Due to some changes introduced in 30af21b 'zfs send' can crash when
provided with invalid inputs: this change attempts to add more checks
to the affected code paths.
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#9001
1d20b763bb