From b7b8334914fb9397a6725f3b5d2de999b0bb69ac Mon Sep 17 00:00:00 2001
From: Darren Tucker <dtucker@dtucker.net>
Date: Fri, 26 Apr 2019 18:06:34 +1000
Subject: [PATCH] Don't install duplicate STREAMS modules on Solaris

Check if STREAMS modules are already installed on pty before installing
since when compiling with XPG>=4 they will likely be installed already.
Prevents hangs and duplicate lines on the terminal.  bz#2945 and bz#2998,
patch from djm@
---
 openbsd-compat/bsd-openpty.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/openbsd-compat/bsd-openpty.c b/openbsd-compat/bsd-openpty.c
index e8ad542f8..123a9be56 100644
--- a/openbsd-compat/bsd-openpty.c
+++ b/openbsd-compat/bsd-openpty.c
@@ -121,6 +121,15 @@ openpty(int *amaster, int *aslave, char *name, struct termios *termp,
 		return (-1);
 	}
 
+# if defined(I_FIND) && defined(__SVR4)
+	/*
+	 * If the streams modules have already been pushed then there
+	 * is no more work to do here.
+	 */
+	if (ioctl(*aslave, I_FIND, "ptem") != 0)
+		return 0;
+# endif
+
 	/*
 	 * Try to push the appropriate streams modules, as described
 	 * in Solaris pts(7).