view mercurial/txnutil.py @ 31827:220d4bffd23e

run-tests: prevent a (glob) declaration from reordering (?) lines

Previously, if a series of optional output lines marked with '(?)' had a (glob)
in one of the first lines, the output would be reordered such that it came last
if none of the lines were output.  The (re) declaration wasn't affected, which
was helpful in figuring this out.  There were no tests for '(re) (?)' so add
that to make sure everything plays nice.

# 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)