const correctness in mq_notify

why did gcc allow this invalid assignment to compile in the first place?

diff --git a/src/mq/mq_notify.c b/src/mq/mq_notify.c
index 60bb2db..3f8661e 100644 (file)
--- a/src/mq/mq_notify.c
+++ b/src/mq/mq_notify.c
@@ -61,7 +61,7 @@ int mq_notify(mqd_t mqd, const struct sigevent *sev)
 
        sev2.sigev_notify = SIGEV_THREAD;
        sev2.sigev_signo = s;
-       sev2.sigev_value.sival_ptr = &zeros;
+       sev2.sigev_value.sival_ptr = (void *)&zeros;
 
        if (syscall(SYS_mq_notify, mqd, &sev2) < 0) {
                pthread_cancel(td);