🚀 go-pugleaf

Subject: non-[IPC] SMTP mailers broken in sendmail (5.59, 5.61) +FIX
Index:	usr.lib/sendmail/src/deliver.c 4.3BSD

Description:
	Sendmail makes the assumption that any mailer that speaks SMTP,
	ie which has no $u in its argv, is an IPC mailer.  In
	particular it will call getmxrr for the "host" name.  But the
	assumption is wrong.  You can have (and we do) a mailer that is
	a program on the local host and speaks SMTP with sendmail.
	Since this is a "local" mailer, ie its "l" flag is set, there
	is no host associated with it, ie there is no $@host in the
	ruleset zero resolution line for this mailer.  Thus "host" is
	null, getmxrr fails, and sendmail returns "host unknown" even
	though the message is correct and could be delivered.
Repeat-By:
	Create a local mailer that talks SMTP with sendmail.
	Send mail to it.  Watch the "host unknown."
Fix:
	Have sendmail check for a null host name before calling
	getmxrr.  The patch is in deliver.c.  A minor efficiency gain
	is obtained by moving the expand() call to where it's needed.
	These are patches to version 5.61, but the code in earlier
	versions is similar.

*** /tmp/,RCSt1006583	Sun Feb 12 13:04:50 1989
--- deliver.c	Thu Feb  9 18:39:02 1989
***************
*** 379,389 ****
  #ifdef SMTP
  	if (clever)
  	{
- 		expand("\001w", buf, &buf[sizeof(buf) - 1], e);
  		rcode = EX_OK;
  #ifdef NAMED_BIND
! 		if (host[0] != '[')
  		{
  			Nmx = getmxrr(host, MxHosts, buf, &rcode);
  		}
  		else
--- 379,389 ----
  #ifdef SMTP
  	if (clever)
  	{
  		rcode = EX_OK;
  #ifdef NAMED_BIND
! 		if (host[0] && host[0] != '[')
  		{
+ 			expand("\001w", buf, &buf[sizeof(buf) - 1], e);
  			Nmx = getmxrr(host, MxHosts, buf, &rcode);
  		}
  		else