Notification on updated Description or Environment field does not render the wiki markup

When a user updated a description for an issue, the notification email does not rendered the wiki markup. For example, the description field is updated:

Then, on the notification email, the content does not rendered the wiki markup:

Note:

• The field description is already configured to Wiki Style Renderer
• Tested on JIRA 5.1.2, 5.1.3, 5.2.4, 6.1.2, 6.1.5
• When creating the issue, the first notification formats correctly
• Subsequent updates will not render the wiki markup
• Any new comments on the issue will show the description un-rendered in the notifications, but will show the comment rendered correctly if there is any wiki formatting in the comment.
• Any edits on existing comments will not render the wiki markup