view mercurial/rewriteutil.py @ 39662:50f46b771921

py3: partially fix pager spawning on Windows

Previously, spinning up the pager crashed because the command and environment
was in bytes.  (See also 543a788eea2d.)  Now it aborts with an invalid handle:

    $ HGMODULEPOLICY=py py -3 ../hg --traceback --config extensions.evolve=!
    Traceback (most recent call last):
    File "c:\Users\Matt\projects\hg\mercurial\ui.py", line 967, in _write
      self.fout.write(''.join(msgs))
    File "c:\Users\Matt\projects\hg\mercurial\windows.py", line 173, in write
      self.fp.write(s[start:end])
    OSError: [WinError 6] The handle is invalid

    During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "c:\Users\Matt\projects\hg\mercurial\scmutil.py", line 164, in callcatch
        return func()
      File "c:\Users\Matt\projects\hg\mercurial\dispatch.py", line 350, in _runcatchfunc
        return _dispatch(req)
      File "c:\Users\Matt\projects\hg\mercurial\dispatch.py", line 930, in _dispatch
        return commands.help_(ui, 'shortlist')
      File "c:\Users\Matt\projects\hg\mercurial\commands.py", line 2930, in help_
        ui.write(formatted)
      File "c:\Users\Matt\projects\hg\mercurial\ui.py", line 948, in write
        self._writenobuf(*args, **opts)
      File "c:\Users\Matt\projects\hg\mercurial\ui.py", line 960, in _writenobuf
        self._write(*msgs, **opts)
      File "c:\Users\Matt\projects\hg\mercurial\ui.py", line 969, in _write
        raise error.StdioError(err)
    mercurial.error.StdioError: [Errno 9] The handle is invalid
    abort: The handle is invalid

The interesting bit here is that the abort message is marked with ANSI color,
but the OSError is not.

# rewriteutil.py - utility functions for rewriting changesets
#
# Copyright 2017 Octobus <[e-mail]>
#
# 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

from .i18n import _

from . import (
    error,
    node,
    obsolete,
    revset,
)

def precheck(repo, revs, action='rewrite'):
    """check if revs can be rewritten
    action is used to control the error message.

    Make sure this function is called after taking the lock.
    """
    if node.nullrev in revs:
        msg = _("cannot %s null changeset") % (action)
        hint = _("no changeset checked out")
        raise error.Abort(msg, hint=hint)

    publicrevs = repo.revs('%ld and public()', revs)
    if len(repo[None].parents()) > 1:
        raise error.Abort(_("cannot %s while merging") % action)

    if publicrevs:
        msg = _("cannot %s public changesets") % (action)
        hint = _("see 'hg help phases' for details")
        raise error.Abort(msg, hint=hint)

    newunstable = disallowednewunstable(repo, revs)
    if newunstable:
        raise error.Abort(_("cannot %s changeset with children") % action)

def disallowednewunstable(repo, revs):
    """Checks whether editing the revs will create new unstable changesets and
    are we allowed to create them.

    To allow new unstable changesets, set the config:
        `experimental.evolution.allowunstable=True`
    """
    allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
    if allowunstable:
        return revset.baseset()
    return repo.revs("(%ld::) - %ld", revs, revs)