/brz/remove-bazaar

====================

Bazaar Release Notes

====================

.. contents::

IN DEVELOPMENT

==============

  CHANGES:

   * The default branch and repository format has changed to 

     ``dirstate-tags``, so tag commands are active by default.

     This format is compatible with Bazaar 0.15 and later.

     (Martin Pool)

  FEATURES:

    * New option ``--author`` in ``bzr commit`` to specify the author of the

      change, if it's different from the committer.  (Lukáš Lalinský)

  BUG FIXES:

    * Suppress warning "integer argument expected, got float" from Paramiko,

      which sometimes caused false test failures.  (Martin Pool)

    * Fix bug in bundle 4 that could cause attempts to write data to wrong

      versionedfile.  (Aaron Bentley)

    * Diffs generated using "diff -p" no longer break the patch parser.

      (Aaron Bentley)

    * get_transport treats an empty possible_transports list the same as a non-

      empty one.  (Aaron Bentley)

    * patch verification for merge directives is reactivated, and works with

      CRLF and CR files.  (Aaron Bentley)

    * Accept ..\ as a path in revision specifiers. This fixes for example

      "-r branch:..\other-branch" on Windows.  (Lukáš Lalinský) 

    * ``BZR_PLUGIN_PATH`` may now contain trailing slashes.

      (Blake Winton, #129299)

  IMPROVEMENTS:

    * ``pull`` and ``merge`` are much faster at installing bundle format 4.

      (Aaron Bentley)

    * ``pull -v`` no longer includes deltas, making it much faster.

      (Aaron Bentley)

    * ``send`` now sends the directive as an attachment by default.

      (Aaron Bentley, Lukáš Lalinský, Alexander Belchenko)

    * Documentation updates (Martin Albisetti)

    * Help on debug flags is now included in ``help global-options``.

      (Daniel Watkins, #124853)

  API BREAKS:

   * ``Branch.append_revision`` is removed altogether; please use 

     ``Branch.set_last_revision_info`` instead.  (Martin Pool)

   * ``Transport.should_cache`` has been removed.  It was not called in the

     previous release.  (Martin Pool)

   * NULL_REVISION is returned to indicate the null revision, not None.

     (Aaron Bentley)

  INTERNALS:

   * New trace function ``mutter_callsite`` will print out a subset of the

     stack to the log, which can be useful for gathering debug details.

     (Robert Collins)

    * ``bzrlib.pack.ContainerWriter`` now tracks how many records have been

      added via a public attribute records_written. (Robert Collins)

    * New method ``bzrlib.transport.Transport.get_recommended_page_size``.

      This provides a hint to users of transports as to the reasonable

      minimum data to read. In principle this can take latency and

      bandwidth into account on a per-connection basis, but for now it

      just has hard coded values based on the url. (e.g. http:// has a large

      page size, file:// has a small one.) (Robert Collins)

    * New method on ``bzrlib.transport.Transport`` ``open_write_stream`` allows

      incremental addition of data to a file without requiring that all the

      data be buffered in memory. (Robert Collins)

  TESTING:

    * Use UTF-8 encoded StringIO for log tests to avoid failures on

      non-ASCII committer names.  (Lukáš Lalinský)

bzr 0.90 2007-08-??

===================

  IMPROVEMENTS:

    * Documentation is now organized into multiple directories with a level

      added for different languages or locales. Added the Mini Tutorial

      and Quick Start Summary (en) documents from the Wiki, improving the

      content and readability of the former. Formatted NEWS as Release Notes

      complete with a Table of Conents, one heading per release. Moved the

      Developer Guide into the main document catalog and provided a link

      from the developer document catalog back to the main one.

      (Ian Clatworthy, Sabin Iacob, Alexander Belchenko)

  API CHANGES:

    * The static convenience method ``BzrDir.create_repository``

      is deprecated.  Callers should instead create a ``BzrDir`` instance

      and call ``create_repository`` on that.  (Martin Pool)

bzr 0.90rc1 2007-08-14

======================

  BUGFIXES:

    * ``bzr init`` should connect to the remote location one time only.  We

      have been connecting several times because we forget to pass around the

      Transport object. This modifies ``BzrDir.create_branch_convenience``,

      so that we can give it the Transport we already have.

      (John Arbash Meinel, Vincent Ladeuil, #111702)

    * Get rid of sftp connection cache (get rid of the FTP one too).

      (Vincent Ladeuil, #43731)

    * bzr branch {local|remote} remote don't try to create a working tree

      anymore.

