annotate mercurial/txnutil.py @ 43506:9f70512ae2cf

cleanup: remove pointless r-prefixes on single-quoted strings

This is the promised second step on single-quoted strings. These had
existed because our source transformer didn't turn r'' into b'', so we
had tagged some strings as r-strings to get "native" strings on both
Pythons. Now that the transformer is gone, we can dispense with this
nonsense.

Methodology:

I ran

    hg locate 'set:added() or modified() or clean()' | egrep '.*\.py$'  | xargs egrep --color=never -n  -- \[\^b\]\[\^a-z\]r\'\[\^\'\\\\\]\*\'\[\^\'\

in an emacs grep-mode buffer, and then used a keyboard macro to
iterate over the results and remove the r prefix as needed.

# skip-blame removing unneeded r prefixes left over from Python 3 migration.

Differential Revision: https://phab.mercurial-scm.org/D7306

# 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(b'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(b'%s.pending' % filename, **kwargs), True)
        except IOError as inst:
            if inst.errno != errno.ENOENT:
                raise
    return (vfs(filename, **kwargs), False)