illumos gate

in libzfs_dataset.c zfs checks if property string is greater then ZAP_MAXNAMELEN

if (strlen(nvpair_name(elem)) >= ZAP_MAXNAMELEN) {
                zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
                    "property name '%s' is too long"),
                    propname);
                (void) zfs_error(hdl, EZFS_BADPROP, errbuf);
                goto error;
            }

ZAP_MAXNAMELEN is defined as PATH_MAX at 1024

• PATH_MAX is defined by the POSIX standard. All modern systems
• provide it.

getconf -a | grep PATH_MAX
PATH_MAX: 1024
_POSIX_PATH_MAX: 255
_XOPEN_PATH_MAX: 1024

If the PATH_MAX would be increased to 4096 (same as in Linux) this would be sorted and sharenfs would accept longer strings
Tested in linux with zfs and it allows for 4x the same value

ex:
:~# zfs set sharenfs=nosuid,sec=sys,rw=@10.31.6.101:@10.31.6.115:@10.31.6.64/26:@10.32.5.30:@10.32.5.40:@127.0.0.1:@10.32.25.38:@10.32.25.39:@10.32.25.37:@200.200.200.2:@172.21.7.35:@172.21.7.36:@10.41.4.21:@10.41.4.22:@10.41.4.23:@10.41.4.24:@10.41.4.25:@10.41.4.26:@172.28.242.1:@172.28.242.6,root=@10.31.6.101:@10.31.6.115:@10.31.6.64/26:@10.32.5.30:@10.32.5.40:@127.0.0.1:@10.32.25.38:@10.32.25.37:@10.32.25.39:@200.200.200.2:@193.62.193.235:@10.41.9.0/24:@10.31.3.224/27:@10.31.4.27:@10.31.4.28:@192.168.13.87:@193.62.193.202:@193.62.193.205:@193.62.193.197:@193.62.193.198:@193.62.193.201:@10.42.5.40:@10.42.5.50:@10.50.5.254:@10.50.5.0/24:@193.62.193.224/28:@172.21.7.35:@172.21.7.36:@10.41.4.21:@10.41.4.22:@10.41.4.23:@10.41.4.24:@10.41.4.25:@10.41.4.26:@172.28.242.1:@172.28.242.6,ro=@193.62.193.235:@10.41.9.0/24:@10.31.3.224/27:@10.31.4.27:@10.31.4.28:@192.168.13.87:@193.62.193.202:@193.62.193.205:@10.32.5.30:@10.32.5.40:@193.62.193.197:@193.62.193.198:@193.62.193.201:@10.42.5.40:@10.42.5.50:@10.50.5.254:@10.50.5.0/24:@193.62.193.224/28 ovi/tewst2
cannot set property for 'ovi/tewst2': 'sharenfs' is too long