When we copy the envblock's contents out, we currently treat it as
a normal C string. However, this functionality is supposed to more
closely emulate interacting with a file. As a consequence, we were
incorrectly truncating the contents of the envblock by replacing
the final byte of the buffer with a null character.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#10405
b2f3709c3e