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.
# diffutil.py - utility functions related to diff and patch
#
# Copyright 2006 Brendan Cully <brendan@kublai.com>
# Copyright 2007 Chris Mason <chris.mason@oracle.com>
# Copyright 2018 Octobus <octobus@octobus.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from .i18n import _
from . import (
mdiff,
pycompat,
)
def diffallopts(
ui, opts=None, untrusted=False, section=b'diff', configprefix=b''
):
'''return diffopts with all features supported and parsed'''
return difffeatureopts(
ui,
opts=opts,
untrusted=untrusted,
section=section,
git=True,
whitespace=True,
formatchanging=True,
configprefix=configprefix,
)
def difffeatureopts(
ui,
opts=None,
untrusted=False,
section=b'diff',
git=False,
whitespace=False,
formatchanging=False,
configprefix=b'',
):
"""return diffopts with only opted-in features parsed
Features:
- git: git-style diffs
- whitespace: whitespace options like ignoreblanklines and ignorews
- formatchanging: options that will likely break or cause correctness issues
with most diff parsers
"""
def get(key, name=None, getter=ui.configbool, forceplain=None):
if opts:
v = opts.get(key)
# diffopts flags are either None-default (which is passed
# through unchanged, so we can identify unset values), or
# some other falsey default (eg --unified, which defaults
# to an empty string). We only want to override the config
# entries from hgrc with command line values if they
# appear to have been set, which is any truthy value,
# True, or False.
if v or isinstance(v, bool):
return v
if forceplain is not None and ui.plain():
return forceplain
return getter(
section, configprefix + (name or key), untrusted=untrusted
)
# core options, expected to be understood by every diff parser
buildopts = {
b'nodates': get(b'nodates'),
b'showfunc': get(b'show_function', b'showfunc'),
b'context': get(b'unified', getter=ui.config),
}
buildopts[b'xdiff'] = ui.configbool(b'experimental', b'xdiff')
if git:
buildopts[b'git'] = get(b'git')
# since this is in the experimental section, we need to call
# ui.configbool directory
buildopts[b'showsimilarity'] = ui.configbool(
b'experimental', b'extendedheader.similarity'
)
# need to inspect the ui object instead of using get() since we want to
# test for an int
hconf = ui.config(b'experimental', b'extendedheader.index')
if hconf is not None:
hlen = None
try:
# the hash config could be an integer (for length of hash) or a
# word (e.g. short, full, none)
hlen = int(hconf)
if hlen < 0 or hlen > 40:
msg = _(b"invalid length for extendedheader.index: '%d'\n")
ui.warn(msg % hlen)
except ValueError:
# default value
if hconf == b'short' or hconf == b'':
hlen = 12
elif hconf == b'full':
hlen = 40
elif hconf != b'none':
msg = _(b"invalid value for extendedheader.index: '%s'\n")
ui.warn(msg % hconf)
finally:
buildopts[b'index'] = hlen
if whitespace:
buildopts[b'ignorews'] = get(b'ignore_all_space', b'ignorews')
buildopts[b'ignorewsamount'] = get(
b'ignore_space_change', b'ignorewsamount'
)
buildopts[b'ignoreblanklines'] = get(
b'ignore_blank_lines', b'ignoreblanklines'
)
buildopts[b'ignorewseol'] = get(b'ignore_space_at_eol', b'ignorewseol')
if formatchanging:
buildopts[b'text'] = opts and opts.get(b'text')
binary = None if opts is None else opts.get(b'binary')
buildopts[b'nobinary'] = (
not binary
if binary is not None
else get(b'nobinary', forceplain=False)
)
buildopts[b'noprefix'] = get(b'noprefix', forceplain=False)
buildopts[b'worddiff'] = get(
b'word_diff', b'word-diff', forceplain=False
)
return mdiff.diffopts(**pycompat.strkwargs(buildopts))