windows: always work around EINVAL in case of broken pipe for stdout / stderr

In 29a905fe23ae, I missed the fact that the `winstdout` class works around two
unrelated bugs (size limit when writing to consoles and EINVAL in case of
broken pipe) and that the latter bug happens even when no console is involved.
When writing a test for this, I realized that the same problem applies to
stderr, so I applied the workaround for EINVAL to both stdout and stderr.

The size limit is worked around in the same case as before (consoles on Windows
on Python 2). For that, I changed the `winstdout` class.

mercurial/utils/procutil.py

@@ -1,752 +1,758 b''
 # procutil.py - utility for managing processes and executable environment
 #
 #  Copyright 2005 K. Thananchayan <[e-mail]>
 #  Copyright 2005-2007 Matt Mackall <[e-mail]>
 #  Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import contextlib
 import errno
 import io
 import os
 import signal
 import subprocess
 import sys
 import threading
 import time
 
 from ..i18n import _
 from ..pycompat import (
     getattr,
     open,
 )
 
 from .. import (
     encoding,
     error,
     policy,
     pycompat,
 )
 
 # Import like this to keep import-checker happy
 from ..utils import resourceutil
 
 osutil = policy.importmod('osutil')
 
 if pycompat.iswindows:
     from .. import windows as platform
 else:
     from .. import posix as platform
 
 
 def isatty(fp):
     try:
         return fp.isatty()
     except AttributeError:
         return False
 
 
 class LineBufferedWrapper(object):
     def __init__(self, orig):
         self.orig = orig
 
     def __getattr__(self, attr):
         return getattr(self.orig, attr)
 
     def write(self, s):
         orig = self.orig
         res = orig.write(s)
         if s.endswith(b'\n'):
             orig.flush()
         return res
 
 
 io.BufferedIOBase.register(LineBufferedWrapper)
 
 
 def make_line_buffered(stream):
     if pycompat.ispy3 and not isinstance(stream, io.BufferedIOBase):
         # On Python 3, buffered streams can be expected to subclass
         # BufferedIOBase. This is definitively the case for the streams
         # initialized by the interpreter. For unbuffered streams, we don't need
         # to emulate line buffering.
         return stream
     if isinstance(stream, LineBufferedWrapper):
         return stream
     return LineBufferedWrapper(stream)
 
 
 class WriteAllWrapper(object):
     def __init__(self, orig):
         self.orig = orig
 
     def __getattr__(self, attr):
         return getattr(self.orig, attr)
 
     def write(self, s):
         write1 = self.orig.write
         m = memoryview(s)
         total_to_write = len(s)
         total_written = 0
         while total_written < total_to_write:
             total_written += write1(m[total_written:])
         return total_written
 
 
 io.IOBase.register(WriteAllWrapper)
 
 
 def _make_write_all(stream):
     assert pycompat.ispy3
     if isinstance(stream, WriteAllWrapper):
         return stream
     if isinstance(stream, io.BufferedIOBase):
         # The io.BufferedIOBase.write() contract guarantees that all data is
         # written.
         return stream
     # In general, the write() method of streams is free to write only part of
     # the data.
     return WriteAllWrapper(stream)
 
 
 if pycompat.ispy3:
     # Python 3 implements its own I/O streams.
     # TODO: .buffer might not exist if std streams were replaced; we'll need
     # a silly wrapper to make a bytes stream backed by a unicode one.
     stdin = sys.stdin.buffer
     stdout = _make_write_all(sys.stdout.buffer)
+    stderr = _make_write_all(sys.stderr.buffer)
+    if pycompat.iswindows:
+        # Work around Windows bugs.
+        stdout = platform.winstdout(stdout)
+        stderr = platform.winstdout(stderr)
     if isatty(stdout):
         # The standard library doesn't offer line-buffered binary streams.
         stdout = make_line_buffered(stdout)
-    stderr = _make_write_all(sys.stderr.buffer)
 else:
     # Python 2 uses the I/O streams provided by the C library.
     stdin = sys.stdin
     stdout = sys.stdout
+    stderr = sys.stderr
+    if pycompat.iswindows:
+        # Work around Windows bugs.
+        stdout = platform.winstdout(stdout)
+        stderr = platform.winstdout(stderr)
     if isatty(stdout):
         if pycompat.iswindows:
-            # Work around size limit when writing to console.
-            stdout = platform.winstdout(stdout)
             # The Windows C runtime library doesn't support line buffering.
             stdout = make_line_buffered(stdout)
         else:
             # glibc determines buffering on first write to stdout - if we
             # replace a TTY destined stdout with a pipe destined stdout (e.g.
             # pager), we want line buffering.
             stdout = os.fdopen(stdout.fileno(), 'wb', 1)
-    stderr = sys.stderr
 
 
 findexe = platform.findexe
 _gethgcmd = platform.gethgcmd
 getuser = platform.getuser
 getpid = os.getpid
 hidewindow = platform.hidewindow
 readpipe = platform.readpipe
 setbinary = platform.setbinary
 setsignalhandler = platform.setsignalhandler
 shellquote = platform.shellquote
 shellsplit = platform.shellsplit
 spawndetached = platform.spawndetached
 sshargs = platform.sshargs
 testpid = platform.testpid
 
 try:
     setprocname = osutil.setprocname
 except AttributeError:
     pass
 try:
     unblocksignal = osutil.unblocksignal
 except AttributeError:
     pass
 
 closefds = pycompat.isposix
 
 
 def explainexit(code):
     """return a message describing a subprocess status
     (codes from kill are negative - not os.system/wait encoding)"""
     if code >= 0:
         return _(b"exited with status %d") % code
     return _(b"killed by signal %d") % -code
 
 
 class _pfile(object):
     """File-like wrapper for a stream opened by subprocess.Popen()"""
 
     def __init__(self, proc, fp):
         self._proc = proc
         self._fp = fp
 
     def close(self):
         # unlike os.popen(), this returns an integer in subprocess coding
         self._fp.close()
         return self._proc.wait()
 
     def __iter__(self):
         return iter(self._fp)
 
     def __getattr__(self, attr):
         return getattr(self._fp, attr)
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, exc_tb):
         self.close()
 
 
 def popen(cmd, mode=b'rb', bufsize=-1):
     if mode == b'rb':
         return _popenreader(cmd, bufsize)
     elif mode == b'wb':
         return _popenwriter(cmd, bufsize)
     raise error.ProgrammingError(b'unsupported mode: %r' % mode)
 
 
 def _popenreader(cmd, bufsize):
     p = subprocess.Popen(
         tonativestr(cmd),
         shell=True,
         bufsize=bufsize,
         close_fds=closefds,
         stdout=subprocess.PIPE,
     )
     return _pfile(p, p.stdout)
 
