view mercurial/txnutil.py @ 33115:fa9a90d5ad89

tests: save the original PATH and PYTHONPATH variables

When running the tests, define ORIG_PATH and ORIG_PYTHONPATH environment
variables that contain the original contents of PATH and PYTHONPATH, before
they were modified by run-tests.py

This will make it possible for tests to refer to the original contents of these
variables if necessary.  In particular, this is necessary for invoking the
correct version of hg for examining the local repository (the mercurial
repository itself, not the temporary test repositories).  Various tests examine
the local repository to check the file lists and contents of commit messages.

# 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)