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

*** 26,36 ****
   * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
   */
  
  /*
   * Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved.
!  * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
   */
  
  /*      Copyright (c) 1988 AT&T */
  /*        All Rights Reserved   */
  
--- 26,36 ----
   * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
   */
  
  /*
   * Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved.
!  * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
   */
  
  /*      Copyright (c) 1988 AT&T */
  /*        All Rights Reserved   */
  
*** 248,257 ****
--- 248,270 ----
  extern int posix_openpt(int);
  extern int setenv(const char *, const char *, int);
  extern int unsetenv(const char *);
  #endif
  
+ /*
+  * In strict XPG4v2 mode, slave pseudo terminal devices behave differently.
+  * See the block comment in usr/src/lib/libc/port/gen/pt.c
+  */
+ #if defined(_STRICT_SYMBOLS) && defined(_XPG4_2)
+ #ifdef  __PRAGMA_REDEFINE_EXTNAME
+ #pragma redefine_extname unlockpt __unlockpt_xpg4
+ #else
+ extern int __unlockpt_xpg4(int);
+ #define unlockpt __unlockpt_xpg4
+ #endif
+ #endif  /* defined(_STRICT_SYMBOLS) && defined(_XPG4_2) */
+ 
  #if defined(__EXTENSIONS__) || \
          (!defined(_STRICT_STDC) && !defined(__XOPEN_OR_POSIX))
  extern char *canonicalize_file_name(const char *);
  extern int clearenv(void);
  extern void closefrom(int);