 
 def _popenwriter(cmd, bufsize):
     p = subprocess.Popen(
         tonativestr(cmd),
         shell=True,
         bufsize=bufsize,
         close_fds=closefds,
         stdin=subprocess.PIPE,
     )
     return _pfile(p, p.stdin)
 
 
 def popen2(cmd, env=None):
     # Setting bufsize to -1 lets the system decide the buffer size.
     # The default for bufsize is 0, meaning unbuffered. This leads to
     # poor performance on Mac OS X: http://bugs.python.org/issue4194
     p = subprocess.Popen(
         tonativestr(cmd),
         shell=True,
         bufsize=-1,
         close_fds=closefds,
         stdin=subprocess.PIPE,
         stdout=subprocess.PIPE,
         env=tonativeenv(env),
     )
     return p.stdin, p.stdout
 
 
 def popen3(cmd, env=None):
     stdin, stdout, stderr, p = popen4(cmd, env)
     return stdin, stdout, stderr
 
 
 def popen4(cmd, env=None, bufsize=-1):
     p = subprocess.Popen(
         tonativestr(cmd),
         shell=True,
         bufsize=bufsize,
         close_fds=closefds,
         stdin=subprocess.PIPE,
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE,
         env=tonativeenv(env),
     )
     return p.stdin, p.stdout, p.stderr, p
 
 
 def pipefilter(s, cmd):
     '''filter string S through command CMD, returning its output'''
     p = subprocess.Popen(
         tonativestr(cmd),
         shell=True,
         close_fds=closefds,
         stdin=subprocess.PIPE,
         stdout=subprocess.PIPE,
     )
     pout, perr = p.communicate(s)
     return pout
 
 
 def tempfilter(s, cmd):
     '''filter string S through a pair of temporary files with CMD.
     CMD is used as a template to create the real command to be run,
     with the strings INFILE and OUTFILE replaced by the real names of
     the temporary files generated.'''
     inname, outname = None, None
     try:
         infd, inname = pycompat.mkstemp(prefix=b'hg-filter-in-')
         fp = os.fdopen(infd, 'wb')
         fp.write(s)
         fp.close()
         outfd, outname = pycompat.mkstemp(prefix=b'hg-filter-out-')
         os.close(outfd)
         cmd = cmd.replace(b'INFILE', inname)
         cmd = cmd.replace(b'OUTFILE', outname)
         code = system(cmd)
         if pycompat.sysplatform == b'OpenVMS' and code & 1:
             code = 0
         if code:
             raise error.Abort(
                 _(b"command '%s' failed: %s") % (cmd, explainexit(code))
             )
         with open(outname, b'rb') as fp:
             return fp.read()
     finally:
         try:
             if inname:
                 os.unlink(inname)
         except OSError:
             pass
         try:
             if outname:
                 os.unlink(outname)
         except OSError:
             pass
 
 
 _filtertable = {
     b'tempfile:': tempfilter,
     b'pipe:': pipefilter,
 }
 
 
 def filter(s, cmd):
     """filter a string through a command that transforms its input to its
     output"""
     for name, fn in pycompat.iteritems(_filtertable):
         if cmd.startswith(name):
             return fn(s, cmd[len(name) :].lstrip())
     return pipefilter(s, cmd)
 
 
 _hgexecutable = None
 
 
 def hgexecutable():
     """return location of the 'hg' executable.
 
     Defaults to $HG or 'hg' in the search path.
     """
     if _hgexecutable is None:
         hg = encoding.environ.get(b'HG')
         mainmod = sys.modules['__main__']
         if hg:
             _sethgexecutable(hg)
         elif resourceutil.mainfrozen():
             if getattr(sys, 'frozen', None) == 'macosx_app':
                 # Env variable set by py2app
                 _sethgexecutable(encoding.environ[b'EXECUTABLEPATH'])
             else:
                 _sethgexecutable(pycompat.sysexecutable)
         elif (
             not pycompat.iswindows
             and os.path.basename(getattr(mainmod, '__file__', '')) == 'hg'
         ):
             _sethgexecutable(pycompat.fsencode(mainmod.__file__))
         else:
             _sethgexecutable(
                 findexe(b'hg') or os.path.basename(pycompat.sysargv[0])
             )
     return _hgexecutable
 
 
 def _sethgexecutable(path):
     """set location of the 'hg' executable"""
     global _hgexecutable
     _hgexecutable = path
 
 
 def _testfileno(f, stdf):
     fileno = getattr(f, 'fileno', None)
     try:
         return fileno and fileno() == stdf.fileno()
     except io.UnsupportedOperation:
         return False  # fileno() raised UnsupportedOperation
 
 
 def isstdin(f):
     return _testfileno(f, sys.__stdin__)
 
 
 def isstdout(f):
     return _testfileno(f, sys.__stdout__)
 
 
 def protectstdio(uin, uout):
     """Duplicate streams and redirect original if (uin, uout) are stdio
 
     If uin is stdin, it's redirected to /dev/null. If uout is stdout, it's
     redirected to stderr so the output is still readable.
 
     Returns (fin, fout) which point to the original (uin, uout) fds, but
     may be copy of (uin, uout). The returned streams can be considered
     "owned" in that print(), exec(), etc. never reach to them.
     """
     uout.flush()
     fin, fout = uin, uout
     if _testfileno(uin, stdin):
         newfd = os.dup(uin.fileno())
         nullfd = os.open(os.devnull, os.O_RDONLY)
         os.dup2(nullfd, uin.fileno())
         os.close(nullfd)
         fin = os.fdopen(newfd, 'rb')
     if _testfileno(uout, stdout):
         newfd = os.dup(uout.fileno())
         os.dup2(stderr.fileno(), uout.fileno())
         fout = os.fdopen(newfd, 'wb')
     return fin, fout
 
 
 def restorestdio(uin, uout, fin, fout):
     """Restore (uin, uout) streams from possibly duplicated (fin, fout)"""
     uout.flush()
     for f, uif in [(fin, uin), (fout, uout)]:
         if f is not uif:
             os.dup2(f.fileno(), uif.fileno())
             f.close()
 
 
 def shellenviron(environ=None):
     """return environ with optional override, useful for shelling out"""
 
     def py2shell(val):
         """convert python object into string that is useful to shell"""
         if val is None or val is False:
             return b'0'
         if val is True:
             return b'1'
         return pycompat.bytestr(val)
 
     env = dict(encoding.environ)
     if environ:
         env.update((k, py2shell(v)) for k, v in pycompat.iteritems(environ))
     env[b'HG'] = hgexecutable()
     return env
 
 
 if pycompat.iswindows:
 
     def shelltonative(cmd, env):
         return platform.shelltocmdexe(  # pytype: disable=module-attr
             cmd, shellenviron(env)
         )
 
     tonativestr = encoding.strfromlocal
 else:
 
     def shelltonative(cmd, env):
         return cmd
 
     tonativestr = pycompat.identity
 
 
 def tonativeenv(env):
     '''convert the environment from bytes to strings suitable for Popen(), etc.
     '''
     return pycompat.rapply(tonativestr, env)
 
 
 def system(cmd, environ=None, cwd=None, out=None):
     '''enhanced shell command execution.
     run with environment maybe modified, maybe in different dir.
 
