FFI crash: what am I missing?!

[Sam S. <sd...@gn...>]

1. why can't I pass NIL as a C-POINTER and have CLISP use NULL?!

2. <http://norsys.com/netica_c_api.htm>

(def-c-type environ_ns_ c-pointer)
(def-call-out new-netica-environ_ns
  (:arguments (license c-string) (env c-string) (locn c-string))
  (:return-type environ_ns_)
  (:name "NewNeticaEnviron_ns"))
(def-call-out init-netica_bn
  (:arguments (envp (c-ptr environ_ns_) :in-out) (mesg (c-ptr c-string) :out))
  (:return-type int) (:name "InitNetica_bn"))

for

typedef struct environ__ns environ_ns;
environ_ns* NewNeticaEnviron_ns (const char* license, environ_ns* env, const char* locn);
int InitNetica_bn (environ_ns** envp, char* mesg);

results in:

[1]> (setq netica-env (netica:new-netica-environ_ns "foo" nil nil))
#<FOREIGN-ADDRESS #x100C7A70>
[2]> (multiple-value-setq (status netica-env message)
  (netica:init-netica_bn netica-env))

Program received signal SIGSEGV, Segmentation fault.
0x0054aa24 in C_foreign_call_out (argcount=1, rest_args_pointer=0x14600d8) at fo
reign.d:3294
3294            *resptr = convert_from_foreign(*resptr,results[i].address);
(gdb) p results
$1 = (result_descr (*)[0]) 0x6c206568
(gdb) p results[0]
Cannot perform pointer math on incomplete types, try casting to a known type, or
 void *.
(gdb) p results[i].address
Cannot perform pointer math on incomplete types, try casting to a known type, or
 void *.
(gdb)
  
  
-- 
Sam Steingold (http://www.podval.org/~sds) running w2k
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