1 files changed, 189 insertions, 0 deletions
diff --git a/test/integration/targets/fork_safe_stdio/vendored_pty.py b/test/integration/targets/fork_safe_stdio/vendored_pty.py
new file mode 100644
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--- /dev/null
+++ b/test/integration/targets/fork_safe_stdio/vendored_pty.py
@@ -0,0 +1,189 @@
+# Vendored copy of https://github.com/python/cpython/blob/3680ebed7f3e529d01996dd0318601f9f0d02b4b/Lib/pty.py
+# PSF License (see licenses/PSF-license.txt or https://opensource.org/licenses/Python-2.0)
+"""Pseudo terminal utilities."""
+
+# Bugs: No signal handling.  Doesn't set slave termios and window size.
+#       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.
+
+from select import select
+import os
+import sys
+import tty
+
+# names imported directly for test mocking purposes
+from os import close, waitpid
+from tty import setraw, tcgetattr, tcsetattr
+
+__all__ = ["openpty", "fork", "spawn"]
+
+STDIN_FILENO = 0
+STDOUT_FILENO = 1
+STDERR_FILENO = 2
+
+CHILD = 0
+
+def openpty():
+    """openpty() -> (master_fd, slave_fd)
+    Open a pty master/slave pair, using os.openpty() if possible."""
+
+    try:
+        return os.openpty()
+    except (AttributeError, OSError):
+        pass
+    master_fd, slave_name = _open_terminal()
+    slave_fd = slave_open(slave_name)
+    return master_fd, slave_fd
+
+def master_open():
+    """master_open() -> (master_fd, slave_name)
+    Open a pty master and return the fd, and the filename of the slave end.
+    Deprecated, use openpty() instead."""
+
+    try:
+        master_fd, slave_fd = os.openpty()
+    except (AttributeError, OSError):
+        pass
+    else:
+        slave_name = os.ttyname(slave_fd)
+        os.close(slave_fd)
+        return master_fd, slave_name
+
+    return _open_terminal()
+
+def _open_terminal():
+    """Open pty master and return (master_fd, tty_name)."""
+    for x in 'pqrstuvwxyzPQRST':
+        for y in '0123456789abcdef':
+            pty_name = '/dev/pty' + x + y
+            try:
+                fd = os.open(pty_name, os.O_RDWR)
+            except OSError:
+                continue
+            return (fd, '/dev/tty' + x + y)
+    raise OSError('out of pty devices')
+
+def slave_open(tty_name):
+    """slave_open(tty_name) -> slave_fd
+    Open the pty slave and acquire the controlling terminal, returning
+    opened filedescriptor.
+    Deprecated, use openpty() instead."""
+
+    result = os.open(tty_name, os.O_RDWR)
+    try:
+        from fcntl import ioctl, I_PUSH
+    except ImportError:
+        return result
+    try:
+        ioctl(result, I_PUSH, "ptem")
+        ioctl(result, I_PUSH, "ldterm")
+    except OSError:
+        pass
+    return result
+
+def fork():
+    """fork() -> (pid, master_fd)
+    Fork and make the child a session leader with a controlling terminal."""
+
+    try:
+        pid, fd = os.forkpty()
+    except (AttributeError, OSError):
+        pass
+    else:
+        if pid == CHILD:
+            try:
+                os.setsid()
+            except OSError:
+                # os.forkpty() already set us session leader
+                pass
+        return pid, fd
+
+    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)
+    else:
+        os.close(slave_fd)
+
+    # Parent and child process.
+    return pid, master_fd
+
+def _writen(fd, data):
+    """Write all the data to a descriptor."""
+    while data:
+        n = os.write(fd, data)
+        data = data[n:]
+
+def _read(fd):
+    """Default read function."""
+    return os.read(fd, 1024)
+
+def _copy(master_fd, master_read=_read, stdin_read=_read):
+    """Parent copy loop.
+    Copies
+            pty master -> standard output   (master_read)
+            standard input -> pty master    (stdin_read)"""
+    fds = [master_fd, STDIN_FILENO]
+    while fds:
+        rfds, _wfds, _xfds = select(fds, [], [])
+
+        if master_fd in rfds:
+            # Some OSes signal EOF by returning an empty byte string,
+            # some throw OSErrors.
+            try:
+                data = master_read(master_fd)
+            except OSError:
+                data = b""
+            if not data:  # Reached EOF.
+                return    # Assume the child process has exited and is
+                          # unreachable, so we clean up.
+            else:
+                os.write(STDOUT_FILENO, data)
+
+        if STDIN_FILENO in rfds:
+            data = stdin_read(STDIN_FILENO)
+            if not data:
+                fds.remove(STDIN_FILENO)
+            else:
+                _writen(master_fd, data)
+
+def spawn(argv, master_read=_read, stdin_read=_read):
+    """Create a spawned process."""
+    if isinstance(argv, str):
+        argv = (argv,)
+    sys.audit('pty.spawn', argv)
+
+    pid, master_fd = fork()
+    if pid == CHILD:
+        os.execlp(argv[0], *argv)
+
+    try:
+        mode = tcgetattr(STDIN_FILENO)
+        setraw(STDIN_FILENO)
+        restore = True
+    except tty.error:    # This is the same as termios.error
+        restore = False
+
+    try:
+        _copy(master_fd, master_read, stdin_read)
+    finally:
+        if restore:
+            tcsetattr(STDIN_FILENO, tty.TCSAFLUSH, mode)
+
+    close(master_fd)
+    return waitpid(pid, 0)[1]