     if out is specified, it is assumed to be a file-like object that has a
     write() method. stdout and stderr will be redirected to out.'''
     try:
         stdout.flush()
     except Exception:
         pass
     env = shellenviron(environ)
     if out is None or isstdout(out):
         rc = subprocess.call(
             tonativestr(cmd),
             shell=True,
             close_fds=closefds,
             env=tonativeenv(env),
             cwd=pycompat.rapply(tonativestr, cwd),
         )
     else:
         proc = subprocess.Popen(
             tonativestr(cmd),
             shell=True,
             close_fds=closefds,
             env=tonativeenv(env),
             cwd=pycompat.rapply(tonativestr, cwd),
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
         )
         for line in iter(proc.stdout.readline, b''):
             out.write(line)
         proc.wait()
         rc = proc.returncode
     if pycompat.sysplatform == b'OpenVMS' and rc & 1:
         rc = 0
     return rc
 
 
 _is_gui = None
 
 
 def _gui():
     '''Are we running in a GUI?'''
     if pycompat.isdarwin:
         if b'SSH_CONNECTION' in encoding.environ:
             # handle SSH access to a box where the user is logged in
             return False
         elif getattr(osutil, 'isgui', None):
             # check if a CoreGraphics session is available
             return osutil.isgui()
         else:
             # pure build; use a safe default
             return True
     else:
         return pycompat.iswindows or encoding.environ.get(b"DISPLAY")
 
 
 def gui():
     global _is_gui
     if _is_gui is None:
         _is_gui = _gui()
     return _is_gui
 
 
 def hgcmd():
     """Return the command used to execute current hg
 
     This is different from hgexecutable() because on Windows we want
     to avoid things opening new shell windows like batch files, so we
     get either the python call or current executable.
     """
     if resourceutil.mainfrozen():
         if getattr(sys, 'frozen', None) == 'macosx_app':
             # Env variable set by py2app
             return [encoding.environ[b'EXECUTABLEPATH']]
         else:
             return [pycompat.sysexecutable]
     return _gethgcmd()
 
 
 def rundetached(args, condfn):
     """Execute the argument list in a detached process.
 
     condfn is a callable which is called repeatedly and should return
     True once the child process is known to have started successfully.
     At this point, the child process PID is returned. If the child
     process fails to start or finishes before condfn() evaluates to
     True, return -1.
     """
     # Windows case is easier because the child process is either
     # successfully starting and validating the condition or exiting
     # on failure. We just poll on its PID. On Unix, if the child
     # process fails to start, it will be left in a zombie state until
     # the parent wait on it, which we cannot do since we expect a long
     # running process on success. Instead we listen for SIGCHLD telling
     # us our child process terminated.
     terminated = set()
 
     def handler(signum, frame):
         terminated.add(os.wait())
 
     prevhandler = None
     SIGCHLD = getattr(signal, 'SIGCHLD', None)
     if SIGCHLD is not None:
         prevhandler = signal.signal(SIGCHLD, handler)
     try:
         pid = spawndetached(args)
         while not condfn():
             if (pid in terminated or not testpid(pid)) and not condfn():
                 return -1
             time.sleep(0.1)
         return pid
     finally:
         if prevhandler is not None:
             signal.signal(signal.SIGCHLD, prevhandler)
 
 
 @contextlib.contextmanager
 def uninterruptible(warn):
     """Inhibit SIGINT handling on a region of code.
 
     Note that if this is called in a non-main thread, it turns into a no-op.
 
     Args:
       warn: A callable which takes no arguments, and returns True if the
             previous signal handling should be restored.
     """
 
     oldsiginthandler = [signal.getsignal(signal.SIGINT)]
     shouldbail = []
 
     def disabledsiginthandler(*args):
         if warn():
             signal.signal(signal.SIGINT, oldsiginthandler[0])
             del oldsiginthandler[0]
         shouldbail.append(True)
 
     try:
         try:
             signal.signal(signal.SIGINT, disabledsiginthandler)
         except ValueError:
             # wrong thread, oh well, we tried
             del oldsiginthandler[0]
         yield
     finally:
         if oldsiginthandler:
             signal.signal(signal.SIGINT, oldsiginthandler[0])
         if shouldbail:
             raise KeyboardInterrupt
 
 
 if pycompat.iswindows:
     # no fork on Windows, but we can create a detached process
     # https://msdn.microsoft.com/en-us/library/windows/desktop/ms684863.aspx
     # No stdlib constant exists for this value
     DETACHED_PROCESS = 0x00000008
     # Following creation flags might create a console GUI window.
     # Using subprocess.CREATE_NEW_CONSOLE might helps.
     # See https://phab.mercurial-scm.org/D1701 for discussion
     _creationflags = (
         DETACHED_PROCESS
         | subprocess.CREATE_NEW_PROCESS_GROUP  # pytype: disable=module-attr
     )
 
     def runbgcommand(
         script,
         env,
         shell=False,
         stdout=None,
         stderr=None,
         ensurestart=True,
         record_wait=None,
     ):
         '''Spawn a command without waiting for it to finish.'''
         # we can't use close_fds *and* redirect stdin. I'm not sure that we
         # need to because the detached process has no console connection.
         p = subprocess.Popen(
             tonativestr(script),
             shell=shell,
             env=tonativeenv(env),
             close_fds=True,
             creationflags=_creationflags,
             stdout=stdout,
             stderr=stderr,
         )
         if record_wait is not None:
             record_wait(p.wait)
 
 
 else:
 
     def runbgcommand(
         cmd,
         env,
         shell=False,
         stdout=None,
         stderr=None,
         ensurestart=True,
         record_wait=None,
     ):
         '''Spawn a command without waiting for it to finish.
 
