Hi!
This patch adds the option to separate xpath results from xmllint by a 
null delimiter when using the --xpath0 option-flag. It is something 
that's been asked for for a long time by users on stackoverflow and 
merge-attempts have been made to upstream without success.

Examples:
   - https://gitlab.gnome.org/GNOME/libxml2/-/issues/227
   - https://gitlab.gnome.org/GNOME/libxml2/-/merge_requests/8

Best regards,
David