esl/ejabberd — pull request #73 by arcusfelis (2013-04-19 18:34:52+00:00)
Title: Requests for empty string preparation will not be passed to the port driver.

String preparation is a popular operation. Strings are often empty too (for example, we have a JID without resource). This commit is a tiny optimization to not disturb the port driver, when the case is trivial.