 
         When `record_wait` is not None, the spawned process will not be fully
         detached and the `record_wait` argument will be called with a the
         `Subprocess.wait` function for the spawned process.  This is mostly
         useful for developers that need to make sure the spawned process
         finished before a certain point. (eg: writing test)'''
         if pycompat.isdarwin:
             # avoid crash in CoreFoundation in case another thread
             # calls gui() while we're calling fork().
             gui()
 
         # double-fork to completely detach from the parent process
         # based on http://code.activestate.com/recipes/278731
         if record_wait is None:
             pid = os.fork()
             if pid:
                 if not ensurestart:
                     # Even though we're not waiting on the child process,
                     # we still must call waitpid() on it at some point so
                     # it's not a zombie/defunct. This is especially relevant for
                     # chg since the parent process won't die anytime soon.
                     # We use a thread to make the overhead tiny.
                     def _do_wait():
                         os.waitpid(pid, 0)
 
                     t = threading.Thread(target=_do_wait)
                     t.daemon = True
                     t.start()
                     return
                 # Parent process
                 (_pid, status) = os.waitpid(pid, 0)
                 if os.WIFEXITED(status):
                     returncode = os.WEXITSTATUS(status)
                 else:
                     returncode = -(os.WTERMSIG(status))
                 if returncode != 0:
                     # The child process's return code is 0 on success, an errno
                     # value on failure, or 255 if we don't have a valid errno
                     # value.
                     #
                     # (It would be slightly nicer to return the full exception info
                     # over a pipe as the subprocess module does.  For now it
                     # doesn't seem worth adding that complexity here, though.)
                     if returncode == 255:
                         returncode = errno.EINVAL
                     raise OSError(
                         returncode,
                         b'error running %r: %s'
                         % (cmd, os.strerror(returncode)),
                     )
                 return
 
         returncode = 255
         try:
             if record_wait is None:
                 # Start a new session
                 os.setsid()
 
             stdin = open(os.devnull, b'r')
             if stdout is None:
                 stdout = open(os.devnull, b'w')
             if stderr is None:
                 stderr = open(os.devnull, b'w')
 
             # connect stdin to devnull to make sure the subprocess can't
             # muck up that stream for mercurial.
             p = subprocess.Popen(
                 cmd,
                 shell=shell,
                 env=env,
                 close_fds=True,
                 stdin=stdin,
                 stdout=stdout,
                 stderr=stderr,
             )
             if record_wait is not None:
                 record_wait(p.wait)
             returncode = 0
         except EnvironmentError as ex:
             returncode = ex.errno & 0xFF
             if returncode == 0:
                 # This shouldn't happen, but just in case make sure the
                 # return code is never 0 here.
                 returncode = 255
         except Exception:
             returncode = 255
         finally:
             # mission accomplished, this child needs to exit and not
             # continue the hg process here.
             if record_wait is None:
                 os._exit(returncode)

mercurial/windows.py

@@ -1,681 +1,685 b''
 # windows.py - Windows utility function implementations for Mercurial
 #
 #  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 import getpass
 import msvcrt
 import os
 import re
 import stat
 import string
 import sys
 
 from .i18n import _
 from .pycompat import getattr
 from . import (
     encoding,
     error,
     policy,
     pycompat,
     win32,
 )
 
 try:
     import _winreg as winreg  # pytype: disable=import-error
 
     winreg.CloseKey
 except ImportError:
     # py2 only
     import winreg  # pytype: disable=import-error
 
 osutil = policy.importmod('osutil')
 
 getfsmountpoint = win32.getvolumename
 getfstype = win32.getfstype
 getuser = win32.getuser
 hidewindow = win32.hidewindow
 makedir = win32.makedir
 nlinks = win32.nlinks
 oslink = win32.oslink
 samedevice = win32.samedevice
 samefile = win32.samefile
 setsignalhandler = win32.setsignalhandler
 spawndetached = win32.spawndetached
 split = os.path.split
 testpid = win32.testpid
 unlink = win32.unlink
 
 umask = 0o022
 
 
 class mixedfilemodewrapper(object):
     """Wraps a file handle when it is opened in read/write mode.
 
     fopen() and fdopen() on Windows have a specific-to-Windows requirement
     that files opened with mode r+, w+, or a+ make a call to a file positioning
     function when switching between reads and writes. Without this extra call,
     Python will raise a not very intuitive "IOError: [Errno 0] Error."
 
     This class wraps posixfile instances when the file is opened in read/write
     mode and automatically adds checks or inserts appropriate file positioning
     calls when necessary.
     """
 
     OPNONE = 0
     OPREAD = 1
     OPWRITE = 2
 
     def __init__(self, fp):
         object.__setattr__(self, '_fp', fp)
         object.__setattr__(self, '_lastop', 0)
 
     def __enter__(self):
         self._fp.__enter__()
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         self._fp.__exit__(exc_type, exc_val, exc_tb)
 
     def __getattr__(self, name):
         return getattr(self._fp, name)
 
     def __setattr__(self, name, value):
         return self._fp.__setattr__(name, value)
 
     def _noopseek(self):
         self._fp.seek(0, os.SEEK_CUR)
 
     def seek(self, *args, **kwargs):
         object.__setattr__(self, '_lastop', self.OPNONE)
         return self._fp.seek(*args, **kwargs)
 
     def write(self, d):
         if self._lastop == self.OPREAD:
             self._noopseek()
 
         object.__setattr__(self, '_lastop', self.OPWRITE)
         return self._fp.write(d)
 
     def writelines(self, *args, **kwargs):
         if self._lastop == self.OPREAD:
             self._noopeseek()
 
         object.__setattr__(self, '_lastop', self.OPWRITE)
         return self._fp.writelines(*args, **kwargs)
 
     def read(self, *args, **kwargs):
         if self._lastop == self.OPWRITE:
             self._noopseek()
 
         object.__setattr__(self, '_lastop', self.OPREAD)
         return self._fp.read(*args, **kwargs)
 
     def readline(self, *args, **kwargs):
         if self._lastop == self.OPWRITE:
             self._noopseek()
 
         object.__setattr__(self, '_lastop', self.OPREAD)
         return self._fp.readline(*args, **kwargs)
 
     def readlines(self, *args, **kwargs):
         if self._lastop == self.OPWRITE:
             self._noopseek()
 
         object.__setattr__(self, '_lastop', self.OPREAD)
         return self._fp.readlines(*args, **kwargs)
 
 
 class fdproxy(object):
     """Wraps osutil.posixfile() to override the name attribute to reflect the
     underlying file name.
     """
 
     def __init__(self, name, fp):
         self.name = name
         self._fp = fp
 
     def __enter__(self):
         self._fp.__enter__()
         # Return this wrapper for the context manager so that the name is
         # still available.
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         self._fp.__exit__(exc_type, exc_value, traceback)
 
     def __iter__(self):
         return iter(self._fp)
 
     def __getattr__(self, name):
         return getattr(self._fp, name)
 
 
 def posixfile(name, mode=b'r', buffering=-1):
     '''Open a file with even more POSIX-like semantics'''
     try:
         fp = osutil.posixfile(name, mode, buffering)  # may raise WindowsError
 
         # PyFile_FromFd() ignores the name, and seems to report fp.name as the
         # underlying file descriptor.
         if pycompat.ispy3:
             fp = fdproxy(name, fp)
 
         # The position when opening in append mode is implementation defined, so
         # make it consistent with other platforms, which position at EOF.
         if b'a' in mode:
             fp.seek(0, os.SEEK_END)
 
         if b'+' in mode:
             return mixedfilemodewrapper(fp)
 
         return fp
     except WindowsError as err:
         # convert to a friendlier exception
         raise IOError(
             err.errno, '%s: %s' % (encoding.strfromlocal(name), err.strerror)
         )
 
 
 # may be wrapped by win32mbcs extension
 listdir = osutil.listdir
 
 
 class winstdout(object):
     '''Some files on Windows misbehave.
 
