view hgext/closehead.py @ 42456:87a34c767384

merge: fix race that could cause wrong size in dirstate

The problem is that hg merge/update/etc work the following way:
1. figure out what files to update
2. apply the update to disk
3. apply the update to in-memory dirstate
4. write dirstate

where step3 looks at the filesystem and assumes it sees the result of
step2. If a file is changed between step2 and step3, step3 will record
incorrect information in the dirstate.

I avoid this by passing the size step3 needs directly from step2, for
the common path (not implemented for change/delete conflicts for
instance).

I didn't fix the same race for the exec bit for now, because it's less
likely to be problematic and I had trouble due to the fact that the
dirstate stores the permissions differently from the manifest (st_mode
vs '' 'l' 'x'), in combination with tests that pretend that symlinks
are not supported.

However, I moved the lstat from step3 to step2, which should tighten
the race window markedly, both for the exec bit and for the mtime.

Differential Revision: https://phab.mercurial-scm.org/D6475

# closehead.py - Close arbitrary heads without checking them out first
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''close arbitrary heads without checking them out first'''

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    bookmarks,
    cmdutil,
    context,
    error,
    pycompat,
    registrar,
    scmutil,
)

cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

commitopts = cmdutil.commitopts
commitopts2 = cmdutil.commitopts2
commitopts3 = [('r', 'rev', [],
               _('revision to check'), _('REV'))]

@command('close-head|close-heads', commitopts + commitopts2 + commitopts3,
    _('[OPTION]... [REV]...'),
    helpcategory=command.CATEGORY_CHANGE_MANAGEMENT,
    inferrepo=True)
def close_branch(ui, repo, *revs, **opts):
    """close the given head revisions

    This is equivalent to checking out each revision in a clean tree and running
    ``hg commit --close-branch``, except that it doesn't change the working
    directory.

    The commit message must be specified with -l or -m.
    """
    def docommit(rev):
        cctx = context.memctx(repo, parents=[rev, None], text=message,
                              files=[], filectxfn=None, user=opts.get('user'),
                              date=opts.get('date'), extra=extra)
        tr = repo.transaction('commit')
        ret = repo.commitctx(cctx, True)
        bookmarks.update(repo, [rev, None], ret)
        cctx.markcommitted(ret)
        tr.close()

    opts = pycompat.byteskwargs(opts)

    revs += tuple(opts.get('rev', []))
    revs = scmutil.revrange(repo, revs)

    if not revs:
        raise error.Abort(_('no revisions specified'))

    heads = []
    for branch in repo.branchmap():
        heads.extend(repo.branchheads(branch))
    heads = set(repo[h].rev() for h in heads)
    for rev in revs:
        if rev not in heads:
            raise error.Abort(_('revision is not an open head: %d') % rev)

    message = cmdutil.logmessage(ui, opts)
    if not message:
        raise error.Abort(_("no commit message specified with -l or -m"))
    extra = { 'close': '1' }

    with repo.wlock(), repo.lock():
        for rev in revs:
            r = repo[rev]
            branch = r.branch()
            extra['branch'] = branch
            docommit(r)
    return 0