bpo-26228: [doc] Adapt PTY documentation updates from GH-4167 (GH-27754)

Co-authored-by: Cornelius Diekmann <c.diekmann@googlemail.com>
(cherry picked from commit dd8eb30)

Co-authored-by: Łukasz Langa <lukasz@langa.pl>

Author: miss-islington

Doc/library/pty.rst

@@ -2,8 +2,8 @@
 ========================================
 
 .. module:: pty
-   :platform: Linux
-   :synopsis: Pseudo-Terminal Handling for Linux.
+   :platform: Unix
+   :synopsis: Pseudo-Terminal Handling for Unix.
 
 .. moduleauthor:: Steen Lumholt
 .. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
@@ -16,9 +16,9 @@ The :mod:`pty` module defines operations for handling the pseudo-terminal
 concept: starting another process and being able to write to and read from its
 controlling terminal programmatically.
 
-Because pseudo-terminal handling is highly platform dependent, there is code to
-do it only for Linux. (The Linux code is supposed to work on other platforms,
-but hasn't been tested yet.)
+Pseudo-terminal handling is highly platform dependent. This code is mainly
+tested on Linux, FreeBSD, and macOS (it is supposed to work on other POSIX
+platforms but it's not been thoroughly tested).
 
 The :mod:`pty` module defines the following functions:
 
@@ -47,6 +47,10 @@ The :mod:`pty` module defines the following functions:
    spawned behind the pty will eventually terminate, and when it does *spawn*
    will return.
 
+   A loop copies STDIN of the current process to the child and data received
+   from the child to STDOUT of the current process. It is not signaled to the
+   child if STDIN of the current process closes down.
+
    The functions *master_read* and *stdin_read* are passed a file descriptor
    which they should read from, and they should always return a byte string. In
    order to force spawn to return before the child process exits an

Lib/pty.py

@@ -1,7 +1,7 @@
 """Pseudo terminal utilities."""
 
 # Bugs: No signal handling.  Doesn't set slave termios and window size.
-#       Only tested on Linux.
+#       Only tested on Linux, FreeBSD, and macOS.
 # See:  W. Richard Stevens. 1992.  Advanced Programming in the
 #       UNIX Environment.  Chapter 19.
 # Author: Steen Lumholt -- with additions by Guido.

Misc/NEWS.d/next/Library/2019-02-26-09-31-59.bpo-26228.wyrHKc.rst

@@ -1 +1 @@
-pty.spawn no longer hangs on FreeBSD, OS X, and Solaris.
+pty.spawn no longer hangs on FreeBSD, macOS, and Solaris.