view mercurial/scmposix.py @ 41218:24a1f67bb75a

revset: enforce "%d" to be interpreted as literal revision number (API) (BC)

Before this change, `formatspec("%d", x)` results in `"%d" % int(x)`. This
seems simple and correct until you consider `nullrev`. In revset, a direct
"-1" symbol is equivalent to `tip` not `nullrev`. This is a subtle error that
went undetected for a while. Wrapping the revision number inside 'rev()'
remove the ambiguity, preserving nullrev value passed to formatspec.

It got caught by the rebase code, were the following wrongly returned `[1]`:

    repo.revs("children(%d) and ancestors(%ld)", 0, [nullrev])

This is flagged as API, because `%d` can be used for non-revision integer
argument of revset function. We probably need to introduce a new '%…'
substitution to allow literal integer (maybe `%i`). However, the `%d` usage is
currently widespread for revision number so it is important to fix this issue
for `%d`.  This choice is reinforced by the fact _intlist is implemented as
revisions only. Restricting `%d` to revision only makes things more
consistent.

This bug can become especially tricky since `_intlist` recognize `nullrev`
right. So `revs('%ld', [-1, 0])` → select `[nullrev, 0]` but `revs('%ld',
[-1])` is simplified and treated as `%d` selecting `[tip]`.

Another side effect is that "%d" of an unknown revision simply match nothing. It
was previously raising and error. This is consistent with what "%ld" (and
`_intlist`) is doing, so it seems like a good move.

from __future__ import absolute_import

import array
import errno
import fcntl
import os
import sys

from . import (
    encoding,
    pycompat,
    util,
)

# BSD 'more' escapes ANSI color sequences by default. This can be disabled by
# $MORE variable, but there's no compatible option with Linux 'more'. Given
# OS X is widely used and most modern Unix systems would have 'less', setting
# 'less' as the default seems reasonable.
fallbackpager = 'less'

def _rcfiles(path):
    rcs = [os.path.join(path, 'hgrc')]
    rcdir = os.path.join(path, 'hgrc.d')
    try:
        rcs.extend([os.path.join(rcdir, f)
                    for f, kind in util.listdir(rcdir)
                    if f.endswith(".rc")])
    except OSError:
        pass
    return rcs

def systemrcpath():
    path = []
    if pycompat.sysplatform == 'plan9':
        root = 'lib/mercurial'
    else:
        root = 'etc/mercurial'
    # old mod_python does not set sys.argv
    if len(getattr(sys, 'argv', [])) > 0:
        p = os.path.dirname(os.path.dirname(pycompat.sysargv[0]))
        if p != '/':
            path.extend(_rcfiles(os.path.join(p, root)))
    path.extend(_rcfiles('/' + root))
    return path

def userrcpath():
    if pycompat.sysplatform == 'plan9':
        return [encoding.environ['home'] + '/lib/hgrc']
    elif pycompat.isdarwin:
        return [os.path.expanduser('~/.hgrc')]
    else:
        confighome = encoding.environ.get('XDG_CONFIG_HOME')
        if confighome is None or not os.path.isabs(confighome):
            confighome = os.path.expanduser('~/.config')

        return [os.path.expanduser('~/.hgrc'),
                os.path.join(confighome, 'hg', 'hgrc')]

def termsize(ui):
    try:
        import termios
        TIOCGWINSZ = termios.TIOCGWINSZ  # unavailable on IRIX (issue3449)
    except (AttributeError, ImportError):
        return 80, 24

    for dev in (ui.ferr, ui.fout, ui.fin):
        try:
            try:
                fd = dev.fileno()
            except AttributeError:
                continue
            if not os.isatty(fd):
                continue
            arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8)
            height, width = array.array(r'h', arri)[:2]
            if width > 0 and height > 0:
                return width, height
        except ValueError:
            pass
        except IOError as e:
            if e[0] == errno.EINVAL:
                pass
            else:
                raise
    return 80, 24