media-libs/fontconfig 2.12.92 is missing in Portage tree now. It should be added.
New x11-libs/pango 1.42.0 has the following dependency:
Current fontconfig 2.13.* is buggy and cannot work with infinality:
fontconfig-2.13 is in the tree and #650248 is fixed. I think we can close this now. Please reopen with new details, if I am wrong.