tree 46ad230b3b1a552a2d2b258207997016913a132c
parent bcc6cc5bcadb20005ae03c8c4a4eb87006f0d222
author Adriana Kobylak <anoo@us.ibm.com> 1547138144 -0600
committer Adriana Kobylak <anoo@us.ibm.com> 1561394918 -0500

nbd-proxy: Increment refcount in print_metadata()

The json_object.h states that json_object_object_get_ex() does not
increase the reference count:
https://github.com/json-c/json-c/blob/json-c-0.11/json_object.h#L271

With the latest json-c-0.13.1, an assert check was added, so calling
json_object_put() to free an object created with json_object_object_get_ex()
causes an app crash:

root@witherspoon:~# nbd-proxy --metadata
{ "0": { "description": "Virtual media device" } }
nbd-proxy: ../json-c-0.13.1/json_object.c:189: json_object_put: Assertion `jso->_ref_count > 0' failed.
Aborted

Need to increase the refcount in print_metadata() via json_object_get()
so that the json_object_put() there does not free the metadata.

Tested: Verified no error is seeing anymore:
        root@witherspoon:/tmp# ./nbd-proxy --metadata
        { "0": { "description": "Virtual media device" } }

Change-Id: Ic48b98813a45f993cf00415243769533b2576cab
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>