Opening a QR Code without background in most image viewers would make them unreadable (tile background is a frequent feature in most image viewers for highlighting transparency; I blame Adobe Photoshop).
There already was a PR but I've decided to copy over my local modifications along with my scalability patch, so this whole PR makes the SVG generation more solid for your great library, Kazuhiko-san.
Opening a QR Code without background in most image viewers would make them unreadable (tile background is a frequent feature in most image viewers for highlighting transparency; I blame Adobe Photoshop). There already was a PR but I've decided to copy over my local modifications along with my scalability patch, so this whole PR makes the SVG generation more solid for your great library, Kazuhiko-san.