/brz/remove-bazaar

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

Bazaar Release Notes

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

.. contents::

IN DEVELOPMENT

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

  NOTES WHEN UPGRADING:

   * ``pull``, ``merge`` and ``push`` will no longer silently correct some

     repository index errors that occured as a result of the Weave disk format.

     Instead the ``reconcile`` command needs to be run to correct those

     problems if they exist (and it has been able to fix most such problems

     since bzr 0.8). Some new problems have been identified during this release

     and you should run ``bzr check`` once on every repository to see if you

     need to reconcile. If you cannot ``pull`` or ``merge`` from a remote

     repository due to mismatched parent errors - a symptom of index errors -

     you should simply take a full copy of that remote repository to a clean

     directory outside any local repositories, then run reconcile on it, and

     finally pull from it locally. (And naturally email the repositories owner

     to ask them to upgrade and run reconcile).

     (Robert Collins)

  FEATURES:

   * New ``reconfigure`` command (Aaron Bentley)

  PERFORMANCE:

   * Commit in quiet mode is now slightly faster as the information to

     output is no longer calculated. (Ian Clatworthy)

   * Commit no longer checks for new text keys during insertion when the

     revision id was deterministically unique. (Robert Collins)

   * Committing a change which is not a merge and does not change the number of

     files in the tree is faster by utilising the data about whether files are

     changed to determine if the tree is unchanged rather than recalculating

     it at the end of the commit process. (Robert Collins)

   * Inventory serialisation no longer double-sha's the content.

     (Robert Collins)

   * Partial commits are now approximately 40% faster by walking over the

     unselected current tree more efficiently. (Robert Collins)

   * XML inventory serialisation takes 20% less time while being stricter about

     the contents. (Robert Collins)

  IMPROVEMENTS:

   * Mutt is now a supported mail client; set ``mail_client=mutt`` in your

     bazaar.conf and ``send`` will use mutt. (Keir Mierle)

   * Show encodings, locale and list of plugins in the traceback message.

     (Martin Pool, #63894)

  BUG FIXES:

   * Commands reporting exceptions can now be profiled and still have their

     data correctly dumped to a file. For example, a ``bzr commit`` with

     no changes still reports the operation as pointless but doing so no

     longer throws away the profiling data if this command is run with

     ``--lsprof-file callgrind.out.ci`` say. (Ian Clatworthy)

   * Fallback to ftp when paramiko is not installed and sftp can't be used for

     ``tests/commands`` so that the test suite is still usable without

     paramiko.

     (Vincent Ladeuil, #59150)

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

   * Fix selftest semi-random noise during http related tests.

     (Vincent Ladeuil, #140614)

   * Fix failing test by comparing real paths to cover the case where the TMPDIR

     contains a symbolic link.

     (Vincent Ladeuil, #141382).

   * HttpServer and FtpServer need to be closed properly or a listening socket

     will remain opened.

     (Vincent Ladeuil, #140055)

   * The basename, not the full path, is now used when checking whether

     the profiling dump file begins with ``callgrind.out`` or not. This

     fixes a bug reported by Aaron Bentley on IRC. (Ian Clatworthy)

   * Trivial fix for invoking command ``reconfigure`` without arguments.

     (Rob Weir, #141629)

   * ``WorkingTree.rename_one`` will now raise an error if normalisation of the

     new path causes bzr to be unable to access the file. (Robert Collins)

  API BREAKS:

   * ``KnitVersionedFile.add*`` will no longer cache added records even when

     enable_cache() has been called - the caching feature is now exclusively for

     reading existing data. (Robert Collins)

   * The ``VersionedFile`` interface now allows content checks to be bypassed

     by supplying check_content=False.  This saves nearly 30% of the minimum

     cost to store a version of a file. (Robert Collins)

   * Tree's with bad state such as files with no length or sha will no longer

     be silently accepted by the repository XML serialiser. To serialise

     inventories without such data, pass working=True to write_inventory.

     (Robert Collins)

   * ``VersionedFile.fix_parents`` has been removed as a harmful API.

     ``VersionedFile.join`` will no longer accept different parents on either

     side of a join - it will either ignore them, or error, depending on the

     implementation. See notes when upgrading for more information.

