I've updated my lensfun database with the recently added Canon S100 camera (see https://www.openhub.net/p/lensfun/commits/383464283 ). The command
ufraw-batch --lensfun=auto etc etc etc
does not seem to do the barrel correction for images like http://www.dpreview.com/forums/post/51970815 where the pole at athe right-hand side is badly bent. The "gimplensfun" plugin works in GIMP, so I know that lensfun works with the Canon S100. I believe that narrows the problem down to ufraw-batch not detecting the camera data properly. I'm attaching gzipped...
If you want, I can also send the original .CR2 raw file... WARNING; it's almost 13 megabytes. I can post it elsewhere for you to download if that's easier.