Use UTC in From_ separators in accordance with RFC 4155.

* examples/mta.c (make_tmp): Use gmtime + mu_c_streamftime to
create From_ line.
* libmailutils/mailbox/msgenv.c (message_envelope_date): Use gmtime.
* maidag/deliver.c (make_tmp): Likewise.
* maidag/lmtp.c (cfun_data): Likewise.
* readmsg/readmsg.c (print_unix_header): Use gmtime.

@@ -222,6 +222,7 @@ make_tmp (mu_stream_t in)
   if (n >= 5 && memcmp (buf, "From ", 5))
     {
       time_t t;
+      struct tm *tm;
       const char *from = from_address ();
       if (!from)
 	{
@@ -230,7 +231,9 @@ make_tmp (mu_stream_t in)
 	}
 	  
       time (&t);
-      mu_stream_printf (out, "From %s %s", from, ctime (&t));
+      tm = gmtime (&t);
+      mu_stream_printf (out, "From %s ", from);
+      mu_c_streamftime (out, "%c%n", tm, NULL);
     }
 
   mu_stream_write (out, buf, n, NULL);

@@ -57,7 +57,7 @@ message_envelope_date (mu_envelope_t envelope, char *buf, size_t len,
       char tmpbuf[MU_DATETIME_FROM_LENGTH+1];
       t = time (NULL);
       n = mu_strftime (tmpbuf, sizeof tmpbuf, 
-                       MU_DATETIME_FROM, localtime (&t));
+                       MU_DATETIME_FROM, gmtime (&t));
       n = mu_cpystr (buf, tmpbuf, len);
     }
   if (pnwrite)

@@ -1536,11 +1536,8 @@ imap_envelope_date (mu_envelope_t envelope, char *buffer, size_t buflen,
      parsed, use the calendar time. */
   if (now == (time_t)-1)
     {
-      struct tm *gmt;
-
       time (&now);
-      gmt = gmtime (&now);
-      tm = *gmt;
+      tm = *gmtime (&now);
     }
 
   {

@@ -69,9 +69,12 @@ make_tmp (const char *from)
       if (from)
 	{
 	  time_t t;
+	  struct tm *tm;
 	  
 	  time (&t);
-	  mu_stream_printf (out, "From %s %s", from, ctime (&t));
+	  tm = gmtime (&t);
+	  mu_stream_printf (out, "From %s ", from);
+	  mu_c_streamftime (out, "%c%n", tm, NULL);
 	}
       else
 	{

@@ -346,6 +346,7 @@ cfun_data (mu_stream_t iostr, char *arg)
   int rc;
   mu_stream_t flt, tempstr;
   time_t t;
+  struct tm *tm;
   int xlev = MU_XSCRIPT_PAYLOAD, xlev_switch = 0, buf_switch = 0;
   struct mu_buffer_query oldbuf;
   
@@ -375,7 +376,10 @@ cfun_data (mu_stream_t iostr, char *arg)
 
   /* Write out envelope */
   time (&t);
-  rc = mu_stream_printf (tempstr, "From %s %s", mail_from, ctime (&t));
+  tm = gmtime (&t);
+  rc = mu_stream_printf (tempstr, "From %s ", mail_from);
+  if (rc == 0)
+    rc = mu_c_streamftime (tempstr, "%c%n", tm, NULL);
   if (rc)
     {
       maidag_error (_("copy error: %s"), mu_strerror (rc));

@@ -184,7 +184,7 @@ print_unix_header (mu_message_t message)
       struct tm *tm;
 
       t = time (NULL);
-      tm = localtime (&t);
+      tm = gmtime (&t);
       mu_strftime (datebuf, sizeof datebuf, MU_DATETIME_FROM, tm);
       buf = datebuf;
     }