~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 by Canonical Ltd
# -*- coding: utf-8 -*-

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


"""Black-box tests for bzr.

These check that it behaves properly when it's invoked through the regular
command-line interface. This doesn't actually run a new interpreter but 
rather starts again from the run_bzr function.
"""


from cStringIO import StringIO
import os
import shutil
import sys
import os

from bzrlib.branch import Branch
from bzrlib.errors import BzrCommandError
from bzrlib.osutils import has_symlinks
from bzrlib.selftest import TestCaseInTempDir, BzrTestBase
from bzrlib.selftest.HTTPTestUtil import TestCaseWithWebserver


class ExternalBase(TestCaseInTempDir):

    def runbzr(self, args, retcode=0, backtick=False):
        if isinstance(args, basestring):
            args = args.split()

        if backtick:
            return self.run_bzr_captured(args, retcode=retcode)[0]
        else:
            return self.run_bzr_captured(args, retcode=retcode)


class TestCommands(ExternalBase):

    def test_help_commands(self):
        self.runbzr('--help')
        self.runbzr('help')
        self.runbzr('help commands')
        self.runbzr('help help')
        self.runbzr('commit -h')

    def test_init_branch(self):
        self.runbzr(['init'])

    def test_whoami(self):
        # this should always identify something, if only "john@localhost"
        self.runbzr("whoami")
        self.runbzr("whoami --email")

        self.assertEquals(self.runbzr("whoami --email",
                                      backtick=True).count('@'), 1)
        
    def test_whoami_branch(self):
        """branch specific user identity works."""
        self.runbzr('init')
        f = file('.bzr/email', 'wt')
        f.write('Branch Identity <branch@identi.ty>')
        f.close()
        bzr_email = os.environ.get('BZREMAIL')
        if bzr_email is not None:
            del os.environ['BZREMAIL']
        whoami = self.runbzr("whoami",backtick=True)
        whoami_email = self.runbzr("whoami --email",backtick=True)
        self.assertTrue(whoami.startswith('Branch Identity <branch@identi.ty>'))
        self.assertTrue(whoami_email.startswith('branch@identi.ty'))
        # Verify that the environment variable overrides the value 
        # in the file
        os.environ['BZREMAIL'] = 'Different ID <other@environ.ment>'
        whoami = self.runbzr("whoami",backtick=True)
        whoami_email = self.runbzr("whoami --email",backtick=True)
        self.assertTrue(whoami.startswith('Different ID <other@environ.ment>'))
        self.assertTrue(whoami_email.startswith('other@environ.ment'))
        if bzr_email is not None:
            os.environ['BZREMAIL'] = bzr_email

    def test_invalid_commands(self):
        self.runbzr("pants", retcode=1)
        self.runbzr("--pants off", retcode=1)
        self.runbzr("diff --message foo", retcode=1)

    def test_empty_commit(self):
        self.runbzr("init")
        self.build_tree(['hello.txt'])
        self.runbzr("commit -m empty", retcode=1)
        self.runbzr("add hello.txt")
        self.runbzr("commit -m added")

    def test_empty_commit_message(self):
        self.runbzr("init")
        file('foo.c', 'wt').write('int main() {}')
        self.runbzr(['add', 'foo.c'])
        self.runbzr(["commit", "-m", ""] , retcode=1) 

    def test_ignore_patterns(self):
        from bzrlib.branch import Branch
        
        b = Branch.initialize('.')
        self.assertEquals(list(b.unknowns()), [])

        file('foo.tmp', 'wt').write('tmp files are ignored')
        self.assertEquals(list(b.unknowns()), [])
        assert self.capture('unknowns') == ''

        file('foo.c', 'wt').write('int main() {}')
        self.assertEquals(list(b.unknowns()), ['foo.c'])
        assert self.capture('unknowns') == 'foo.c\n'

        self.runbzr(['add', 'foo.c'])
        assert self.capture('unknowns') == ''

        # 'ignore' works when creating the .bzignore file
        file('foo.blah', 'wt').write('blah')
        self.assertEquals(list(b.unknowns()), ['foo.blah'])
        self.runbzr('ignore *.blah')
        self.assertEquals(list(b.unknowns()), [])
        assert file('.bzrignore', 'rU').read() == '*.blah\n'

