From 364ab3daf6d00dfa8e0dd81046f741e70cac5da9 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Thu, 5 Mar 2015 10:28:41 +0100
Subject: [PATCH] dbg: save errno from modification in NL_DBG()

Evaluating the logging statement might overwrite the errno. Save and
restore it so that NL_DBG() preserves the errno.

Signed-off-by: Thomas Haller <thaller@redhat.com>
---
 include/netlink-private/netlink.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/netlink-private/netlink.h b/include/netlink-private/netlink.h
index 39f4dff..b06df8b 100644
--- a/include/netlink-private/netlink.h
+++ b/include/netlink-private/netlink.h
@@ -86,11 +86,14 @@ struct trans_list {
 #ifdef NL_DEBUG
 #define NL_DBG(LVL,FMT,ARG...)						\
 	do {								\
-		if (LVL <= nl_debug)					\
+		if (LVL <= nl_debug) {					\
+			int _errsv = errno;				\
 			fprintf(stderr,					\
 				"DBG<" #LVL ">%20s:%-4u %s: " FMT,	\
 				__FILE__, __LINE__,			\
 				__PRETTY_FUNCTION__, ##ARG);		\
+			errno = _errsv;					\
+		}							\
 	} while (0)
 #else /* NL_DEBUG */
 #define NL_DBG(LVL,FMT,ARG...) do { } while(0)