     (Robert Collins)

  INTERNALS:

    * ``bzrlib.transport.Transport.put_file`` now returns the number of bytes

      put by the method call, to allow avoiding stat-after-write or

      housekeeping in callers. (Robert Collins)

   * New method ``bzrlib.osutils.minimum_path_selection`` useful for removing

     duplication from user input, when a user mentions both a path and an item

     contained within that path. (Robert Collins)

   * New method on xml serialisers, write_inventory_to_lines, which matches the

     API used by knits for adding content. (Robert Collins)

   * New helper ``bzrlib.tuned_gzip.bytes_to_gzip`` which takes a byte string

     and returns a gzipped version of the same. This is used to avoid a bunch

     of api friction during adding of knit hunks. (Robert Collins)

   * New parameter yield_parents on ``Inventory.iter_entries_by_dir`` which

     causes the parents of a selected id to be returned recursively, so all the

     paths from the root down to each element of selected_file_ids are

     returned. (Robert Collins)

  TESTING:

bzr 0.91rc2 2007-09-11

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

   * Replaced incorrect tarball for previous release; a debug statement was left 

     in bzrlib/remote.py.

bzr 0.91rc1 2007-09-11

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

  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.

     This incidentally fixes bug #126141.

     (Martin Pool)

   * ``--quiet`` or ``-q`` is no longer a global option. If present, it

     must now appear after the command name. Scripts doing things like

     ``bzr -q missing`` need to be rewritten as ``bzr missing -q``.

     (Ian Clatworthy)

  FEATURES:

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

     change, if it's different from the committer. ``bzr log`` and

     ``bzr annotate`` display the author instead of the committer.

     (Lukáš Lalinský)

   * In addition to global options and command specific options, a set of

     standard options are now supported. Standard options are legal for

     all commands. The initial set of standard options are:

     * ``--help`` or ``-h`` - display help message

     * ``--verbose`` or ``-v`` - display additional information

     * ``--quiet``  or ``-q`` - only output warnings and errors.

     Unlike global options, standard options can be used in aliases and

     may have command-specific help. (Ian Clatworthy)

   * Verbosity level processing has now been unified. If ``--verbose``

     or ``-v`` is specified on the command line multiple times, the

     verbosity level is made positive the first time then increased.

     If ``--quiet`` or ``-q`` is specified on the command line

     multiple times, the verbosity level is made negative the first

     time then decreased. To get the default verbosity level of zero,

     either specify none of the above , ``--no-verbose`` or ``--no-quiet``.

     Note that most commands currently ignore the magnitude of the

     verbosity level but do respect *quiet vs normal vs verbose* when

     generating output. (Ian Clatworthy)

   * ``Branch.hooks`` now supports ``pre_commit`` hook. The hook's signature

     is documented in BranchHooks constructor. (Nam T. Nguyen, #102747)

  BUG FIXES:

   * ``bzr plugins`` now lists the version number for each plugin in square

     brackets after the path. (Robert Collins, #125421)

   * Pushing, pulling and branching branches with subtree references was not

     copying the subtree weave, preventing the file graph from being accessed

     and causing errors in commits in clones. (Robert Collins)

   * 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)

   * man page no longer lists hidden options (#131667, Aaron Bentley)

   * ``uncommit --help`` now explains the -r option adequately.  (Daniel

     Watkins, #106726)

   * Error messages are now better formatted with parameters (such as

     filenames) quoted when necessary. This avoids confusion when directory

     names ending in a '.' at the end of messages were confused with a

     full stop that may or not have been there. (Daniel Watkins, #129791)

   * Fix ``status FILE -r X..Y``. (Lukáš Lalinský)

   * If a particular command is an alias, ``help`` will show the alias

     instead of claiming there is no help for said alias. (Daniel Watkins,

     #133548)

   * TreeTransform-based operations, like pull, merge, revert, and branch,

     now roll back if they encounter an error.  (Aaron Bentley, #67699)

   * ``bzr commit`` now exits cleanly if a character unsupported by the

     current encoding is used in the commit message.  (Daniel Watkins,

     #116143)

   * bzr send uses default values for ranges when only half of an elipsis

     is specified ("-r..5" or "-r5..").  (#61685, Aaron Bentley)

   * Avoid trouble when Windows ssh calls itself 'plink' but no plink

     binary is present.  (Martin Albisetti, #107155)

   * ``bzr remove`` should remove clean subtrees.  Now it will remove (without

     needing ``--force``) subtrees that contain no files with text changes or

     modified files.  With ``--force`` it removes the subtree regardless of

     text changes or unknown files. Directories with renames in or out (but

     not changed otherwise) will now be removed without needing ``--force``.

     Unknown ignored files will be deleted without needing ``--force``.

     (Marius Kruger, #111665)

   * When two plugins conflict, the source of both the losing and now the

     winning definition is shown.  (Konstantin Mikhaylov, #5454)

   * When committing to a branch, the location being committed to is

     displayed.  (Daniel Watkins, #52479)

   * ``bzr --version`` takes care about encoding of stdout, especially

     when output is redirected. (Alexander Belchenko, #131100)

   * Prompt for an ftp password if none is provided.

