The bug was found with American Fuzzy Lop from optipng (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787647 https://bugs.debian.org/cgi-bin/bugreport.cgi?b

The bug was found with American Fuzzy Lop from optipng (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787647 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787647) and later the optipng author noticed that the same bug also affects libpng (http://sourceforge.net/p/png-mng/mailman/png-mng-implement/thread/CA%2BPdXcuhLXJ89s6qjOEcm%2B99eWLmPBFcYSwcwJkajkLrNRLTeQ%40mail.gmail.com/#msg34581085 http://sourceforge.net/p/png-mng/mailman/png-mng-implement/t...)