        # 'ignore' works when then .bzrignore file already exists
        file('garh', 'wt').write('garh')
        self.assertEquals(list(b.unknowns()), ['garh'])
        assert self.capture('unknowns') == 'garh\n'
        self.runbzr('ignore garh')
        self.assertEquals(list(b.unknowns()), [])
        assert file('.bzrignore', 'rU').read() == '*.blah\ngarh\n'

    def test_revert(self):
        self.runbzr('init')

        file('hello', 'wt').write('foo')
        self.runbzr('add hello')
        self.runbzr('commit -m setup hello')

        file('goodbye', 'wt').write('baz')
        self.runbzr('add goodbye')
        self.runbzr('commit -m setup goodbye')

        file('hello', 'wt').write('bar')
        file('goodbye', 'wt').write('qux')
        self.runbzr('revert hello')
        self.check_file_contents('hello', 'foo')
        self.check_file_contents('goodbye', 'qux')
        self.runbzr('revert')
        self.check_file_contents('goodbye', 'baz')

        os.mkdir('revertdir')
        self.runbzr('add revertdir')
        self.runbzr('commit -m f')
        os.rmdir('revertdir')
        self.runbzr('revert')

        os.symlink('/unlikely/to/exist', 'symlink')
        self.runbzr('add symlink')
        self.runbzr('commit -m f')
        os.unlink('symlink')
        self.runbzr('revert')
        
        file('hello', 'wt').write('xyz')
        self.runbzr('commit -m xyz hello')
        self.runbzr('revert -r 1 hello')
        self.check_file_contents('hello', 'foo')
        self.runbzr('revert hello')
        self.check_file_contents('hello', 'xyz')
        os.chdir('revertdir')
        self.runbzr('revert')
        os.chdir('..')


    def test_mv_modes(self):
        """Test two modes of operation for mv"""
        from bzrlib.branch import Branch
        b = Branch.initialize('.')
        self.build_tree(['a', 'c', 'subdir/'])
        self.run_bzr_captured(['add', self.test_dir])
        self.run_bzr_captured(['mv', 'a', 'b'])
        self.run_bzr_captured(['mv', 'b', 'subdir'])
        self.run_bzr_captured(['mv', 'subdir/b', 'a'])
        self.run_bzr_captured(['mv', 'a', 'c', 'subdir'])
        self.run_bzr_captured(['mv', 'subdir/a', 'subdir/newa'])

    def test_main_version(self):
        """Check output from version command and master option is reasonable"""
        # output is intentionally passed through to stdout so that we
        # can see the version being tested
        output = self.runbzr('version', backtick=1)
        self.log('bzr version output:')
        self.log(output)
        self.assert_(output.startswith('bzr (bazaar-ng) '))
        self.assertNotEqual(output.index('Canonical'), -1)
        # make sure --version is consistent
        tmp_output = self.runbzr('--version', backtick=1)
        self.log('bzr --version output:')
        self.log(tmp_output)
        self.assertEquals(output, tmp_output)

    def example_branch(test):
        test.runbzr('init')
        file('hello', 'wt').write('foo')
        test.runbzr('add hello')
        test.runbzr('commit -m setup hello')
        file('goodbye', 'wt').write('baz')
        test.runbzr('add goodbye')
        test.runbzr('commit -m setup goodbye')

