view hgext/fetch.py @ 12998:91cb08a9e7fb

discovery: list new remote heads in prepush() on --debug

With this patch applied, Mercurial will list the hashes of new remote heads
if push --debug aborts because of new remote heads (option -f/--force not set).

Example:

  $ hg push --debug repo1
  using http://example.org/repo1
  http auth: user johndoe, password not set
  sending between command
  pushing to http://example.org/repo1
  sending capabilities command
  capabilities: changegroupsubset stream=1 lookup pushkey unbundle=HG10GZ,HG10BZ,HG10UN branchmap
  sending heads command
  searching for changes
  common changesets up to 609edbc7853f
  sending branchmap command
  new remote heads on branch 'default'        <- new output line
  new remote head 5862c07f53a2                <- new output line
  abort: push creates new remote heads on branch 'default'!
  (did you forget to merge? use push -f to force)

Compare to without --debug (not changed by this patch, including it here
for reference purposes only):

  $ hg push repo1
  pushing to http://example.org/repo1
  searching for changes
  abort: push creates new remote heads on branch 'default'!
  (did you forget to merge? use push -f to force)

Motivation for this change:

'hg outgoing' may list a whole lot of benign changesets plus an odd changeset
that will trigger the "new remote heads" abort. It can be hard to spot that
single unwanted changeset (it may be an old forgotten experiment, lingering
in the local repo).

"hg log -r 'heads(outgoing())'" might be useful, but that also lists a head
that may be benign on push.

Inside prepush(), we already know which heads are causing troubles on 'hg push'.
Why not make that info available (at least on --debug)?

This would also be helpful for doing remote support, as the supporter can ask
the user to paste the output of 'hg push --debug' on error and then ask further
questions about the heads listed.

# fetch.py - pull and merge remote changes
#
# Copyright 2006 Vadim Gelfer <[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.

'''pull, update and merge in one command'''

from mercurial.i18n import _
from mercurial.node import nullid, short
from mercurial import commands, cmdutil, hg, util, url, error
from mercurial.lock import release

def fetch(ui, repo, source='default', **opts):
    '''pull changes from a remote repository, merge new changes if needed.

    This finds all changes from the repository at the specified path
    or URL and adds them to the local repository.

    If the pulled changes add a new branch head, the head is
    automatically merged, and the result of the merge is committed.
    Otherwise, the working directory is updated to include the new
    changes.

    When a merge occurs, the newly pulled changes are assumed to be
    "authoritative". The head of the new changes is used as the first
    parent, with local changes as the second. To switch the merge
    order, use --switch-parent.

    See :hg:`help dates` for a list of formats valid for -d/--date.

    Returns 0 on success.
    '''

    date = opts.get('date')
    if date:
        opts['date'] = util.parsedate(date)

    parent, p2 = repo.dirstate.parents()
    branch = repo.dirstate.branch()
    branchnode = repo.branchtags().get(branch)
    if parent != branchnode:
        raise util.Abort(_('working dir not at branch tip '
                           '(use "hg update" to check out branch tip)'))

    if p2 != nullid:
        raise util.Abort(_('outstanding uncommitted merge'))

    wlock = lock = None
    try:
        wlock = repo.wlock()
        lock = repo.lock()
        mod, add, rem, del_ = repo.status()[:4]

        if mod or add or rem:
            raise util.Abort(_('outstanding uncommitted changes'))
        if del_:
            raise util.Abort(_('working directory is missing some files'))
        bheads = repo.branchheads(branch)
        bheads = [head for head in bheads if len(repo[head].children()) == 0]
        if len(bheads) > 1:
            raise util.Abort(_('multiple heads in this branch '
                               '(use "hg heads ." and "hg merge" to merge)'))

        other = hg.repository(hg.remoteui(repo, opts),
                              ui.expandpath(source))
        ui.status(_('pulling from %s\n') %
                  url.hidepassword(ui.expandpath(source)))
        revs = None
        if opts['rev']:
            try:
                revs = [other.lookup(rev) for rev in opts['rev']]
            except error.CapabilityError:
                err = _("Other repository doesn't support revision lookup, "
                        "so a rev cannot be specified.")
                raise util.Abort(err)

        # Are there any changes at all?
        modheads = repo.pull(other, heads=revs)
        if modheads == 0:
            return 0

        # Is this a simple fast-forward along the current branch?
        newheads = repo.branchheads(branch)
        newchildren = repo.changelog.nodesbetween([parent], newheads)[2]
        if len(newheads) == 1:
            if newchildren[0] != parent:
                return hg.clean(repo, newchildren[0])
            else:
                return 0

        # Are there more than one additional branch heads?
        newchildren = [n for n in newchildren if n != parent]
        newparent = parent
        if newchildren:
            newparent = newchildren[0]
            hg.clean(repo, newparent)
        newheads = [n for n in newheads if n != newparent]
        if len(newheads) > 1:
            ui.status(_('not merging with %d other new branch heads '
                        '(use "hg heads ." and "hg merge" to merge them)\n') %
                      (len(newheads) - 1))
            return 1

        # Otherwise, let's merge.
        err = False
        if newheads:
            # By default, we consider the repository we're pulling
            # *from* as authoritative, so we merge our changes into
            # theirs.
            if opts['switch_parent']:
                firstparent, secondparent = newparent, newheads[0]
            else:
                firstparent, secondparent = newheads[0], newparent
                ui.status(_('updating to %d:%s\n') %
                          (repo.changelog.rev(firstparent),
                           short(firstparent)))
            hg.clean(repo, firstparent)
            ui.status(_('merging with %d:%s\n') %
                      (repo.changelog.rev(secondparent), short(secondparent)))
            err = hg.merge(repo, secondparent, remind=False)

        if not err:
            # we don't translate commit messages
            message = (cmdutil.logmessage(opts) or
                       ('Automated merge with %s' %
                        url.removeauth(other.url())))
            editor = cmdutil.commiteditor
            if opts.get('force_editor') or opts.get('edit'):
                editor = cmdutil.commitforceeditor
            n = repo.commit(message, opts['user'], opts['date'], editor=editor)
            ui.status(_('new changeset %d:%s merges remote changes '
                        'with local\n') % (repo.changelog.rev(n),
                                           short(n)))

        return err

    finally:
        release(lock, wlock)

cmdtable = {
    'fetch':
        (fetch,
        [('r', 'rev', [],
          _('a specific revision you would like to pull'), _('REV')),
         ('e', 'edit', None, _('edit commit message')),
         ('', 'force-editor', None, _('edit commit message (DEPRECATED)')),
         ('', 'switch-parent', None, _('switch parents when merging')),
        ] + commands.commitopts + commands.commitopts2 + commands.remoteopts,
        _('hg fetch [SOURCE]')),
}