mercurial/bookmarks.py

bookmarks: restrict moving a bookmark to its descendants (issue1502)

A bookmark can only move to a descendant on commit, pull or
unbundle. Bookmarks cannot jump between heads anymore. This fixese
issue 1502.

We explicitly use new.node(), to emphasise that we are updating the
current bookmark to the new node.

# Mercurial bookmark support code
#
# Copyright 2008 David Soria Parra <[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 mercurial.i18n import _
from mercurial.node import nullid, nullrev, bin, hex, short
from mercurial import encoding, util
import os

def valid(mark):
    for c in (':', '\0', '\n', '\r'):
        if c in mark:
            return False
    return True

def read(repo):
    '''Parse .hg/bookmarks file and return a dictionary

    Bookmarks are stored as {HASH}\\s{NAME}\\n (localtags format) values
    in the .hg/bookmarks file.
    Read the file and return a (name=>nodeid) dictionary
    '''
    try:
        bookmarks = {}
        for line in repo.opener('bookmarks'):
            sha, refspec = line.strip().split(' ', 1)
            refspec = encoding.tolocal(refspec)
            bookmarks[refspec] = repo.changelog.lookup(sha)
    except:
        pass
    return bookmarks

def readcurrent(repo):
    '''Get the current bookmark

    If we use gittishsh branches we have a current bookmark that
    we are on. This function returns the name of the bookmark. It
    is stored in .hg/bookmarks.current
    '''
    mark = None
    if os.path.exists(repo.join('bookmarks.current')):
        file = repo.opener('bookmarks.current')
        # No readline() in posixfile_nt, reading everything is cheap
        mark = encoding.tolocal((file.readlines() or [''])[0])
        if mark == '':
            mark = None
        file.close()
    return mark

def write(repo):
    '''Write bookmarks

    Write the given bookmark => hash dictionary to the .hg/bookmarks file
    in a format equal to those of localtags.

    We also store a backup of the previous state in undo.bookmarks that
    can be copied back on rollback.
    '''
    refs = repo._bookmarks

    try:
        bms = repo.opener('bookmarks').read()
    except IOError:
        bms = ''
    repo.opener('undo.bookmarks', 'w').write(bms)

    if repo._bookmarkcurrent not in refs:
        setcurrent(repo, None)
    for mark in refs.keys():
        if not valid(mark):
            raise util.Abort(_("bookmark '%s' contains illegal "
                "character" % mark))

    wlock = repo.wlock()
    try:

        file = repo.opener('bookmarks', 'w', atomictemp=True)
        for refspec, node in refs.iteritems():
            file.write("%s %s\n" % (hex(node), encoding.fromlocal(refspec)))
        file.rename()

        # touch 00changelog.i so hgweb reloads bookmarks (no lock needed)
        try:
            os.utime(repo.sjoin('00changelog.i'), None)
        except OSError:
            pass

    finally:
        wlock.release()

def setcurrent(repo, mark):
    '''Set the name of the bookmark that we are currently on

    Set the name of the bookmark that we are on (hg update <bookmark>).
    The name is recorded in .hg/bookmarks.current
    '''
    current = repo._bookmarkcurrent
    if current == mark:
        return

    refs = repo._bookmarks

    # do not update if we do update to a rev equal to the current bookmark
    if (mark and mark not in refs and
        current and refs[current] == repo.changectx('.').node()):
        return
    if mark not in refs:
        mark = ''
    if not valid(mark):
        raise util.Abort(_("bookmark '%s' contains illegal "
            "character" % mark))

    wlock = repo.wlock()
    try:
        file = repo.opener('bookmarks.current', 'w', atomictemp=True)
        file.write(mark)
        file.rename()
    finally:
        wlock.release()
    repo._bookmarkcurrent = mark

def update(repo, parents, node):
    marks = repo._bookmarks
    update = False
    mark = repo._bookmarkcurrent
    if mark and marks[mark] in parents:
        old = repo[marks[mark]]
        new = repo[node]
        if new in old.descendants():
            marks[mark] = new.node()
            update = True
    if update:
        write(repo)

def listbookmarks(repo):
    # We may try to list bookmarks on a repo type that does not
    # support it (e.g., statichttprepository).
    if not hasattr(repo, '_bookmarks'):
        return {}

    d = {}
    for k, v in repo._bookmarks.iteritems():
        d[k] = hex(v)
    return d

def pushbookmark(repo, key, old, new):
    w = repo.wlock()
    try:
        marks = repo._bookmarks
        if hex(marks.get(key, '')) != old:
            return False
        if new == '':
            del marks[key]
        else:
            if new not in repo:
                return False
            marks[key] = repo[new].node()
        write(repo)
        return True
    finally:
        w.release()

def diff(ui, repo, remote):
    ui.status(_("searching for changed bookmarks\n"))

    lmarks = repo.listkeys('bookmarks')
    rmarks = remote.listkeys('bookmarks')

    diff = sorted(set(rmarks) - set(lmarks))
    for k in diff:
        ui.write("   %-25s %s\n" % (k, rmarks[k][:12]))

    if len(diff) <= 0:
        ui.status(_("no changed bookmarks found\n"))
        return 1
    return 0