[libvirt] [PATCH v2] configure: Check for MSG_NOSIGNAL availability

[Andrea Bolognani]

The symbol being missing has been reported as causing build
failures on OS X. Check for its availability before using it.
---
Changes from v1:

  * don't unnecessarily check for availability at configure
    time (thanks Ján)

 src/util/virsystemd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/util/virsystemd.c b/src/util/virsystemd.c
index 969cd68..81ee538 100644
--- a/src/util/virsystemd.c
+++ b/src/util/virsystemd.c
@@ -482,7 +482,7 @@ int virSystemdTerminateMachine(const char *name)
 void
 virSystemdNotifyStartup(void)
 {
-#ifdef HAVE_SYS_UN_H
+#if defined(HAVE_SYS_UN_H) && defined(MSG_NOSIGNAL)
     const char *path;
     const char *msg = "READY=1";
     int fd;
@@ -526,7 +526,7 @@ virSystemdNotifyStartup(void)
         VIR_WARN("Failed to notify systemd");
 
     VIR_FORCE_CLOSE(fd);
-#endif /* HAVE_SYS_UN_H */
+#endif /* defined(HAVE_SYS_UN_H) && defined(MSG_NOSIGNAL) */
 }
 
 static int
-- 
2.7.4