    def test_export(self):
        os.mkdir('branch')
        os.chdir('branch')
        self.example_branch()
        self.runbzr('export ../latest')
        self.assertEqual(file('../latest/goodbye', 'rt').read(), 'baz')
        self.runbzr('export ../first -r 1')
        assert not os.path.exists('../first/goodbye')
        self.assertEqual(file('../first/hello', 'rt').read(), 'foo')
        self.runbzr('export ../first.gz -r 1')
        self.assertEqual(file('../first.gz/hello', 'rt').read(), 'foo')
        self.runbzr('export ../first.bz2 -r 1')
        self.assertEqual(file('../first.bz2/hello', 'rt').read(), 'foo')
        self.runbzr('export ../first.tar -r 1')
        assert os.path.isfile('../first.tar')
        from tarfile import TarFile
        tf = TarFile('../first.tar')
        assert 'first/hello' in tf.getnames(), tf.getnames()
        self.assertEqual(tf.extractfile('first/hello').read(), 'foo')
        self.runbzr('export ../first.tar.gz -r 1')
        assert os.path.isfile('../first.tar.gz')
        self.runbzr('export ../first.tbz2 -r 1')
        assert os.path.isfile('../first.tbz2')
        self.runbzr('export ../first.tar.bz2 -r 1')
        assert os.path.isfile('../first.tar.bz2')
        self.runbzr('export ../first.tar.tbz2 -r 1')
        assert os.path.isfile('../first.tar.tbz2')
        from bz2 import BZ2File
        tf = TarFile('../first.tar.tbz2', 
                     fileobj=BZ2File('../first.tar.tbz2', 'r'))
        assert 'first.tar/hello' in tf.getnames(), tf.getnames()
        self.assertEqual(tf.extractfile('first.tar/hello').read(), 'foo')
        self.runbzr('export ../first2.tar -r 1 --root pizza')
        tf = TarFile('../first2.tar')
        assert 'pizza/hello' in tf.getnames(), tf.getnames()

    def test_diff(self):
        self.example_branch()
        file('hello', 'wt').write('hello world!')
        self.runbzr('commit -m fixing hello')
        output = self.runbzr('diff -r 2..3', backtick=1)
        self.assert_('\n+hello world!' in output)
        output = self.runbzr('diff -r last:3..last:1', backtick=1)
        self.assert_('\n+baz' in output)

    def test_branch(self):
        """Branch from one branch to another."""
        os.mkdir('a')
        os.chdir('a')
        self.example_branch()
        os.chdir('..')
        self.runbzr('branch a b')
        self.runbzr('branch a c -r 1')
        os.chdir('b')
        self.runbzr('commit -m foo --unchanged')
        os.chdir('..')
        # naughty - abstraction violations RBC 20050928  
        print "test_branch used to delete the stores, how is this meant to work ?"
        #shutil.rmtree('a/.bzr/revision-store')
        #shutil.rmtree('a/.bzr/inventory-store', ignore_errors=True)
        #shutil.rmtree('a/.bzr/text-store', ignore_errors=True)
        self.runbzr('branch a d --basis b')

    def test_merge(self):
        from bzrlib.branch import Branch
        
        os.mkdir('a')
        os.chdir('a')
        self.example_branch()
        os.chdir('..')
        self.runbzr('branch a b')
        os.chdir('b')
        file('goodbye', 'wt').write('quux')
        self.runbzr(['commit',  '-m',  "more u's are always good"])

        os.chdir('../a')
        file('hello', 'wt').write('quuux')
        # We can't merge when there are in-tree changes
        self.runbzr('merge ../b', retcode=1)
        self.runbzr(['commit', '-m', "Like an epidemic of u's"])
        self.runbzr('merge ../b')
        self.check_file_contents('goodbye', 'quux')
        # Merging a branch pulls its revision into the tree
        a = Branch.open('.')
        b = Branch.open('../b')
        a.get_revision_xml(b.last_revision())
        self.log('pending merges: %s', a.pending_merges())
        #        assert a.pending_merges() == [b.last_revision()], "Assertion %s %s" \
        #        % (a.pending_merges(), b.last_revision())

    def test_merge_with_missing_file(self):
        """Merge handles missing file conflicts"""
        os.mkdir('a')
        os.chdir('a')
        os.mkdir('sub')
        print >> file('sub/a.txt', 'wb'), "hello"
        print >> file('b.txt', 'wb'), "hello"
        print >> file('sub/c.txt', 'wb'), "hello"
        self.runbzr('init')
        self.runbzr('add')
        self.runbzr(('commit', '-m', 'added a'))
        self.runbzr('branch . ../b')
        print >> file('sub/a.txt', 'ab'), "there"
        print >> file('b.txt', 'ab'), "there"
        print >> file('sub/c.txt', 'ab'), "there"
        self.runbzr(('commit', '-m', 'Added there'))
        os.unlink('sub/a.txt')
        os.unlink('sub/c.txt')
        os.rmdir('sub')
        os.unlink('b.txt')
        self.runbzr(('commit', '-m', 'Removed a.txt'))
        os.chdir('../b')
        print >> file('sub/a.txt', 'ab'), "something"
        print >> file('b.txt', 'ab'), "something"
        print >> file('sub/c.txt', 'ab'), "something"
        self.runbzr(('commit', '-m', 'Modified a.txt'))
        self.runbzr('merge ../a/')
        assert os.path.exists('sub/a.txt.THIS')
        assert os.path.exists('sub/a.txt.BASE')
        os.chdir('../a')
        self.runbzr('merge ../b/')
        assert os.path.exists('sub/a.txt.OTHER')
        assert os.path.exists('sub/a.txt.BASE')

