/usr/share/help/sl/xchat-gnome/index.docbook is in xchat-gnome-common 1:0.30.0~git20141005.816798-0ubuntu9.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/help/sl/xchat-gnome/../../../help-langpack/sl/xchat-gnome/index.docbook