seabre/pngqr — pull request #2 by azinazadi (2012-04-11 19:53:18+00:00)
Title: automatic border. 

as you can see here: https://www.x.com/devzone/articles/10-best-practices-employing-qr-codes
"
9. Respect the Border
A QR Code comes with a white border around it. Respect that border. The border is an integral part of the code; the code will not scan properly if the border is infringed upon. In addition, the border is what sets your QR Code apart from the content on the page around it, and the code may not be visible without it. Be careful not to overlap that white space with other images or text.
"

the qr code should have a border. so with this change it will have a reasonable border by default, which works fine in most cases. the user can turn the border of by passing :border => 0