X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fexim_monitor%2Fem_log.c;h=1e1dc7c04c424e76a5d437548ba1a22b920f7fa6;hp=348f0642f4854d97a25266fc02fae9af58484eba;hb=1e1ddfac79fbcd052f199500a6493c7f79cb8462;hpb=276f020fb7d0ce2740e90a749b3a49d0d5f74d3d

diff --git a/src/exim_monitor/em_log.c b/src/exim_monitor/em_log.c
index 348f0642f..1e1dc7c04 100644
--- a/src/exim_monitor/em_log.c
+++ b/src/exim_monitor/em_log.c
@@ -365,8 +365,9 @@ if (log_datestamping)
   {
   uschar log_file_wanted[256];
   /* Do *not* use "%s" here, we need the %D datestamp in the log_file string to
-  be expanded. */
-  string_format(log_file_wanted, sizeof(log_file_wanted), CS log_file);
+  be expanded.  The trailing NULL arg is to quieten preprocessors that need at
+  least one arg for a variadic set in a macro. */
+  string_format(log_file_wanted, sizeof(log_file_wanted), CS log_file, NULL);
   if (Ustrcmp(log_file_wanted, log_file_open) != 0)
     {
     if (LOG != NULL)