procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
import os
from . import (
encoding,
pycompat,
util,
win32,
)
try:
import _winreg as winreg # pytype: disable=import-error
winreg.CloseKey
except ImportError:
# py2 only
import winreg # pytype: disable=import-error
# MS-DOS 'more' is the only pager available by default on Windows.
fallbackpager = b'more'
def systemrcpath():
'''return default os-specific hgrc search path'''
rcpath = []
filename = win32.executablepath()
# Use mercurial.ini found in directory with hg.exe
progrc = os.path.join(os.path.dirname(filename), b'mercurial.ini')
rcpath.append(progrc)
def _processdir(progrcd):
if os.path.isdir(progrcd):
for f, kind in sorted(util.listdir(progrcd)):
if f.endswith(b'.rc'):
rcpath.append(os.path.join(progrcd, f))
# Use hgrc.d found in directory with hg.exe
_processdir(os.path.join(os.path.dirname(filename), b'hgrc.d'))
# treat a PROGRAMDATA directory as equivalent to /etc/mercurial
programdata = encoding.environ.get(b'PROGRAMDATA')
if programdata:
programdata = os.path.join(programdata, b'Mercurial')
_processdir(os.path.join(programdata, b'hgrc.d'))
ini = os.path.join(programdata, b'mercurial.ini')
if os.path.isfile(ini):
rcpath.append(ini)
ini = os.path.join(programdata, b'hgrc')
if os.path.isfile(ini):
rcpath.append(ini)
# next look for a system rcpath in the registry
value = util.lookupreg(
# pytype: disable=module-attr
b'SOFTWARE\\Mercurial',
None,
winreg.HKEY_LOCAL_MACHINE
# pytype: enable=module-attr
)
if value and isinstance(value, bytes):
value = util.localpath(value)
for p in value.split(pycompat.ospathsep):
if p.lower().endswith(b'mercurial.ini'):
rcpath.append(p)
else:
_processdir(p)
return rcpath
def userrcpath():
'''return os-specific hgrc search path to the user dir'''
home = _legacy_expanduser(b'~')
path = [os.path.join(home, b'mercurial.ini'), os.path.join(home, b'.hgrc')]
userprofile = encoding.environ.get(b'USERPROFILE')
if userprofile and userprofile != home:
path.append(os.path.join(userprofile, b'mercurial.ini'))
path.append(os.path.join(userprofile, b'.hgrc'))
return path
def _legacy_expanduser(path):
"""Expand ~ and ~user constructs in the pre 3.8 style"""
# Python 3.8+ changed the expansion of '~' from HOME to USERPROFILE. See
# https://bugs.python.org/issue36264. It also seems to capitalize the drive
# letter, as though it was processed through os.path.realpath().
if not path.startswith(b'~'):
return path
i, n = 1, len(path)
while i < n and path[i] not in b'\\/':
i += 1
if b'HOME' in encoding.environ:
userhome = encoding.environ[b'HOME']
elif b'USERPROFILE' in encoding.environ:
userhome = encoding.environ[b'USERPROFILE']
elif b'HOMEPATH' not in encoding.environ:
return path
else:
try:
drive = encoding.environ[b'HOMEDRIVE']
except KeyError:
drive = b''
userhome = os.path.join(drive, encoding.environ[b'HOMEPATH'])
if i != 1: # ~user
userhome = os.path.join(os.path.dirname(userhome), path[1:i])
return userhome + path[i:]
def termsize(ui):
return win32.termsize()