hgext/bookflow.py

convert: don't drop commits that are empty in the source when using --filemap

I ran into this when using `hg lfconvert --to-normal` (which uses the filemap
class internally), and saw that commits with nothing but a branch change were
dropped.  We could put in an option that only lfconvert uses internally.  But
silently dropping anything other than a commit where all changes were excluded
seems unintended.  For example, there's a message in mercurial_sink.putcommit()
if it drops an empty commit.  (And the reason that isn't kicking in here is
because lfconvert isn't passing --filemap, so the self.filemapmode conditional
there is always False.)

The naive change of `return not files` broke test-convert-filemap.t, so this is
a little more elaborate than needed for converting from largefiles.

"""implements bookmark-based branching (EXPERIMENTAL)

 - Disables creation of new branches (config: enable_branches=False).
 - Requires an active bookmark on commit (config: require_bookmark=True).
 - Doesn't move the active bookmark on update, only on commit.
 - Requires '--rev' for moving an existing bookmark.
 - Protects special bookmarks (config: protect=@).

 flow related commands

    :hg book NAME: create a new bookmark
    :hg book NAME -r REV: move bookmark to revision (fast-forward)
    :hg up|co NAME: switch to bookmark
    :hg push -B .: push active bookmark
"""
from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    bookmarks,
    commands,
    error,
    extensions,
    registrar,
)

MY_NAME = 'bookflow'

configtable = {}
configitem = registrar.configitem(configtable)

configitem(MY_NAME, 'protect', ['@'])
configitem(MY_NAME, 'require-bookmark', True)
configitem(MY_NAME, 'enable-branches', False)

cmdtable = {}
command = registrar.command(cmdtable)

def commit_hook(ui, repo, **kwargs):
    active = repo._bookmarks.active
    if active:
        if active in ui.configlist(MY_NAME, 'protect'):
            raise error.Abort(
                _('cannot commit, bookmark %s is protected') % active)
        if not cwd_at_bookmark(repo, active):
            raise error.Abort(
       _('cannot commit, working directory out of sync with active bookmark'),
                hint=_("run 'hg up %s'") % active)
    elif ui.configbool(MY_NAME, 'require-bookmark', True):
        raise error.Abort(_('cannot commit without an active bookmark'))
    return 0

def bookmarks_update(orig, repo, parents, node):
    if len(parents) == 2:
        # called during commit
        return orig(repo, parents, node)
    else:
        # called during update
        return False

def bookmarks_addbookmarks(
        orig, repo, tr, names, rev=None, force=False, inactive=False):
    if not rev:
        marks = repo._bookmarks
        for name in names:
            if name in marks:
                raise error.Abort(_(
                    "bookmark %s already exists, to move use the --rev option"
                    ) % name)
    return orig(repo, tr, names, rev, force, inactive)

def commands_commit(orig, ui, repo, *args, **opts):
    commit_hook(ui, repo)
    return orig(ui, repo, *args, **opts)

def commands_pull(orig, ui, repo, *args, **opts):
    rc = orig(ui, repo, *args, **opts)
    active = repo._bookmarks.active
    if active and not cwd_at_bookmark(repo, active):
        ui.warn(_(
            "working directory out of sync with active bookmark, run "
            "'hg up %s'"
        ) % active)
    return rc

def commands_branch(orig, ui, repo, label=None, **opts):
    if label and not opts.get(r'clean') and not opts.get(r'rev'):
        raise error.Abort(
         _("creating named branches is disabled and you should use bookmarks"),
            hint="see 'hg help bookflow'")
    return orig(ui, repo, label, **opts)

def cwd_at_bookmark(repo, mark):
    mark_id = repo._bookmarks[mark]
    cur_id = repo.lookup('.')
    return cur_id == mark_id

def uisetup(ui):
    extensions.wrapfunction(bookmarks, 'update', bookmarks_update)
    extensions.wrapfunction(bookmarks, 'addbookmarks', bookmarks_addbookmarks)
    extensions.wrapcommand(commands.table, 'commit', commands_commit)
    extensions.wrapcommand(commands.table, 'pull', commands_pull)
    if not ui.configbool(MY_NAME, 'enable-branches'):
        extensions.wrapcommand(commands.table, 'branch', commands_branch)