     When writing to a broken pipe, EINVAL instead of EPIPE may be raised.
 
     When writing too many bytes to a console at the same, a "Not enough space"
     error may happen. Python 3 already works around that.
     '''
 
     def __init__(self, fp):
         self.fp = fp
+        self.throttle = not pycompat.ispy3 and fp.isatty()
 
     def __getattr__(self, key):
         return getattr(self.fp, key)
 
     def close(self):
         try:
             self.fp.close()
         except IOError:
             pass
 
     def write(self, s):
+        if not pycompat.ispy3:
+            self.softspace = 0
         try:
+            if not self.throttle:
+                return self.fp.write(s)
             # This is workaround for "Not enough space" error on
             # writing large size of data to console.
             limit = 16000
             l = len(s)
             start = 0
-            self.softspace = 0
             while start < l:
                 end = start + limit
                 self.fp.write(s[start:end])
                 start = end
         except IOError as inst:
             if inst.errno != 0 and not win32.lasterrorwaspipeerror(inst):
                 raise
             self.close()
             raise IOError(errno.EPIPE, 'Broken pipe')
 
     def flush(self):
         try:
             return self.fp.flush()
         except IOError as inst:
             if not win32.lasterrorwaspipeerror(inst):
                 raise
             raise IOError(errno.EPIPE, 'Broken pipe')
 
 
 def openhardlinks():
     return True
 
 
 def parsepatchoutput(output_line):
     """parses the output produced by patch and returns the filename"""
     pf = output_line[14:]
     if pf[0] == b'`':
         pf = pf[1:-1]  # Remove the quotes
     return pf
 
 
 def sshargs(sshcmd, host, user, port):
     '''Build argument list for ssh or Plink'''
     pflag = b'plink' in sshcmd.lower() and b'-P' or b'-p'
     args = user and (b"%s@%s" % (user, host)) or host
     if args.startswith(b'-') or args.startswith(b'/'):
         raise error.Abort(
             _(b'illegal ssh hostname or username starting with - or /: %s')
             % args
         )
     args = shellquote(args)
     if port:
         args = b'%s %s %s' % (pflag, shellquote(port), args)
     return args
 
 
 def setflags(f, l, x):
     pass
 
 
 def copymode(src, dst, mode=None, enforcewritable=False):
     pass
 
 
 def checkexec(path):
     return False
 
 
 def checklink(path):
     return False
 
 
 def setbinary(fd):
     # When run without console, pipes may expose invalid
     # fileno(), usually set to -1.
     fno = getattr(fd, 'fileno', None)
     if fno is not None and fno() >= 0:
         msvcrt.setmode(fno(), os.O_BINARY)  # pytype: disable=module-attr
 
 
 def pconvert(path):
     return path.replace(pycompat.ossep, b'/')
 
 
 def localpath(path):
     return path.replace(b'/', b'\\')
 
 
 def normpath(path):
     return pconvert(os.path.normpath(path))
 
 
 def normcase(path):
     return encoding.upper(path)  # NTFS compares via upper()
 
 
 # see posix.py for definitions
 normcasespec = encoding.normcasespecs.upper
 normcasefallback = encoding.upperfallback
 
 
 def samestat(s1, s2):
     return False
 
 
 def shelltocmdexe(path, env):
     r"""Convert shell variables in the form $var and ${var} inside ``path``
     to %var% form.  Existing Windows style variables are left unchanged.
 
     The variables are limited to the given environment.  Unknown variables are
     left unchanged.
 
     >>> e = {b'var1': b'v1', b'var2': b'v2', b'var3': b'v3'}
     >>> # Only valid values are expanded
     >>> shelltocmdexe(b'cmd $var1 ${var2} %var3% $missing ${missing} %missing%',
     ...               e)
     'cmd %var1% %var2% %var3% $missing ${missing} %missing%'
     >>> # Single quote prevents expansion, as does \$ escaping
     >>> shelltocmdexe(b"cmd '$var1 ${var2} %var3%' \$var1 \${var2} \\", e)
     'cmd "$var1 ${var2} %var3%" $var1 ${var2} \\'
     >>> # $$ is not special. %% is not special either, but can be the end and
     >>> # start of consecutive variables
     >>> shelltocmdexe(b"cmd $$ %% %var1%%var2%", e)
     'cmd $$ %% %var1%%var2%'
     >>> # No double substitution
     >>> shelltocmdexe(b"$var1 %var1%", {b'var1': b'%var2%', b'var2': b'boom'})
     '%var1% %var1%'
     >>> # Tilde expansion
     >>> shelltocmdexe(b"~/dir ~\dir2 ~tmpfile \~/", {})
     '%USERPROFILE%/dir %USERPROFILE%\\dir2 ~tmpfile ~/'
     """
     if not any(c in path for c in b"$'~"):
         return path
 
     varchars = pycompat.sysbytes(string.ascii_letters + string.digits) + b'_-'
 
     res = b''
     index = 0
     pathlen = len(path)
     while index < pathlen:
         c = path[index : index + 1]
         if c == b'\'':  # no expansion within single quotes
             path = path[index + 1 :]
             pathlen = len(path)
             try:
                 index = path.index(b'\'')
                 res += b'"' + path[:index] + b'"'
             except ValueError:
                 res += c + path
                 index = pathlen - 1
         elif c == b'%':  # variable
             path = path[index + 1 :]
             pathlen = len(path)
             try:
                 index = path.index(b'%')
             except ValueError:
                 res += b'%' + path
                 index = pathlen - 1
             else:
                 var = path[:index]
                 res += b'%' + var + b'%'
         elif c == b'$':  # variable
             if path[index + 1 : index + 2] == b'{':
                 path = path[index + 2 :]
                 pathlen = len(path)
                 try:
                     index = path.index(b'}')
                     var = path[:index]
 
