Linkify message:// URLs in notes. Those links are used by Mail.app on

Mac OS X to link to a mail message by message id.

app/helpers/todos_helper.rb

@@ -324,5 +324,29 @@ module TodosHelper
   def auto_complete_result2(entries, phrase = nil)
     return entries.map{|e| e.specification()}.join("\n") rescue ''
   end
-  
+
+  AUTO_LINK_MESSAGE_RE = %r{message://<[^>]+>} unless const_defined?(:AUTO_LINK_MESSAGE_RE)
+
+  # Converts message:// links to href. This URL scheme is used on Mac OS X
+  # to link to a mail message in Mail.app.
+  def auto_link_message(text)
+    text.gsub(AUTO_LINK_MESSAGE_RE) do
+      href = $&
+      left, right = $`, $'
+      # detect already linked URLs and URLs in the middle of a tag
+      if left =~ /<[^>]+$/ && right =~ /^[^>]*>/
+        # do not change string; URL is alreay linked
+        href
+      else
+        content_tag(:a, h(href), :href => h(href))
+      end
+    end
+  end
+
+  def format_note(note)
+    note = auto_link_message(note)
+    note = auto_link(note)
+    note = markdown(note)
+    note = sanitize(note)
+  end
 end

app/views/notes/_notes.rhtml

@@ -2,8 +2,8 @@
 <div id="<%= dom_id(note, 'container') %>">
   <h2><%= link_to("Note #{note.id}", note_path(note), :title => "Show note #{note.id}" ) %></h2>
   <div class="project_notes" id="<%= dom_id(note) %>">
-    <%= sanitize(markdown(auto_link(note.body))) %>
-       
+    <%= format_note(note.body) %>
+
     <div class="note_footer">
       <%= link_to_remote( 
         image_tag("blank.png", 

app/views/todos/_toggle_notes.rhtml

@@ -1,5 +1,5 @@
 <%= link_to(image_tag( 'blank.png', :width=>'16', :height=>'16', :border=>'0' ), "#", {:class => 'show_notes', :title => 'Show notes'}) %>
 
 <div class="todo_notes" id="<%= dom_id(item, 'notes') %>" style="display:none">
-  <%= sanitize(markdown( auto_link(item.notes)) ) %>
+  <%= format_note(item.notes) %>
 </div>