    def test_pull(self):
        """Pull changes from one branch to another."""
        os.mkdir('a')
        os.chdir('a')

        self.example_branch()
        self.runbzr('pull', retcode=1)
        self.runbzr('missing', retcode=1)
        self.runbzr('missing .')
        self.runbzr('missing')
        self.runbzr('pull')
        self.runbzr('pull /', retcode=1)
        self.runbzr('pull')

        os.chdir('..')
        self.runbzr('branch a b')
        os.chdir('b')
        self.runbzr('pull')
        os.mkdir('subdir')
        self.runbzr('add subdir')
        self.runbzr('commit -m blah --unchanged')
        os.chdir('../a')
        a = Branch.open('.')
        b = Branch.open('../b')
        assert a.revision_history() == b.revision_history()[:-1]
        self.runbzr('pull ../b')
        assert a.revision_history() == b.revision_history()
        self.runbzr('commit -m blah2 --unchanged')
        os.chdir('../b')
        self.runbzr('commit -m blah3 --unchanged')
        self.runbzr('pull ../a', retcode=1)
        print "DECIDE IF PULL CAN CONVERGE, blackbox.py"
        return
        os.chdir('../a')
        self.runbzr('merge ../b')
        self.runbzr('commit -m blah4 --unchanged')
        os.chdir('../b/subdir')
        self.runbzr('pull ../../a')
        assert a.revision_history()[-1] == b.revision_history()[-1]
        self.runbzr('commit -m blah5 --unchanged')
        self.runbzr('commit -m blah6 --unchanged')
        os.chdir('..')
        self.runbzr('pull ../a')
        os.chdir('../a')
        self.runbzr('commit -m blah7 --unchanged')
        self.runbzr('merge ../b')
        self.runbzr('commit -m blah8 --unchanged')
        self.runbzr('pull ../b')
        self.runbzr('pull ../b')
        
    def test_add_reports(self):
        """add command prints the names of added files."""
        b = Branch.initialize('.')
        self.build_tree(['top.txt', 'dir/', 'dir/sub.txt'])
        out = self.run_bzr_captured(['add'], retcode = 0)[0]
        # the ordering is not defined at the moment
        results = sorted(out.rstrip('\n').split('\n'))
        self.assertEquals(['added dir',
                           'added dir'+os.sep+'sub.txt',
                           'added top.txt',],
                          results)

    def test_unknown_command(self):
        """Handling of unknown command."""
        out, err = self.run_bzr_captured(['fluffy-badger'],
                                         retcode=1)
        self.assertEquals(out, '')
        err.index('unknown command')


def listdir_sorted(dir):
    L = os.listdir(dir)
    L.sort()
    return L


class OldTests(ExternalBase):
    """old tests moved from ./testbzr."""

    def test_bzr(self):
        from os import chdir, mkdir
        from os.path import exists

        runbzr = self.runbzr
        capture = self.capture
        progress = self.log

        progress("basic branch creation")
        mkdir('branch1')
        chdir('branch1')
        runbzr('init')

        self.assertEquals(capture('root').rstrip(),
                          os.path.join(self.test_dir, 'branch1'))

        progress("status of new file")

        f = file('test.txt', 'wt')
        f.write('hello world!\n')
        f.close()

        self.assertEquals(capture('unknowns'), 'test.txt\n')

        out = capture("status")
        assert out == 'unknown:\n  test.txt\n'

        out = capture("status --all")
        assert out == "unknown:\n  test.txt\n"

        out = capture("status test.txt --all")
        assert out == "unknown:\n  test.txt\n"

        f = file('test2.txt', 'wt')
        f.write('goodbye cruel world...\n')
        f.close()