                     # See below for why empty variables are handled specially
                     if env.get(var, b'') != b'':
                         res += b'%' + var + b'%'
                     else:
                         res += b'${' + var + b'}'
                 except ValueError:
                     res += b'${' + path
                     index = pathlen - 1
             else:
                 var = b''
                 index += 1
                 c = path[index : index + 1]
                 while c != b'' and c in varchars:
                     var += c
                     index += 1
                     c = path[index : index + 1]
                 # Some variables (like HG_OLDNODE) may be defined, but have an
                 # empty value.  Those need to be skipped because when spawning
                 # cmd.exe to run the hook, it doesn't replace %VAR% for an empty
                 # VAR, and that really confuses things like revset expressions.
                 # OTOH, if it's left in Unix format and the hook runs sh.exe, it
                 # will substitute to an empty string, and everything is happy.
                 if env.get(var, b'') != b'':
                     res += b'%' + var + b'%'
                 else:
                     res += b'$' + var
 
                 if c != b'':
                     index -= 1
         elif (
             c == b'~'
             and index + 1 < pathlen
             and path[index + 1 : index + 2] in (b'\\', b'/')
         ):
             res += b"%USERPROFILE%"
         elif (
             c == b'\\'
             and index + 1 < pathlen
             and path[index + 1 : index + 2] in (b'$', b'~')
         ):
             # Skip '\', but only if it is escaping $ or ~
             res += path[index + 1 : index + 2]
             index += 1
         else:
             res += c
 
         index += 1
     return res
 
 
 # A sequence of backslashes is special iff it precedes a double quote:
 # - if there's an even number of backslashes, the double quote is not
 #   quoted (i.e. it ends the quoted region)
 # - if there's an odd number of backslashes, the double quote is quoted
 # - in both cases, every pair of backslashes is unquoted into a single
 #   backslash
 # (See http://msdn2.microsoft.com/en-us/library/a1y7w461.aspx )
 # So, to quote a string, we must surround it in double quotes, double
 # the number of backslashes that precede double quotes and add another
 # backslash before every double quote (being careful with the double
 # quote we've appended to the end)
 _quotere = None
 _needsshellquote = None
 
 
 def shellquote(s):
     r"""
     >>> shellquote(br'C:\Users\xyz')
     '"C:\\Users\\xyz"'
     >>> shellquote(br'C:\Users\xyz/mixed')
     '"C:\\Users\\xyz/mixed"'
     >>> # Would be safe not to quote too, since it is all double backslashes
     >>> shellquote(br'C:\\Users\\xyz')
     '"C:\\\\Users\\\\xyz"'
     >>> # But this must be quoted
     >>> shellquote(br'C:\\Users\\xyz/abc')
     '"C:\\\\Users\\\\xyz/abc"'
     """
     global _quotere
     if _quotere is None:
         _quotere = re.compile(br'(\\*)("|\\$)')
     global _needsshellquote
     if _needsshellquote is None:
         # ":" is also treated as "safe character", because it is used as a part
         # of path name on Windows.  "\" is also part of a path name, but isn't
         # safe because shlex.split() (kind of) treats it as an escape char and
         # drops it.  It will leave the next character, even if it is another
         # "\".
         _needsshellquote = re.compile(br'[^a-zA-Z0-9._:/-]').search
     if s and not _needsshellquote(s) and not _quotere.search(s):
         # "s" shouldn't have to be quoted
         return s
     return b'"%s"' % _quotere.sub(br'\1\1\\\2', s)
 
 
 def _unquote(s):
     if s.startswith(b'"') and s.endswith(b'"'):
         return s[1:-1]
     return s
 
 
 def shellsplit(s):
     """Parse a command string in cmd.exe way (best-effort)"""
     return pycompat.maplist(_unquote, pycompat.shlexsplit(s, posix=False))
 
 
 # if you change this stub into a real check, please try to implement the
 # username and groupname functions above, too.
 def isowner(st):
     return True
 
 
 def findexe(command):
     '''Find executable for command searching like cmd.exe does.
     If command is a basename then PATH is searched for command.
     PATH isn't searched if command is an absolute or relative path.
     An extension from PATHEXT is found and added if not present.
     If command isn't found None is returned.'''
     pathext = encoding.environ.get(b'PATHEXT', b'.COM;.EXE;.BAT;.CMD')
     pathexts = [ext for ext in pathext.lower().split(pycompat.ospathsep)]
     if os.path.splitext(command)[1].lower() in pathexts:
         pathexts = [b'']
 
     def findexisting(pathcommand):
         """Will append extension (if needed) and return existing file"""
         for ext in pathexts:
             executable = pathcommand + ext
             if os.path.exists(executable):
                 return executable
         return None
 
     if pycompat.ossep in command:
         return findexisting(command)
 
     for path in encoding.environ.get(b'PATH', b'').split(pycompat.ospathsep):
         executable = findexisting(os.path.join(path, command))
         if executable is not None:
             return executable
     return findexisting(os.path.expanduser(os.path.expandvars(command)))
 
 
 _wantedkinds = {stat.S_IFREG, stat.S_IFLNK}
 
 
 def statfiles(files):
     '''Stat each file in files. Yield each stat, or None if a file
     does not exist or has a type we don't care about.
 
     Cluster and cache stat per directory to minimize number of OS stat calls.'''
     dircache = {}  # dirname -> filename -> status | None if file does not exist
     getkind = stat.S_IFMT
     for nf in files:
         nf = normcase(nf)
         dir, base = os.path.split(nf)
         if not dir:
             dir = b'.'
         cache = dircache.get(dir, None)
         if cache is None:
             try:
                 dmap = {
                     normcase(n): s
                     for n, k, s in listdir(dir, True)
                     if getkind(s.st_mode) in _wantedkinds
                 }
             except OSError as err:
                 # Python >= 2.5 returns ENOENT and adds winerror field
                 # EINVAL is raised if dir is not a directory.
                 if err.errno not in (errno.ENOENT, errno.EINVAL, errno.ENOTDIR):
                     raise
                 dmap = {}
             cache = dircache.setdefault(dir, dmap)
         yield cache.get(base, None)
 
 
 def username(uid=None):
     """Return the name of the user with the given uid.
 
     If uid is None, return the name of the current user."""
     if not uid:
         return pycompat.fsencode(getpass.getuser())
     return None
 
 
 def groupname(gid=None):
     """Return the name of the group with the given gid.
 
     If gid is None, return the name of the current group."""
     return None
 
 
 def readlink(pathname):
     return pycompat.fsencode(os.readlink(pycompat.fsdecode(pathname)))
 
 
 def removedirs(name):
     """special version of os.removedirs that does not remove symlinked
     directories or junction points if they actually contain files"""
     if listdir(name):
         return
     os.rmdir(name)
     head, tail = os.path.split(name)
     if not tail:
         head, tail = os.path.split(head)
     while head and tail:
         try:
             if listdir(head):
                 return
             os.rmdir(head)
         except (ValueError, OSError):
             break
         head, tail = os.path.split(head)
 
 
 def rename(src, dst):
     '''atomically rename file src to dst, replacing dst if it exists'''
     try:
         os.rename(src, dst)
     except OSError as e:
         if e.errno != errno.EEXIST:
             raise
         unlink(dst)
         os.rename(src, dst)
 
 
 def gethgcmd():
     return [encoding.strtolocal(arg) for arg in [sys.executable] + sys.argv[:1]]
 
 
 def groupmembers(name):
     # Don't support groups on Windows for now
     raise KeyError
 
 
 def isexec(f):
     return False
 
 
 class cachestat(object):
     def __init__(self, path):
         pass
 
     def cacheable(self):
         return False
 
 
 def lookupreg(key, valname=None, scope=None):
     ''' Look up a key/value name in the Windows registry.
 