      (Vincent Ladeuil, #112173)

    * All identified multiple connections for a single bzr command have been

      fixed. See bzrlib/tests/commands directory.

      (Vincent Ladeuil)

    * ``bzr rm`` now does not insist on ``--force`` to delete files that

      have been renamed but not otherwise modified.  (Marius Kruger,

      #111664)

    * ``bzr selftest --bench`` no longer emits deprecation warnings

      (Lukáš Lalinský)

    * ``bzr status`` now honours FILE parameters for conflict lists

      (Aaron Bentley, #127606)

    * ``bzr checkout`` now honours -r when reconstituting a working tree.

      It also honours -r 0.  (Aaron Bentley, #127708)

    * ``bzr add *`` no more fails on Windows if working tree contains

      non-ascii file names. (Kuno Meyer, #127361)

    * allow ``easy_install bzr`` runs without fatal errors. 

      (Alexander Belchenko, #125521)

    * Graph._filter_candidate_lca does not raise KeyError if a candidate

      is eliminated just before it would normally be examined.  (Aaron Bentley)

    * SMTP connection failures produce a nice message, not a traceback.

      (Aaron Bentley)

  IMPROVEMENTS:

    * Don't show "dots" progress indicators when run non-interactively, such

      as from cron.  (Martin Pool)

    * ``info`` now formats locations more nicely and lists "submit" and

      "public" branches (Aaron Bentley)

    * New ``pack`` command that will trigger database compression within

      the repository (Robert Collins)

    * Implement ``_KnitIndex._load_data`` in a pyrex extension. The pyrex

      version is approximately 2-3x faster at parsing a ``.kndx`` file.

      Which yields a measurable improvement for commands which have to

      read from the repository, such as a 1s => 0.75s improvement in

      ``bzr diff`` when there are changes to be shown.  (John Arbash Meinel)

    * Merge is now faster.  Depending on the scenario, it can be more than 2x

      faster. (Aaron Bentley)

    * Give a clearer warning, and allow ``python setup.py install`` to

      succeed even if pyrex is not available.

      (John Arbash Meinel)

    * ``DirState._read_dirblocks`` now has an optional Pyrex

      implementation. This improves the speed of any command that has to

      read the entire DirState. (``diff``, ``status``, etc, improve by

      about 10%).

      ``bisect_dirblocks`` has also been improved, which helps all

      ``_get_entry`` type calls (whenever we are searching for a

      particular entry in the in-memory DirState).

      (John Arbash Meinel)

    * ``bzr pull`` and ``bzr push`` no longer do a complete walk of the 

      branch revision history for ui display unless -v is supplied.

      (Robert Collins)

    * ``bzr log -rA..B`` output shifted to the left margin if the log only 

      contains merge revisions. (Kent Gibson) 

    * The ``plugins`` command is now public with improved help.

      (Ian Clatworthy)

    * New bundle and merge directive formats are faster to generate, and

    * Annotate merge now works when there are local changes. (Aaron Bentley)

    * Commit now only shows the progress in terms of directories instead of

      entries. (Ian Clatworthy)

    * Fix ``KnitRepository.get_revision_graph`` to not request the graph 2

      times. This makes ``get_revision_graph`` 2x faster. (John Arbash

      Meinel)

    * Fix ``VersionedFile.get_graph()`` to avoid using

      ``set.difference_update(other)``, which has bad scaling when

      ``other`` is large. This improves ``VF.get_graph([version_id])`` for

      a 12.5k graph from 2.9s down to 200ms. (John Arbash Meinel)

    * The ``--lsprof-file`` option now generates output for KCacheGrind if

      the file starts with ``callgrind.out``. This matches the default file

      filtering done by KCacheGrind's Open Dialog. (Ian Clatworthy)

    * Fix ``bzr update`` to avoid an unnecessary

      ``branch.get_master_branch`` call, which avoids 1 extra connection

      to the remote server. (Partial fix for #128076, John Arbash Meinel)

    * Log errors from the smart server in the trace file, to make debugging 

      test failures (and live failures!) easier.  (Andrew Bennetts)

    * The HTML version of the man page has been superceded by a more

      comprehensive manual called the Bazaar User Reference. This manual

      is completed generated from the online help topics. As part of this

      change, limited reStructuredText is now explicitly supported in help

      topics and command help with 'unnatural' markup being removed prior

      to display by the online help or inclusion in the man page.

