From: Ian Jackson <iwj@mariner.uk.xensource.com>
Date: Fri, 18 Jul 2008 13:28:52 +0000 (+0100)
Subject: Do not disturb old fd flags (eg O_APPEND) when setting nonblock.
X-Git-Tag: xen-3.3.0-rc1~20^2~1
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=454f34b59e80edd4938686ea3c89a07a86694727;p=qemu-xen-4.0-testing.git

Do not disturb old fd flags (eg O_APPEND) when setting nonblock.

socket_set_nonblock should not unconditionally call
fcntl(,F_SETFL,O_NONBLOCK) because that would clear other flags which
might be intentionally set on the fd.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
---

diff --git a/vl.c b/vl.c
index c428c7e8..0fb9c176 100644
--- a/vl.c
+++ b/vl.c
@@ -2005,7 +2005,9 @@ static inline int send_all(int fd, const uint8_t *buf, int len1)
 
 void socket_set_nonblock(int fd)
 {
-    fcntl(fd, F_SETFL, O_NONBLOCK);
+    int f;
+    f = fcntl(fd, F_GETFL);
+    fcntl(fd, F_SETFL, f | O_NONBLOCK);
 }
 #endif /* !_WIN32 */