Input string foo: can crash the parser with a SIGSEGV. The crash is into member_to_object function.

(gdb) run foo:
Starting program: /dev/shm/jo/jo foo:
Program received signal SIGSEGV, Segmentation fault.
0x0000000000404200 in member_to_object (object=, flags=0, kv=0x7fffffffe87e "foo:") at jo.c:335
335 *q = 0;
(gdb)
(gdb) print /x q
$6 = 0x0

q variable is initialized at jo.c:294 but could be null.