SOn markers and Singleshot

I posted a photo to photos.xythian.com. It didn’t work. Some digging indicated that Singleshot’s JPEG height/width detection was failing on the new JPEG.

Singleshot’s JPEG header parsing code was only looking for a SOF0 marker and thus didn’t work on progressive JPEGs (which used SOF2). This is why it’s important to read the spec for file formats you’re reading rather than just cribbing information like “to get the height/width from a JPEG, look for the marker 0xC0 and then pull height and width from that block” from random code