/usr/share/man/man3/XConvertSelection.3.gz is in libx11-doc 2:1.5.0-1+deb7u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man3/XSetSelectionOwner.3.gz
/usr/share/man/man3/XSetSelectionOwner.3.gz