        out = capture("status test.txt")
        assert out == "unknown:\n  test.txt\n"

        out = capture("status")
        assert out == ("unknown:\n"
                       "  test.txt\n"
                       "  test2.txt\n")

        os.unlink('test2.txt')

        progress("command aliases")
        out = capture("st --all")
        assert out == ("unknown:\n"
                       "  test.txt\n")

        out = capture("stat")
        assert out == ("unknown:\n"
                       "  test.txt\n")

        progress("command help")
        runbzr("help st")
        runbzr("help")
        runbzr("help commands")
        runbzr("help slartibartfast", 1)

        out = capture("help ci")
        out.index('aliases: ')

        progress("can't rename unversioned file")
        runbzr("rename test.txt new-test.txt", 1)

        progress("adding a file")

        runbzr("add test.txt")
        assert capture("unknowns") == ''
        assert capture("status --all") == ("added:\n"
                                                "  test.txt\n")

        progress("rename newly-added file")
        runbzr("rename test.txt hello.txt")
        assert os.path.exists("hello.txt")
        assert not os.path.exists("test.txt")

        assert capture("revno") == '0\n'

        progress("add first revision")
        runbzr(['commit', '-m', 'add first revision'])

        progress("more complex renames")
        os.mkdir("sub1")
        runbzr("rename hello.txt sub1", 1)
        runbzr("rename hello.txt sub1/hello.txt", 1)
        runbzr("move hello.txt sub1", 1)

        runbzr("add sub1")
        runbzr("rename sub1 sub2")
        runbzr("move hello.txt sub2")
        assert capture("relpath sub2/hello.txt") == os.path.join("sub2", "hello.txt\n")

        assert exists("sub2")
        assert exists("sub2/hello.txt")
        assert not exists("sub1")
        assert not exists("hello.txt")

        runbzr(['commit', '-m', 'commit with some things moved to subdirs'])

        mkdir("sub1")
        runbzr('add sub1')
        runbzr('move sub2/hello.txt sub1')
        assert not exists('sub2/hello.txt')
        assert exists('sub1/hello.txt')
        runbzr('move sub2 sub1')
        assert not exists('sub2')
        assert exists('sub1/sub2')

        runbzr(['commit', '-m', 'rename nested subdirectories'])

        chdir('sub1/sub2')
        self.assertEquals(capture('root')[:-1],
                          os.path.join(self.test_dir, 'branch1'))
        runbzr('move ../hello.txt .')
        assert exists('./hello.txt')
        self.assertEquals(capture('relpath hello.txt'),
                          os.path.join('sub1', 'sub2', 'hello.txt') + '\n')
        assert capture('relpath ../../sub1/sub2/hello.txt') == os.path.join('sub1', 'sub2', 'hello.txt\n')
        runbzr(['commit', '-m', 'move to parent directory'])
        chdir('..')
        assert capture('relpath sub2/hello.txt') == os.path.join('sub1', 'sub2', 'hello.txt\n')

        runbzr('move sub2/hello.txt .')
        assert exists('hello.txt')

        f = file('hello.txt', 'wt')
        f.write('some nice new content\n')
        f.close()

        f = file('msg.tmp', 'wt')
        f.write('this is my new commit\n')
        f.close()

        runbzr('commit -F msg.tmp')

        assert capture('revno') == '5\n'
        runbzr('export -r 5 export-5.tmp')
        runbzr('export export.tmp')

        runbzr('log')
        runbzr('log -v')
        runbzr('log -v --forward')
        runbzr('log -m', retcode=1)
        log_out = capture('log -m commit')
        assert "this is my new commit" in log_out
        assert "rename nested" not in log_out
        assert 'revision-id' not in log_out
        assert 'revision-id' in capture('log --show-ids -m commit')


        progress("file with spaces in name")
        mkdir('sub directory')
        file('sub directory/file with spaces ', 'wt').write('see how this works\n')
        runbzr('add .')
        runbzr('diff')
        runbzr('commit -m add-spaces')
        runbzr('check')

        runbzr('log')
        runbzr('log --forward')

        runbzr('info')

        if has_symlinks():
            progress("symlinks")
            mkdir('symlinks')
            chdir('symlinks')
            runbzr('init')
            os.symlink("NOWHERE1", "link1")
            runbzr('add link1')
            assert self.capture('unknowns') == ''
            runbzr(['commit', '-m', '1: added symlink link1'])
    
