}')); " \
             "wikiToolbar.setHelpLink('#{escape_javascript url}'); " \