(oop_sys_run): Added a few assertions to try to figure out why select

	still returns EINVAL sometimes.

src/libraries/liboop/sys.c

@@ -322,6 +322,8 @@ void *oop_sys_run(oop_source_sys *sys) {
 				tv.tv_sec = 0;
 				tv.tv_usec = 0;
 			}
+			assert(tv.tv_usec >= 0);
+			assert(tv.tv_usec < 1000000);
 		}
 
 		if (!sys->sig_active) sys->do_jmp = !sigsetjmp(sys->env,1);
@@ -341,8 +343,16 @@ void *oop_sys_run(oop_source_sys *sys) {
 			if (NULL != sys->files[i][OOP_EXCEPTION].f) FD_SET(i,&xfd);
 		}
 
+		assert(ptv == NULL
+		       || (ptv->tv_usec >= 0 && ptv->tv_usec < 1000000));
 		do
+		{
+			assert(ptv == NULL
+			       || (ptv->tv_usec >= 0
+				   && ptv->tv_usec < 1000000));
+			assert(sys->num_files >= 0);
 			rv = select(sys->num_files,&rfd,&wfd,&xfd,ptv);
+		}
 		while (0 > rv && EINTR == errno);
 
 		sys->do_jmp = 0;