Patch is available in $URL.
*inkscape-0.91_pre3-r2 (03 Jan 2015) 03 Jan 2015; Manuel Rüger <mrueg@gentoo.org> +files/inkscape-0.91_pre3-poppler-0.29.patch, +inkscape-0.91_pre3-r2.ebuild: Fix build with poppler-0.29. See bug #534352