fixed a bug in the regex pattern to converts tabs and spaces into a single space

http://codeigniter.com/bug_tracker/bug/6662/
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index d9017d9..a0a54a3 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -110,6 +110,7 @@
 			<li>Fixed a bug when using DB cache on multiple databases (#5737).</li>
 			<li>Fixed a bug where TRUNCATE was not considered a "write" query (#6619).</li>
 			<li>Fixed a bug where csv_from_result() was checking for a nonexistent method.</li>
+			<li>Fixed a bug _protect_identifiers() where it was improperly removing all pipe symbols from items</li>
 		</ul>
 	</li>
 	<li>Fixed assorted user guide typos or examples (#5998, #6093, #6259, #6339, #6432, #6521).</li>