            mkdir('d1')
            runbzr('add d1')
            assert self.capture('unknowns') == ''
            os.symlink("NOWHERE2", "d1/link2")
            assert self.capture('unknowns') == 'd1/link2\n'
            # is d1/link2 found when adding d1
            runbzr('add d1')
            assert self.capture('unknowns') == ''
            os.symlink("NOWHERE3", "d1/link3")
            assert self.capture('unknowns') == 'd1/link3\n'
            runbzr(['commit', '-m', '2: added dir, symlink'])
    
            runbzr('rename d1 d2')
            runbzr('move d2/link2 .')
            runbzr('move link1 d2')
            assert os.readlink("./link2") == "NOWHERE2"
            assert os.readlink("d2/link1") == "NOWHERE1"
            runbzr('add d2/link3')
            runbzr('diff')
            runbzr(['commit', '-m', '3: rename of dir, move symlinks, add link3'])
    
            os.unlink("link2")
            os.symlink("TARGET 2", "link2")
            os.unlink("d2/link1")
            os.symlink("TARGET 1", "d2/link1")
            runbzr('diff')
            assert self.capture("relpath d2/link1") == "d2/link1\n"
            runbzr(['commit', '-m', '4: retarget of two links'])
    
            runbzr('remove d2/link1')
            assert self.capture('unknowns') == 'd2/link1\n'
            runbzr(['commit', '-m', '5: remove d2/link1'])
    
            os.mkdir("d1")
            runbzr('add d1')
            runbzr('rename d2/link3 d1/link3new')
            assert self.capture('unknowns') == 'd2/link1\n'
            runbzr(['commit', '-m', '6: remove d2/link1, move/rename link3'])
            
            runbzr(['check'])
            
            runbzr(['export', '-r', '1', 'exp1.tmp'])
            chdir("exp1.tmp")
            assert listdir_sorted(".") == [ "link1" ]
            assert os.readlink("link1") == "NOWHERE1"
            chdir("..")
            
            runbzr(['export', '-r', '2', 'exp2.tmp'])
            chdir("exp2.tmp")
            assert listdir_sorted(".") == [ "d1", "link1" ]
            chdir("..")
            
            runbzr(['export', '-r', '3', 'exp3.tmp'])
            chdir("exp3.tmp")
            assert listdir_sorted(".") == [ "d2", "link2" ]
            assert listdir_sorted("d2") == [ "link1", "link3" ]
            assert os.readlink("d2/link1") == "NOWHERE1"
            assert os.readlink("link2")    == "NOWHERE2"
            chdir("..")
            
            runbzr(['export', '-r', '4', 'exp4.tmp'])
            chdir("exp4.tmp")
            assert listdir_sorted(".") == [ "d2", "link2" ]
            assert os.readlink("d2/link1") == "TARGET 1"
            assert os.readlink("link2")    == "TARGET 2"
            assert listdir_sorted("d2") == [ "link1", "link3" ]
            chdir("..")
            
            runbzr(['export', '-r', '5', 'exp5.tmp'])
            chdir("exp5.tmp")
            assert listdir_sorted(".") == [ "d2", "link2" ]
            assert os.path.islink("link2")
            assert listdir_sorted("d2")== [ "link3" ]
            chdir("..")
            
            runbzr(['export', '-r', '6', 'exp6.tmp'])
            chdir("exp6.tmp")
            assert listdir_sorted(".") == [ "d1", "d2", "link2" ]
            assert listdir_sorted("d1") == [ "link3new" ]
            assert listdir_sorted("d2") == []
            assert os.readlink("d1/link3new") == "NOWHERE3"
            chdir("..")
        else:
            progress("skipping symlink tests")


class HttpTests(TestCaseWithWebserver):
    """Test bzr ui commands against remote branches."""

    def test_branch(self):
        os.mkdir('from')
        branch = Branch.initialize('from')
        branch.commit('empty commit for nonsense', allow_pointless=True)
        url = self.get_remote_url('from')
        self.run_bzr('branch', url, 'to')
        branch = Branch.open('to')
        self.assertEqual(1, len(branch.revision_history()))