      (Ian Clatworthy)

    * HTML documentation now use files extension ``*.html``

      (Alexander Belchenko)

    * The cache of ignore definitions is now cleared in WorkingTree.unlock()

      so that changes to .bzrignore aren't missed. (#129694, Daniel Watkins)

    * ``bzr selftest --strict`` fails if there are any missing features or

      expected test failures. (Daniel Watkins, #111914)

    * Link to registration survey added to README. (Ian Clatworthy)

    * Windows standalone installer show link to registration survey

      when installation finished. (Alexander Belchenko)

  LIBRARY API BREAKS:

    * Deprecated dictionary ``bzrlib.option.SHORT_OPTIONS`` removed.

      Options are now required to provide a help string and it must

      comply with the style guide by being one or more sentences with an

      initial capital and final period. (Martin Pool)

    * KnitIndex.get_parents now returns tuples. (Robert Collins)

    * Ancient unused ``Repository.text_store`` attribute has been removed.

      (Robert Collins)

    * The ``bzrlib.pack`` interface has changed to use tuples of bytestrings

      rather than just bytestrings, making it easier to represent multiple

      element names. As this interface was not used by any internal facilities

      since it was introduced in 0.18 no API compatibility is being preserved.

      The serialised form of these packs is identical with 0.18 when a single

      element tuple is in use. (Robert Collins)

  INTERNALS:

    * merge now uses ``iter_changes`` to calculate changes, which makes room for

      future performance increases.  It is also more consistent with other

      operations that perform comparisons, and reduces reliance on

      Tree.inventory.  (Aaron Bentley)

    * Refactoring of transport classes connected to a remote server.

      ConnectedTransport is a new class that serves as a basis for all

      transports needing to connect to a remote server.  transport.split_url

      have been deprecated, use the static method on the object instead. URL

      tests have been refactored too.

      (Vincent Ladeuil)

    * Better connection sharing for ConnectedTransport objects.

      transport.get_transport() now accepts a 'possible_transports' parameter.

      If a newly requested transport can share a connection with one of the

      list, it will.

      (Vincent Ladeuil)

    * Most functions now accept ``bzrlib.revision.NULL_REVISION`` to indicate

      the null revision, and consider using ``None`` for this purpose

      deprecated.  (Aaron Bentley)

    * New ``index`` module with abstract index functionality. This will be

      used during the planned changes in the repository layer. Currently the

      index layer provides a graph aware immutable index, a builder for the

      same index type to allow creating them, and finally a composer for

      such indices to allow the use of many indices in a single query. The

      index performance is not optimised, however the API is stable to allow

      development on top of the index. (Robert Collins)

    * ``bzrlib.dirstate.cmp_by_dirs`` can be used to compare two paths by

      their directory sections. This is equivalent to comparing

      ``path.split('/')``, only without having to split the paths.

      This has a Pyrex implementation available.

      (John Arbash Meinel)

    * New transport decorator 'unlistable+' which disables the list_dir

      functionality for testing.

    * Deprecated ``change_entry`` in transform.py. (Ian Clatworthy)

    * RevisionTree.get_weave is now deprecated.  Tree.plan_merge is now used

      for performing annotate-merge.  (Aaron Bentley)

    * New EmailMessage class to create email messages. (Adeodato Simó)

    * Unused functions on the private interface KnitIndex have been removed.

      (Robert Collins)

    * New ``knit.KnitGraphIndex`` which provides a ``KnitIndex`` layered on top

      of a ``index.GraphIndex``. (Robert Collins)

    * New ``knit.KnitVersionedFile.iter_parents`` method that allows querying

      the parents of many knit nodes at once, reducing round trips to the 

      underlying index. (Robert Collins)

    * Graph now has an is_ancestor method, various bits use it.

      (Aaron Bentley)

    * The ``-Dhpss`` flag now includes timing information. As well as

      logging when a new connection is opened. (John Arbash Meinel)

    * ``bzrlib.pack.ContainerWriter`` now returns an offset, length tuple to

      callers when inserting data, allowing generation of readv style access

      during pack creation, without needing a separate pass across the output

      pack to gather such details. (Robert Collins)

    * ``bzrlib.pack.make_readv_reader`` allows readv based access to pack

      files that are stored on a transport. (Robert Collins)

    * New ``Repository.has_same_location`` method that reports if two

      repository objects refer to the same repository (although with some risk

      of false negatives).  (Andrew Bennetts)

    * InterTree.compare now passes require_versioned on correctly.