     valname: value name. If unspecified, the default value for the key
     is used.
     scope: optionally specify scope for registry lookup, this can be
     a sequence of scopes to look up in order. Default (CURRENT_USER,
     LOCAL_MACHINE).
     '''
     if scope is None:
         scope = (winreg.HKEY_CURRENT_USER, winreg.HKEY_LOCAL_MACHINE)
     elif not isinstance(scope, (list, tuple)):
         scope = (scope,)
     for s in scope:
         try:
             with winreg.OpenKey(s, encoding.strfromlocal(key)) as hkey:
                 name = valname and encoding.strfromlocal(valname) or valname
                 val = winreg.QueryValueEx(hkey, name)[0]
                 # never let a Unicode string escape into the wild
                 return encoding.unitolocal(val)
         except EnvironmentError:
             pass
 
 
 expandglobs = True
 
 
 def statislink(st):
     '''check whether a stat result is a symlink'''
     return False
 
 
 def statisexec(st):
     '''check whether a stat result is an executable file'''
     return False
 
 
 def poll(fds):
     # see posix.py for description
     raise NotImplementedError()
 
 
 def readpipe(pipe):
     """Read all available data from a pipe."""
     chunks = []
     while True:
         size = win32.peekpipe(pipe)
         if not size:
             break
 
         s = pipe.read(size)
         if not s:
             break
         chunks.append(s)
 
     return b''.join(chunks)
 
 
 def bindunixsocket(sock, path):
     raise NotImplementedError('unsupported platform')

tests/test-stdio.py

@@ -1,302 +1,365 b''
 #!/usr/bin/env python
 """
 Tests the buffering behavior of stdio streams in `mercurial.utils.procutil`.
 """
 from __future__ import absolute_import
 
 import contextlib
 import errno
 import os
 import signal
 import subprocess
 import sys
 import tempfile
 import unittest
 
-from mercurial import pycompat
+from mercurial import pycompat, util
 
 
 if pycompat.ispy3:
 
     def set_noninheritable(fd):
         # On Python 3, file descriptors are non-inheritable by default.
         pass
 
 
 else:
     if pycompat.iswindows:
         # unused
         set_noninheritable = None
     else:
         import fcntl
 
         def set_noninheritable(fd):
             old = fcntl.fcntl(fd, fcntl.F_GETFD)
             fcntl.fcntl(fd, fcntl.F_SETFD, old | fcntl.FD_CLOEXEC)
 
 
 TEST_BUFFERING_CHILD_SCRIPT = r'''
 import os
 
 from mercurial import dispatch
 from mercurial.utils import procutil
 
 dispatch.initstdio()
 procutil.{stream}.write(b'aaa')
 os.write(procutil.{stream}.fileno(), b'[written aaa]')
 procutil.{stream}.write(b'bbb\n')
 os.write(procutil.{stream}.fileno(), b'[written bbb\\n]')
 '''
 UNBUFFERED = b'aaa[written aaa]bbb\n[written bbb\\n]'
 LINE_BUFFERED = b'[written aaa]aaabbb\n[written bbb\\n]'
 FULLY_BUFFERED = b'[written aaa][written bbb\\n]aaabbb\n'
 
 
 TEST_LARGE_WRITE_CHILD_SCRIPT = r'''
 import os
 import signal
 import sys
 
 from mercurial import dispatch
 from mercurial.utils import procutil
 
 signal.signal(signal.SIGINT, lambda *x: None)
 dispatch.initstdio()
 write_result = procutil.{stream}.write(b'x' * 1048576)
 with os.fdopen(
     os.open({write_result_fn!r}, os.O_WRONLY | getattr(os, 'O_TEMPORARY', 0)),
     'w',
 ) as write_result_f:
     write_result_f.write(str(write_result))
 '''
 
 
+TEST_BROKEN_PIPE_CHILD_SCRIPT = r'''
+import os
+import pickle
+
+from mercurial import dispatch
+from mercurial.utils import procutil
+
+dispatch.initstdio()
+procutil.stdin.read(1)  # wait until parent process closed pipe
+try:
+    procutil.{stream}.write(b'test')
+    procutil.{stream}.flush()
+except EnvironmentError as e:
+    with os.fdopen(
+        os.open(
+            {err_fn!r},
+            os.O_WRONLY
+            | getattr(os, 'O_BINARY', 0)
+            | getattr(os, 'O_TEMPORARY', 0),
+        ),
+        'wb',
+    ) as err_f:
+        pickle.dump(e, err_f)
+# Exit early to suppress further broken pipe errors at interpreter shutdown.
+os._exit(0)
+'''
+
+
 @contextlib.contextmanager
 def _closing(fds):
     try:
         yield
     finally:
         for fd in fds:
             try:
                 os.close(fd)
             except EnvironmentError:
                 pass
 
 
 # In the following, we set the FDs non-inheritable mainly to make it possible
 # for tests to close the receiving end of the pipe / PTYs.
 
 
 @contextlib.contextmanager
 def _devnull():
     devnull = os.open(os.devnull, os.O_WRONLY)
     # We don't have a receiving end, so it's not worth the effort on Python 2
     # on Windows to make the FD non-inheritable.
     with _closing([devnull]):
         yield (None, devnull)
 
 
 @contextlib.contextmanager
 def _pipes():
     rwpair = os.pipe()
     # Pipes are already non-inheritable on Windows.
     if not pycompat.iswindows:
         set_noninheritable(rwpair[0])
         set_noninheritable(rwpair[1])
     with _closing(rwpair):
         yield rwpair
 
 
 @contextlib.contextmanager
 def _ptys():
     if pycompat.iswindows:
         raise unittest.SkipTest("PTYs are not supported on Windows")
     import pty
     import tty
 
     rwpair = pty.openpty()
     set_noninheritable(rwpair[0])
     set_noninheritable(rwpair[1])
     with _closing(rwpair):
         tty.setraw(rwpair[0])
         yield rwpair
 
 
 def _readall(fd, buffer_size, initial_buf=None):
     buf = initial_buf or []
     while True:
         try:
             s = os.read(fd, buffer_size)
         except OSError as e:
             if e.errno == errno.EIO:
                 # If the child-facing PTY got closed, reading from the
                 # parent-facing PTY raises EIO.
                 break
             raise
         if not s:
             break
         buf.append(s)
     return b''.join(buf)
 
