annotate mercurial/txnutil.py @ 51292:9c5bd485fbb6

pytype: ignore some signature mismatch in configitems

pytype is grumpy about the dict.update having a more complex signature than the
one we use here.

pytype error:

  itemregister: Overriding method signature mismatch [signature-mismatch]
    Base signature: 'def builtins.dict.update(self) -> None'.
    Subclass signature: 'def itemregister.update(self, other) -> Any'.
    Parameter 'other' must have a default value.

# 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 . 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 FileNotFoundError:
            pass
    return (vfs(filename, **kwargs), False)