accept NULL as a valid string in the proc message formating api.

ok gilles@

diff --git a/usr.sbin/smtpd/mproc.c b/usr.sbin/smtpd/mproc.c
index e50ca37..97da799 100644 (file)
--- a/usr.sbin/smtpd/mproc.c
+++ b/usr.sbin/smtpd/mproc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mproc.c,v 1.29 2017/03/17 20:57:57 eric Exp $ */
+/*     $OpenBSD: mproc.c,v 1.30 2018/11/11 14:00:51 eric Exp $ */
 
 /*
  * Copyright (c) 2012 Eric Faurot <eric@faurot.net>
@@ -441,7 +441,12 @@ m_add_time(struct mproc *m, time_t v)
 void
 m_add_string(struct mproc *m, const char *v)
 {
-       m_add(m, v, strlen(v) + 1);
+       if (v) {
+               m_add(m, "s", 1);
+               m_add(m, v, strlen(v) + 1);
+       }
+       else
+               m_add(m, "\0", 1);
 };
 
 void
@@ -539,10 +544,19 @@ void
 m_get_string(struct msg *m, const char **s)
 {
        uint8_t *end;
+       char c;
 
        if (m->pos >= m->end)
                m_error("msg too short");
 
+       c = *m->pos++;
+       if (c == '\0') {
+               *s = NULL;
+               return;
+       }
+
+       if (m->pos >= m->end)
+               m_error("msg too short");
        end = memchr(m->pos, 0, m->end - m->pos);
        if (end == NULL)
                m_error("unterminated string");