      (Marius Kruger)

    * New methods on Repository - ``start_write_group``,

      ``commit_write_group``, ``abort_write_group`` and ``is_in_write_group`` -

      which provide a clean hook point for transactional Repositories - ones

      where all the data for a fetch or commit needs to be made atomically

      available in one step. This allows the write lock to remain while making

      a series of data insertions.  (e.g. data conversion). (Robert Collins)

    * In ``bzrlib.knit`` the internal interface has been altered to use

      3-tuples (index, pos, length) rather than two-tuples (pos, length) to

      describe where data in a knit is, allowing knits to be split into 

      many files. (Robert Collins)

    * ``bzrlib.knit._KnitData`` split into cache management and physical access

      with two access classes - ``_PackAccess`` and ``_KnitAccess`` defined.

      The former provides access into a .pack file, and the latter provides the

      current production repository form of .knit files. (Robert Collins)

  TESTING:

    * Remove selftest ``--clean-output``, ``--numbered-dirs`` and

      ``--keep-output`` options, which are obsolete now that tests

      are done within directories in $TMPDIR.  (Martin Pool)

    * The SSH_AUTH_SOCK environment variable is now reset to avoid 

      interaction with any running ssh agents.  (Jelmer Vernooij, #125955)

    * run_bzr_subprocess handles parameters the same way as run_bzr:

      either a string or a list of strings should be passed as the first

      parameter.  Varargs-style parameters are deprecated. (Aaron Bentley)

bzr 0.18  2007-07-17

====================

  BUGFIXES:

    * Fix 'bzr add' crash under Win32 (Kuno Meyer)

bzr 0.18rc1  2007-07-10

=======================

  BUGFIXES:

    * Do not suppress pipe errors, etc. in non-display commands

      (Alexander Belchenko, #87178)

    * Display a useful error message when the user requests to annotate

      a file that is not present in the specified revision.

      (James Westby, #122656)

    * Commands that use status flags now have a reference to 'help

      status-flags'.  (Daniel Watkins, #113436)

    * Work around python-2.4.1 inhability to correctly parse the

      authentication header.

      (Vincent Ladeuil, #121889)

    * Use exact encoding for merge directives. (Adeodato Simó, #120591)

    * Fix tempfile permissions error in smart server tar bundling under

      Windows. (Martin _, #119330)

    * Fix detection of directory entries in the inventory. (James Westby)

    * Fix handling of http code 400: Bad Request When issuing too many ranges.

      (Vincent Ladeuil, #115209)

    * Issue a CONNECT request when connecting to an https server

      via a proxy to enable SSL tunneling.

      (Vincent Ladeuil, #120678)

    * Fix ``bzr log -r`` to support selecting merge revisions, both 

      individually and as part of revision ranges.

      (Kent Gibson, #4663)

    * Don't leave cruft behind when failing to acquire a lockdir.

      (Martin Pool, #109169)

    * Don't use the '-f' strace option during tests.

      (Vincent Ladeuil, #102019).

    * Warn when setting ``push_location`` to a value that will be masked by

      locations.conf.  (Aaron Bentley, #122286)

    * Fix commit ordering in corner case (Aaron Bentley, #94975)

    *  Make annotate behave in a non-ASCII world (Adeodato Simó).

  IMPROVEMENTS:

    * The --lsprof-file option now dumps a text rendering of the profiling

      information if the filename ends in ".txt". It will also convert the

      profiling information to a format suitable for KCacheGrind if the

      output filename ends in ".callgrind". Fixes to the lsprofcalltree

      conversion process by Jean Paul Calderone and Itamar were also merged.

      See http://ddaa.net/blog/python/lsprof-calltree. (Ian Clatworthy)

    * ``info`` now defaults to non-verbose mode, displaying only paths and

      abbreviated format info.  ``info -v`` displays all the information

      formerly displayed by ``info``.  (Aaron Bentley, Adeodato Simó)

    * ``bzr missing`` now has better option names ``--this`` and ``--other``.

      (Elliot Murphy)

    * The internal ``weave-list`` command has become ``versionedfile-list``,

      and now lists knits as well as weaves.  (Aaron Bentley)

    * Automatic merge base selection uses a faster algorithm that chooses

      better bases in criss-cross merge situations (Aaron Bentley)

    * Progress reporting in ``commit`` has been improved. The various logical

      stages are now reported on as follows, namely:

      * Collecting changes [Entry x/y] - Stage n/m

      * Saving data locally - Stage n/m

      * Uploading data to master branch - Stage n/m

      * Updating the working tree - Stage n/m

      * Running post commit hooks - Stage n/m

      If there is no master branch, the 3rd stage is omitted and the total

      number of stages is adjusted accordingly.

