From 4c8b7cdc64d054e18be3bd6e3f85d277927c639c Mon Sep 17 00:00:00 2001
From: Jardel Weyrich <jweyrich@users.sourceforge.net>
Date: Mon, 28 Dec 2009 16:00:05 -0500
Subject: [PATCH] Make evutil_make_socket_nonblocking() leave any other flags
 alone.

Fixes bug 2922121
---
 evutil.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/evutil.c b/evutil.c
index f1480db5..381e17fa 100644
--- a/evutil.c
+++ b/evutil.c
@@ -184,9 +184,16 @@ evutil_make_socket_nonblocking(evutil_socket_t fd)
 		ioctlsocket(fd, FIONBIO, (unsigned long*) &nonblocking);
 	}
 #else
-	if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
-		event_warn("fcntl(O_NONBLOCK)");
-		return -1;
+	{
+		long flags;
+		if ((flags = fcntl(fd, F_GETFL, NULL)) < 0) {
+			event_warn("fcntl(F_GETFL)");
+			return -1;
+		}
+		if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
+			event_warn("fcntl(O_NONBLOCK)");
+			return -1;
+		}
 	}
 #endif
 	return 0;