 
 class TestStdio(unittest.TestCase):
     def _test(
         self,
         child_script,
         stream,
         rwpair_generator,
         check_output,
         python_args=[],
         post_child_check=None,
+        stdin_generator=None,
     ):
         assert stream in ('stdout', 'stderr')
-        with rwpair_generator() as (stream_receiver, child_stream), open(
-            os.devnull, 'rb'
-        ) as child_stdin:
+        if stdin_generator is None:
+            stdin_generator = open(os.devnull, 'rb')
+        with rwpair_generator() as (
+            stream_receiver,
+            child_stream,
+        ), stdin_generator as child_stdin:
             proc = subprocess.Popen(
                 [sys.executable] + python_args + ['-c', child_script],
                 stdin=child_stdin,
                 stdout=child_stream if stream == 'stdout' else None,
                 stderr=child_stream if stream == 'stderr' else None,
             )
             try:
                 os.close(child_stream)
                 if stream_receiver is not None:
                     check_output(stream_receiver, proc)
             except:  # re-raises
                 proc.terminate()
                 raise
             finally:
                 retcode = proc.wait()
             self.assertEqual(retcode, 0)
             if post_child_check is not None:
                 post_child_check()
 
     def _test_buffering(
         self, stream, rwpair_generator, expected_output, python_args=[]
     ):
         def check_output(stream_receiver, proc):
             self.assertEqual(_readall(stream_receiver, 1024), expected_output)
 
         self._test(
             TEST_BUFFERING_CHILD_SCRIPT.format(stream=stream),
             stream,
             rwpair_generator,
             check_output,
             python_args,
         )
 
     def test_buffering_stdout_devnull(self):
         self._test_buffering('stdout', _devnull, None)
 
     def test_buffering_stdout_pipes(self):
         self._test_buffering('stdout', _pipes, FULLY_BUFFERED)
 
     def test_buffering_stdout_ptys(self):
         self._test_buffering('stdout', _ptys, LINE_BUFFERED)
 
     def test_buffering_stdout_devnull_unbuffered(self):
         self._test_buffering('stdout', _devnull, None, python_args=['-u'])
 
     def test_buffering_stdout_pipes_unbuffered(self):
         self._test_buffering('stdout', _pipes, UNBUFFERED, python_args=['-u'])
 
     def test_buffering_stdout_ptys_unbuffered(self):
         self._test_buffering('stdout', _ptys, UNBUFFERED, python_args=['-u'])
 
     if not pycompat.ispy3 and not pycompat.iswindows:
         # On Python 2 on non-Windows, we manually open stdout in line-buffered
         # mode if connected to a TTY. We should check if Python was configured
         # to use unbuffered stdout, but it's hard to do that.
         test_buffering_stdout_ptys_unbuffered = unittest.expectedFailure(
             test_buffering_stdout_ptys_unbuffered
         )
 
     def _test_large_write(self, stream, rwpair_generator, python_args=[]):
         if not pycompat.ispy3 and pycompat.isdarwin:
             # Python 2 doesn't always retry on EINTR, but the libc might retry.
             # So far, it was observed only on macOS that EINTR is raised at the
             # Python level. As Python 2 support will be dropped soon-ish, we
             # won't attempt to fix it.
             raise unittest.SkipTest("raises EINTR on macOS")
 
         def check_output(stream_receiver, proc):
             if not pycompat.iswindows:
                 # On Unix, we can provoke a partial write() by interrupting it
                 # by a signal handler as soon as a bit of data was written.
                 # We test that write() is called until all data is written.
                 buf = [os.read(stream_receiver, 1)]
                 proc.send_signal(signal.SIGINT)
             else:
                 # On Windows, there doesn't seem to be a way to cause partial
                 # writes.
                 buf = []
             self.assertEqual(
                 _readall(stream_receiver, 131072, buf), b'x' * 1048576
             )
 
         def post_child_check():
             write_result_str = write_result_f.read()
             if pycompat.ispy3:
                 # On Python 3, we test that the correct number of bytes is
                 # claimed to have been written.
                 expected_write_result_str = '1048576'
             else:
                 # On Python 2, we only check that the large write does not
                 # crash.
                 expected_write_result_str = 'None'
             self.assertEqual(write_result_str, expected_write_result_str)
 
         with tempfile.NamedTemporaryFile('r') as write_result_f:
             self._test(
                 TEST_LARGE_WRITE_CHILD_SCRIPT.format(
                     stream=stream, write_result_fn=write_result_f.name
                 ),
                 stream,
                 rwpair_generator,
                 check_output,
                 python_args,
                 post_child_check=post_child_check,
             )
 
     def test_large_write_stdout_devnull(self):
         self._test_large_write('stdout', _devnull)
 
     def test_large_write_stdout_pipes(self):
         self._test_large_write('stdout', _pipes)
 
     def test_large_write_stdout_ptys(self):
         self._test_large_write('stdout', _ptys)
 
     def test_large_write_stdout_devnull_unbuffered(self):
         self._test_large_write('stdout', _devnull, python_args=['-u'])
 
     def test_large_write_stdout_pipes_unbuffered(self):
         self._test_large_write('stdout', _pipes, python_args=['-u'])
 
     def test_large_write_stdout_ptys_unbuffered(self):
         self._test_large_write('stdout', _ptys, python_args=['-u'])
 
     def test_large_write_stderr_devnull(self):
         self._test_large_write('stderr', _devnull)
 
     def test_large_write_stderr_pipes(self):
         self._test_large_write('stderr', _pipes)
 
     def test_large_write_stderr_ptys(self):
         self._test_large_write('stderr', _ptys)
 
     def test_large_write_stderr_devnull_unbuffered(self):
         self._test_large_write('stderr', _devnull, python_args=['-u'])
 
     def test_large_write_stderr_pipes_unbuffered(self):
         self._test_large_write('stderr', _pipes, python_args=['-u'])
 
     def test_large_write_stderr_ptys_unbuffered(self):
         self._test_large_write('stderr', _ptys, python_args=['-u'])
 
+    def _test_broken_pipe(self, stream):
+        assert stream in ('stdout', 'stderr')
+
+        def check_output(stream_receiver, proc):
+            os.close(stream_receiver)
+            proc.stdin.write(b'x')
+            proc.stdin.close()
+
+        def post_child_check():
+            err = util.pickle.load(err_f)
+            self.assertEqual(err.errno, errno.EPIPE)
+            self.assertEqual(err.strerror, "Broken pipe")
+
+        with tempfile.NamedTemporaryFile('rb') as err_f:
+            self._test(
+                TEST_BROKEN_PIPE_CHILD_SCRIPT.format(
+                    stream=stream, err_fn=err_f.name
+                ),
+                stream,
+                _pipes,
+                check_output,
+                post_child_check=post_child_check,
+                stdin_generator=util.nullcontextmanager(subprocess.PIPE),
+            )
+
+    def test_broken_pipe_stdout(self):
+        self._test_broken_pipe('stdout')
+
+    def test_broken_pipe_stderr(self):
+        self._test_broken_pipe('stderr')
+
 
 if __name__ == '__main__':
     import silenttestrunner
 
     silenttestrunner.main(__name__)