EllisLab/CodeIgniter — pull request #675 by has2k1 (2011-11-17 18:05:04+00:00)
Title: auto_link() learned to recognize more URLs 

Problem:
auto_link() only works on URLs that are preceded by a new line, space, or open parentheses. As a result the URL in the string below would be missed.

'Google
http://www.google.com/'

Solution:
Add a word boundary to the list of features that can precede a URL.

Credit to: @scaryuncledevin, issue #419