I've attached a patch to the upstream bug report: http://bugzilla.abisource.com/show_bug.cgi?id=13008
Looks fine + 07 Aug 2011; Samuli Suominen <ssuominen@gentoo.org> abiword-2.8.6-r1.ebuild, + +files/abiword-2.8.6-libpng15.patch: + Fix building with libpng15 wrt #356287 by Hanno Boeck
*** Bug 380987 has been marked as a duplicate of this bug. ***