12306 XPG4v2 slave pty behaviour should generally be disabled
Reviewed by: Robert Mustacchi <rm@fingolfin.org>
Change-ID: I7ccd399c22866f34dd20c6bb9d28e77ba4e24c67

@@ -20,11 +20,11 @@
  */
 /*
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  * Copyright (c) 2018, Joyent, Inc.
- * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
+ * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T      */
 /* All Rights Reserved                                  */
 

@@ -4085,11 +4085,12 @@
         if (sndsig == 0)
                 (void) putnextctl1(q, mtype, sig);
 
         if (c != '\0') {
                 if ((tp->t_echomp = allocb(4, BPRI_HI)) != NULL) {
-                        if (ldterm_echo(c, WR(q), 4, tp) > 0)
+                        if (ldterm_echo(c, WR(q), 4, tp) > 0 ||
+                            (tp->t_state & TS_ISPTSTTY))
                                 putnext(WR(q), tp->t_echomp);
                         else
                                 freemsg(tp->t_echomp);
                         tp->t_echomp = NULL;
                 }