Problem: calling zmq_poller_wait* with NULL events causes an assertion, as…

Problem: calling zmq_poller_wait* with NULL events causes an assertion, as opposed to other NULL arguments, which return an error

Solution: return EFAULT when such an operation is attempted

src/zmq.cpp

@@ -1349,38 +1349,42 @@ int zmq_poller_remove_fd (void *poller_, int fd_)
 }
 
 
-int zmq_poller_wait (void *poller_, zmq_poller_event_t *event, long timeout_)
+int zmq_poller_wait (void *poller_, zmq_poller_event_t *event_, long timeout_)
 {
     if (!poller_ || !((zmq::socket_poller_t*)poller_)->check_tag ()) {
         errno = EFAULT;
         return -1;
     }
+    if (!event_) {
+        errno = EFAULT;
+        return -1;
+    }
 
-    zmq_assert (event != NULL);
-
-    int rc = zmq_poller_wait_all(poller_, event, 1, timeout_);
+    int rc = zmq_poller_wait_all(poller_, event_, 1, timeout_);
 
     if (rc < 0) {
-        memset (event, 0, sizeof(zmq_poller_event_t));
+        memset (event_, 0, sizeof(zmq_poller_event_t));
     }
     // wait_all returns number of events, but we return 0 for any success
     return rc >= 0 ? 0 : rc;
 }
 
-int zmq_poller_wait_all (void *poller_, zmq_poller_event_t *events, int n_events, long timeout_)
+int zmq_poller_wait_all (void *poller_, zmq_poller_event_t *events_, int n_events, long timeout_)
 {
     if (!poller_ || !((zmq::socket_poller_t*)poller_)->check_tag ()) {
         errno = EFAULT;
         return -1;
     }
+    if (!events_) {
+        errno = EFAULT;
+        return -1;
+    }
     if (n_events < 0) {
         errno = EINVAL;
         return -1;
     }
 
-    zmq_assert (events != NULL);
-
-    int rc = ((zmq::socket_poller_t*)poller_)->wait ((zmq::socket_poller_t::event_t *)events, n_events, timeout_);
+    int rc = ((zmq::socket_poller_t*)poller_)->wait ((zmq::socket_poller_t::event_t *)events_, n_events, timeout_);
 
     return rc;
 }

tests/test_poller.cpp

@@ -144,15 +144,11 @@ void test_null_event_pointers (void *ctx)
     int rc = zmq_poller_add (poller, socket, NULL, ZMQ_POLLIN);
     assert (rc == 0);
 
-    //  TODO this causes an assertion, which is not consistent with the 
-    //  behavior for other NULL parameters
-#if 0
-    rc = zmq_poller_wait(poller, NULL, 0);
+    rc = zmq_poller_wait (poller, NULL, 0);
     assert (rc == -1 && errno == EFAULT);
 
     rc = zmq_poller_wait_all (poller, NULL, 1, 0);
     assert (rc == -1 && errno == EFAULT);
-#endif
 
     //  TODO this causes an assertion, which is not consistent if the number 
     //  of events may be 0, the pointer should be allowed to by NULL in that