wireproto: don't expose changegroupsubset capability if not available
We just marked the changegroupsubset command as only available to
version 1 of the wire transports. There is a capability of the same
name of the command that indicates if the command is supported.
This commit teaches the capabilities code to conditionally emit that
capability depending on whether the command is available for the
current transport.
Most test output is reordering of capabilities. But the limited tests
for version 2 of the SSH protocol do show the capability disappearing.
Differential Revision: https://phab.mercurial-scm.org/D2486
# txnutil.py - transaction related utilities
#
# Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> 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)