      Each hook that is run after commit is listed with a name (as hooks

      can be slow it is useful feedback).

      (Ian Clatworthy, Robert Collins)

    * Various operations that are now faster due to avoiding unnecessary

      topological sorts. (Aaron Bentley)

    * Make merge directives robust against broken bundles. (Aaron Bentley)

    * The lsprof filename note is emitted via trace.note(), not standard

      output.  (Aaron Bentley)

    * ``bzrlib`` now exports explicit API compatibility information to assist

      library users and plugins. See the ``bzrlib.api`` module for details.

      (Robert Collins)

    * Remove unnecessary lock probes when acquiring a lockdir.

      (Martin Pool)

    * ``bzr --version`` now shows the location of the bzr log file, which

      is especially useful on Windows.  (Martin Pool)

    * -D now supports hooks to get debug tracing of hooks (though its currently

      minimal in nature). (Robert Collins)

    * Long log format reports deltas on merge revisions. 

      (John Arbash Meinel, Kent Gibson)

    * Make initial push over ftp more resilient. (John Arbash Meinel)

    * Print a summary of changes for update just like pull does.

      (Daniel Watkins, #113990)

    * Add a -Dhpss option to trace smart protocol requests and responses.

      (Andrew Bennetts)

  LIBRARY API BREAKS:

    * Testing cleanups - 

      ``bzrlib.repository.RepositoryTestProviderAdapter`` has been moved

      to ``bzrlib.tests.repository_implementations``;

      ``bzrlib.repository.InterRepositoryTestProviderAdapter`` has been moved

      to ``bzrlib.tests.interrepository_implementations``;

      ``bzrlib.transport.TransportTestProviderAdapter`` has moved to 

      ``bzrlib.tests.test_transport_implementations``.

      ``bzrlib.branch.BranchTestProviderAdapter`` has moved to

      ``bzrlib.tests.branch_implementations``.

      ``bzrlib.bzrdir.BzrDirTestProviderAdapter`` has moved to 

      ``bzrlib.tests.bzrdir_implementations``.

      ``bzrlib.versionedfile.InterVersionedFileTestProviderAdapter`` has moved

      to ``bzrlib.tests.interversionedfile_implementations``.

      ``bzrlib.store.revision.RevisionStoreTestProviderAdapter`` has moved to

      ``bzrlib.tests.revisionstore_implementations``.

      ``bzrlib.workingtree.WorkingTreeTestProviderAdapter`` has moved to

      ``bzrlib.tests.workingtree_implementations``.

      These changes are an API break in the testing infrastructure only.

      (Robert Collins)

    * Relocate TestCaseWithRepository to be more central. (Robert Collins)

    * ``bzrlib.add.smart_add_tree`` will no longer perform glob expansion on

      win32. Callers of the function should do this and use the new

      ``MutableTree.smart_add`` method instead. (Robert Collins)

    * ``bzrlib.add.glob_expand_for_win32`` is now

      ``bzrlib.win32utils.glob_expand``.  (Robert Collins)

    * ``bzrlib.add.FastPath`` is now private and moved to 

      ``bzrlib.mutabletree._FastPath``. (Robert Collins, Martin Pool)

    * ``LockDir.wait`` removed.  (Martin Pool)

    * The ``SmartServer`` hooks API has changed for the ``server_started`` and

      ``server_stopped`` hooks. The first parameter is now an iterable of

      backing URLs rather than a single URL. This is to reflect that many

      URLs may map to the external URL of the server. E.g. the server interally

      may have a chrooted URL but also the local file:// URL will be at the 

      same location. (Robert Collins)

  INTERNALS:

    * New SMTPConnection class to unify email handling.  (Adeodato Simó)

    * Fix documentation of BzrError. (Adeodato Simó)

    * Make BzrBadParameter an internal error. (Adeodato Simó)

    * Remove use of 'assert False' to raise an exception unconditionally.

      (Martin Pool)

    * Give a cleaner error when failing to decode knit index entry.

