hgext/win32text.py

clone: fix race with same target directory (issue716)

Whichever side creates .hg first wins the race, and the other aborts
politely without deleting the tree.

from mercurial import util, ui
from mercurial.i18n import gettext as _
import re

# regexp for single LF without CR preceding.
re_single_lf = re.compile('(^|[^\r])\n', re.MULTILINE)

def dumbdecode(s, cmd):
    # warn if already has CRLF in repository.
    # it might cause unexpected eol conversion.
    # see issue 302:
    #   http://www.selenic.com/mercurial/bts/issue302
    if '\r\n' in s:
        u = ui.ui()
        u.warn(_('WARNING: file in repository already has CRLF line ending \n'
                 ' which does not need eol conversion by win32text plugin.\n'
                 ' Please reconsider encode/decode setting in'
                 ' mercurial.ini or .hg/hgrc\n'
                 ' before next commit.\n'))
    # replace single LF to CRLF
    return re_single_lf.sub('\\1\r\n', s)

def dumbencode(s, cmd):
    return s.replace('\r\n', '\n')

def clevertest(s, cmd):
    if '\0' in s: return False
    return True

def cleverdecode(s, cmd):
    if clevertest(s, cmd):
        return dumbdecode(s, cmd)
    return s

def cleverencode(s, cmd):
    if clevertest(s, cmd):
        return dumbencode(s, cmd)
    return s

util.filtertable.update({
    'dumbdecode:': dumbdecode,
    'dumbencode:': dumbencode,
    'cleverdecode:': cleverdecode,
    'cleverencode:': cleverencode,
    })