Incorrect syntax should never cause a segfault. In this case
listing multiple comma delimited options after '-o' triggered
the problem. For example:
zpool create -o ashift=12,listsnaps=on
This patch resolves the issue by wrapping the calls which use
hdr with a NULL test.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1118
53c2ec1d1b