sshd sets ssh client tty mode to original state after a tty session has ended

this is a needed step for our sshd in tty mode as we ask clients to send
us CRLF as command terminator. But we must reset the mode when the tty
session ends so that sftp running after it does not encounter CRLF mode.
Linux openssh sftp client otherwise would show two lines for each
command typed when run after an ssh session to our server.

Author: quamrulmina

nchan.c

@@ -187,8 +187,24 @@ chan_ibuf_empty(Channel *c)
 	switch (c->istate) {
 	case CHAN_INPUT_WAIT_DRAIN:
 		if (compat20) {
-			if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_LOCAL)))
+			if (!(c->flags & (CHAN_CLOSE_SENT | CHAN_LOCAL))) {
+				#ifdef WIN32_FIXME
+				// reset the other side if tty to be how it was before
+				if (c->isatty) {
+					char *inittermseq =
+						"\033[?7h" // end-of-line autowrap ON mode
+						"\033[20l"; // force NewLineMode off
+
+					buffer_append(&c->input, inittermseq, strlen(inittermseq));
+					int state = c->istate;
+					c->istate = CHAN_INPUT_WAIT_DRAIN;
+					channel_output_poll();
+					packet_write_poll(); // packet_write_wait();
+					c->istate = state;
+				}
+				#endif
 				chan_send_eof2(c);
+			}
 			chan_set_istate(c, CHAN_INPUT_CLOSED);
 		} else {
 			chan_send_ieof1(c);

serverloop.c

@@ -880,13 +880,6 @@ collect_children(void)
 
         process = s->pid;
 
-		// send the other side terminal to be how it was before if it was tty
-		if ( (!s -> is_subsystem) && (s ->ttyfd != -1)) {
-			char *inittermseq = "\033[20l\033[?7h\0" ; // no LFtoCRLF no AUTOWRAPON
-			Channel *c=channel_by_id ( s->chanid );
-			buffer_append(&c->input, inittermseq, strlen(inittermseq));
-			packet_write_poll();
-		}
         session_close_by_pid(s->pid, status);
 
         if (s->pid)