view mercurial/txnutil.py @ 31132:bbdd712e9adb

minirst: support passing admonitions into findadmonitions() and parse()

This will allow consumers to declare a custom list of admonitions
to parse. Without this patch, custom admonitions would get removed
when prunecomments() is run. We could add an argument controlling
whether prunecomments() is run. However, it is better to convert
the "paragraph" block to an "admonition" block so consumers don't
have to parse for custom admonitions.

# txnutil.py - transaction related utilities
#
#  Copyright FUJIWARA Katsunori <[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

from . import (
    encoding,
)

def mayhavepending(root):
    '''return whether 'root' may have pending changes, which are
    visible to this process.
    '''
    return root == encoding.environ.get('HG_PENDING')

def trypending(root, vfs, filename, **kwargs):
    '''Open  file to be read according to HG_PENDING environment variable

    This opens '.pending' of specified 'filename' only when HG_PENDING
    is equal to 'root'.

    This returns '(fp, is_pending_opened)' tuple.
    '''
    if mayhavepending(root):
        try:
            return (vfs('%s.pending' % filename, **kwargs), True)
        except IOError as inst:
            if inst.errno != errno.ENOENT:
                raise
    return (vfs(filename, **kwargs), False)