From 024483879bffa61bd64d91f82174cdab22cedad5 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Thu, 13 Aug 2020 17:48:59 +0000
Subject: [PATCH 1/3] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../NEWS.d/next/Library/2020-08-13-17-48-58.bpo-41541.vKJSeV.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2020-08-13-17-48-58.bpo-41541.vKJSeV.rst

diff --git a/Misc/NEWS.d/next/Library/2020-08-13-17-48-58.bpo-41541.vKJSeV.rst b/Misc/NEWS.d/next/Library/2020-08-13-17-48-58.bpo-41541.vKJSeV.rst
new file mode 100644
index 00000000000000..5e49a7c836989c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-08-13-17-48-58.bpo-41541.vKJSeV.rst
@@ -0,0 +1 @@
+Make pty.spawn set window size.
\ No newline at end of file

From 5ebf0f31044081d88b428e55b2f39b1f2acb7cc1 Mon Sep 17 00:00:00 2001
From: Soumendra Ganguly <soumendraganguly@gmail.com>
Date: Tue, 18 Aug 2020 21:40:07 -0500
Subject: [PATCH 2/3] Make pty.spawn set window size

---
 Lib/pty.py | 56 ++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/Lib/pty.py b/Lib/pty.py
index a32432041fa1db..3032a3e260e893 100644
--- a/Lib/pty.py
+++ b/Lib/pty.py
@@ -77,6 +77,27 @@ def slave_open(tty_name):
         pass
     return result
 
+def login_tty(fd):
+    """Makes the calling process a session leader, makes fd its
+    controlling terminal, stdin, stdout, and stderr. Closes fd."""
+    # Establish a new session.
+    os.setsid()
+
+    # Make fd the controlling terminal.
+    try:
+        from fcntl import ioctl
+        ioctl(fd, tty.TIOCSCTTY)
+    except (ImportError, AttributeError, OSError):
+        tmp_fd = os.open(os.ttyname(fd), os.O_RDWR)
+        os.close(tmp_fd)
+
+    # fd becomes stdin/stdout/stderr.
+    os.dup2(fd, STDIN_FILENO)
+    os.dup2(fd, STDOUT_FILENO)
+    os.dup2(fd, STDERR_FILENO)
+    if (fd > STDERR_FILENO):
+        os.close(fd)
+
 def fork():
     """fork() -> (pid, master_fd)
     Fork and make the child a session leader with a controlling terminal."""
@@ -97,20 +118,8 @@ def fork():
     master_fd, slave_fd = openpty()
     pid = os.fork()
     if pid == CHILD:
-        # Establish a new session.
-        os.setsid()
         os.close(master_fd)
-
-        # Slave becomes stdin/stdout/stderr of child.
-        os.dup2(slave_fd, STDIN_FILENO)
-        os.dup2(slave_fd, STDOUT_FILENO)
-        os.dup2(slave_fd, STDERR_FILENO)
-        if (slave_fd > STDERR_FILENO):
-            os.close (slave_fd)
-
-        # Explicitly open the tty to make it become a controlling tty.
-        tmp_fd = os.open(os.ttyname(STDOUT_FILENO), os.O_RDWR)
-        os.close(tmp_fd)
+        login_tty(slave_fd)
     else:
         os.close(slave_fd)
 
@@ -148,14 +157,33 @@ def _copy(master_fd, master_read=_read, stdin_read=_read):
             else:
                 _writen(master_fd, data)
 
+def _setwinsz(fd):
+    """Sets window size.
+    If both stdin and fd are terminals,
+    then set fd's window size to be the
+    same as that of stdin's."""
+    try:
+        from struct import pack
+        from fcntl import ioctl
+        strct = pack('HHHH', 0, 0, 0, 0)
+        winsz = ioctl(STDIN_FILENO, tty.TIOCGWINSZ, strct)
+        ioctl(fd, tty.TIOCSWINSZ, winsz)
+    except (ImportError, AttributeError, OSError):
+        pass
+
 def spawn(argv, master_read=_read, stdin_read=_read):
     """Create a spawned process."""
     if type(argv) == type(''):
         argv = (argv,)
     sys.audit('pty.spawn', argv)
-    pid, master_fd = fork()
+    master_fd, slave_fd = openpty()
+    _setwinsz(slave_fd)
+    pid = os.fork()
     if pid == CHILD:
+        os.close(master_fd)
+        login_tty(slave_fd)
         os.execlp(argv[0], *argv)
+    os.close(slave_fd)
     try:
         mode = tty.tcgetattr(STDIN_FILENO)
         tty.setraw(STDIN_FILENO)

From efca4a109cb9d6621a4dea97c6602d2a7a1d2cec Mon Sep 17 00:00:00 2001
From: Soumendra Ganguly <67527439+8vasu@users.noreply.github.com>
Date: Sat, 19 Sep 2020 17:00:44 -0500
Subject: [PATCH 3/3] Minor modification to _setwinsz()

---
 Lib/pty.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Lib/pty.py b/Lib/pty.py
index 3032a3e260e893..16a4cdd71ef67c 100644
--- a/Lib/pty.py
+++ b/Lib/pty.py
@@ -165,10 +165,14 @@ def _setwinsz(fd):
     try:
         from struct import pack
         from fcntl import ioctl
-        strct = pack('HHHH', 0, 0, 0, 0)
+    except ImportError:
+        return
+    
+    strct = pack('HHHH', 0, 0, 0, 0)
+    try:    
         winsz = ioctl(STDIN_FILENO, tty.TIOCGWINSZ, strct)
         ioctl(fd, tty.TIOCSWINSZ, winsz)
-    except (ImportError, AttributeError, OSError):
+    except (AttributeError, OSError):
         pass
 
 def spawn(argv, master_read=_read, stdin_read=_read):