From 8d387cbb31720448e982bcde84a1ba1e51830470 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@univ-fcomte.fr>
Date: Wed, 30 Aug 2017 14:41:47 +0200
Subject: [PATCH] Don't mess ev->ap (allows multiple %m in layout).

---
 src/xbt/xbt_log_layout_format.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/xbt/xbt_log_layout_format.c b/src/xbt/xbt_log_layout_format.c
index 18c55ac2ce..7c41b5b706 100644
--- a/src/xbt/xbt_log_layout_format.c
+++ b/src/xbt/xbt_log_layout_format.c
@@ -153,7 +153,10 @@ static int xbt_log_layout_format_doit(xbt_log_layout_t l, xbt_log_event_t ev, co
       case 'm': {               /* user-provided message; LOG4J compliant */
         int sz;
         set_sz_from_precision();
-        int len = vsnprintf(p, sz, msg_fmt, ev->ap);
+        va_list ap;
+        va_copy(ap, ev->ap);
+        int len = vsnprintf(p, sz, msg_fmt, ap);
+        va_end(ap);
         check_overflow(MIN(sz, len));
         break;
       }
-- 
2.20.1