--- a/dav/sync.c	Tue Feb 26 10:29:14 2019 +0100
+++ b/dav/sync.c	Tue Feb 26 10:34:10 2019 +0100
@@ -2110,7 +2110,7 @@
     dav_rand_bytes(name_prefix, 8);   
     char *pre = util_hexstr(name_prefix, 8);
     int64_t ts = (int64_t)time(NULL);
-    int w = snprintf(buf, len, "%s-%"PRId64"\0", pre, ts);
+    int w = snprintf(buf, len, "%s-%"PRId64"%c", pre, ts, '\0');
     free(pre);
     return w >= len;
 }