make posix_spawn accept null pid pointer arguments

this is a requirement in the specification that was overlooked.

diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c
index eb98f9f..f675a13 100644 (file)
--- a/src/process/posix_spawn.c
+++ b/src/process/posix_spawn.c
@@ -166,7 +166,7 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path,
 
        close(args.p[0]);
 
-       if (!ec) *res = pid;
+       if (!ec && res) *res = pid;
 
        pthread_sigmask(SIG_SETMASK, &args.oldmask, 0);
        pthread_setcancelstate(cs, 0);