From 06a6d290fd4583a6f07d3a3a582d04a8e1c265e6 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sun, 25 Jun 2017 11:08:53 -0600
Subject: [PATCH] rktio: fix bug merging fd sets when poll() is not available

---
 racket/src/rktio/rktio_poll_set.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/racket/src/rktio/rktio_poll_set.c b/racket/src/rktio/rktio_poll_set.c
index b2ea330260..6f196f666e 100644
--- a/racket/src/rktio/rktio_poll_set.c
+++ b/racket/src/rktio/rktio_poll_set.c
@@ -825,7 +825,8 @@ void rktio_merge_fd_sets(rktio_poll_set_t *fds, rktio_poll_set_t *src_fds)
     p = (unsigned char *)rktio_get_fdset(fds, j);
     sp = (unsigned char *)rktio_get_fdset(src_fds, j);
 # ifdef STORED_ACTUAL_FDSET_LIMIT
-    if (FDSET_LIMIT(sp) > FDSET_LIMIT(p)) {
+    i = FDSET_LIMIT(p);
+    if (FDSET_LIMIT(sp) > i) {
       i = FDSET_LIMIT(sp);
       FDSET_LIMIT(p) = i;
     }