      (Martin Pool)

    * TreeConfig would mistakenly search the top level when asked for options

      from a section. It now respects the section argument and only

      searches the specified section. (James Westby)

    * Improve ``make api-docs`` output. (John Arbash Meinel)

    * Use os.lstat rather than os.stat for osutils.make_readonly and

      osutils.make_writeable. This makes the difftools plugin more

      robust when dangling symlinks are found. (Elliot Murphy)

    * New ``-Dlock`` option to log (to ~/.bzr.log) information on when 

      lockdirs are taken or released.  (Martin Pool)

    * ``bzrlib`` Hooks are now nameable using ``Hooks.name_hook``. This 

      allows a nicer UI when hooks are running as the current hook can

      be displayed. (Robert Collins)

    * ``Transport.get`` has had its interface made more clear for ease of use.

      Retrieval of a directory must now fail with either 'PathError' at open

      time, or raise 'ReadError' on a read. (Robert Collins)

    * New method ``_maybe_expand_globs`` on the ``Command`` class for 

      dealing with unexpanded glob lists - e.g. on the win32 platform. This

      was moved from ``bzrlib.add._prepare_file_list``. (Robert Collins)

    * ``bzrlib.add.smart_add`` and ``bzrlib.add.smart_add_tree`` are now

      deprecated in favour of ``MutableTree.smart_add``. (Robert Collins,

      Martin Pool)

    * New method ``external_url`` on Transport for obtaining the url to

      hand to external processes. (Robert Collins)

    * Teach windows installers to build pyrex/C extensions.

      (Alexander Belchenko)

  TESTING:

    * Removed the ``--keep-output`` option from selftest and clean up test

      directories as they're used.  This reduces the IO load from 

      running the test suite and cuts the time by about half.

      (Andrew Bennetts, Martin Pool)

    * Add scenarios as a public attribute on the TestAdapter classes to allow

      modification of the generated scenarios before adaption and easier

      testing. (Robert Collins)

    * New testing support class ``TestScenarioApplier`` which multiplies

      out a single teste by a list of supplied scenarios. (RobertCollins)

    * Setting ``repository_to_test_repository`` on a repository_implementations

      test will cause it to be called during repository creation, allowing the

      testing of repository classes which are not based around the Format

      concept. For example a repository adapter can be tested in this manner,

      by altering the repository scenarios to include a scenario that sets this

      attribute during the test parameterisation in

      ``bzrlib.tests.repository.repository_implementations``. (Robert Collins)

    * Clean up many of the APIs for blackbox testing of Bazaar.  The standard 

      interface is now self.run_bzr.  The command to run can be passed as

      either a list of parameters, a string containing the command line, or

      (deprecated) varargs parameters.  (Martin Pool)

    * The base TestCase now isolates tests from -D parameters by clearing

      ``debug.debug_flags`` and restores it afterwards. (Robert Collins)

    * Add a relpath parameter to get_transport methods in test framework to

      avoid useless cloning.

      (Vincent Ladeuil, #110448)

bzr 0.17  2007-06-18

====================

  BUGFIXES:

    * Fix crash of commit due to wrong lookup of filesystem encoding.

      (Colin Watson, #120647)

    * Revert logging just to stderr in commit as broke unicode filenames.

      (Aaron Bentley, Ian Clatworthy, #120930)

bzr 0.17rc1  2007-06-12

=======================

  NOTES WHEN UPGRADING:

    * The kind() and is_executable() APIs on the WorkingTree interface no

      longer implicitly (read) locks and unlocks the tree. This *might*

      impact some plug-ins and tools using this part of the API. If you find

      an issue that may be caused by this change, please let us know,

      particularly the plug-in/tool maintainer. If encountered, the API

      fix is to surround kind() and is_executable() calls with lock_read()

      and unlock() like so::

        work_tree.lock_read()

        try:

            kind = work_tree.kind(...)

        finally:

            work_tree.unlock()

  INTERNALS:

    * Rework of LogFormatter API to provide beginning/end of log hooks and to

      encapsulate the details of the revision to be logged in a LogRevision

      object.

      In long log formats, merge revision ids are only shown when --show-ids

      is specified, and are labelled "revision-id:", as per mainline

      revisions, instead of "merged:". (Kent Gibson)

    * New ``BranchBuilder`` API which allows the construction of particular

      histories quickly. Useful for testing and potentially other applications

      too. (Robert Collins)

  IMPROVEMENTS:

    * There are two new help topics, working-trees and repositories that

      attempt to explain these concepts. (James Westby, John Arbash Meinel,

      Aaron Bentley)

    * Added ``bzr log --limit`` to report a limited number of revisions.

      (Kent Gibson, #3659)

    * Revert does not try to preserve file contents that were originally

      produced by reverting to a historical revision.  (Aaron Bentley)