Version 1.3.7 of yafc has been released (https://github.com/sebastinas/yafc/releases). Current version in portage tree is 3 years old.
commit ebafa0a6afa5bda4d7ff98d835bc00377d757b66 Author: Nicholas Vinson <nvinson234@gmail.com> Date: Sun Jan 31 14:00:05 2016 -0500 net-ftp/yafc: Version bump to 1.3.7 Fixes bug #573462