     (Vincent Ladeuil, #137044)

   * Reuse bound branch associated transport to avoid multiple

     connections.

     (Vincent Ladeuil, #128076, #131396)

   * Overwrite conflicting tags by ``push`` and ``pull`` if the

     ``--overwrite`` option is specified.  (Lukáš Lalinský, #93947)

    * In checkouts, tags are copied into the master branch when created,

      changed or deleted, and are copied into the checkout when it is 

      updated.  (Martin Pool, #93856, #93860)

  IMPROVEMENTS:

   * Add the option "--show-diff" to the commit command in order to display

     the diff during the commit log creation. (Goffredo Baroncelli)

   * ``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)

   * Parameters passed on the command line are checked to ensure they are

     supported by the encoding in use. (Daniel Watkins)

   * The compression used within the bzr repository has changed from zlib

     level 9 to the zlib default level. This improves commit performance with

     only a small increase in space used (and in some cases a reduction in

     space). (Robert Collins)

   * Initial commit no longer SHAs files twice and now reuses the path

     rather than looking it up again, making it faster.

     (Ian Clatworthy)

   * New option ``-c``/``--change`` for ``diff`` and ``status`` to show

     changes in one revision.  (Lukáš Lalinský)

   * If versioned files match a given ignore pattern, a warning is now

     given. (Daniel Watkins, #48623)

   * ``bzr status`` now has -S as a short name for --short and -V as a

     short name for --versioned. These have been added to assist users

     migrating from Subversion: ``bzr status -SV`` is now like

     ``svn status -q``.  (Daniel Watkins, #115990)

   * Added C implementation of  ``PatienceSequenceMatcher``, which is about

     10x faster than the Python version. This speeds up commands that

     need file diffing, such as ``bzr commit`` or ``bzr diff``.

     (Lukáš Lalinský)

   * HACKING has been extended with a large section on core developer tasks.

     (Ian Clatworthy)

   * Add ``branches`` and ``standalone-trees`` as online help topics and

     include them as Concepts within the User Reference.

     (Paul Moore, Ian Clatworthy)

  API BREAKS:

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

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

   * CommitBuilder now advertises itself as requiring the root entry to be

     supplied. This only affects foreign repository implementations which reuse

     CommitBuilder directly and have changed record_entry_contents to require

     that the root not be supplied. This should be precisely zero plugins

     affected. (Robert Collins)

   * The ``add_lines`` methods on ``VersionedFile`` implementations has changed

     its return value to include the sha1 and length of the inserted text. This

     allows the avoidance of double-sha1 calculations during commit.

     (Robert Collins)

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

     previous release.  (Martin Pool)

  TESTING:

   * Tests may now raise TestNotApplicable to indicate they shouldn't be 

     run in a particular scenario.  (Martin Pool)

   * New function multiply_tests_from_modules to give a simpler interface

     to test parameterization.  (Martin Pool, Robert Collins)

   * ``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)

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

     non-ASCII committer names.  (Lukáš Lalinský)

  INTERNALS:

   * ``bzrlib.plugin.all_plugins`` has been deprecated in favour of

     ``bzrlib.plugin.plugins()`` which returns PlugIn objects that provide

     useful functionality for determining the path of a plugin, its tests, and

     its version information. (Robert Collins)

   * Add the option user_encoding to the function 'show_diff_trees()'

     in order to move the user encoding at the UI level. (Goffredo Baroncelli)

   * Add the function make_commit_message_template_encoded() and the function

     edit_commit_message_encoded() which handle encoded strings.

     This is done in order to mix the commit messages (which is a unicode

     string), and the diff which is a raw string. (Goffredo Baroncelli)

   * CommitBuilder now defaults to using add_lines_with_ghosts, reducing

     overhead on non-weave repositories which don't require all parents to be

     present. (Robert Collins)

   * Deprecated method ``find_previous_heads`` on

     ``bzrlib.inventory.InventoryEntry``. This has been superseded by the use

     of ``parent_candidates`` and a separate heads check via the repository

     API. (Robert Collins)

   * 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)

   * New methods on ``bzrlib.knit.KnitVersionedFile``:

     ``get_data_stream(versions)``, ``insert_data_stream(stream)`` and

     ``get_format_signature()``.  These provide some infrastructure for

     efficiently streaming the knit data for a set of versions over the smart

     protocol.

   * Knits with no annotation cache still produce correct annotations.

     (Aaron Bentley)

   * Three new methods have been added to ``bzrlib.trace``:

     ``set_verbosity_level``, ``get_verbosity_level`` and ``is_verbose``.

     ``set_verbosity_level`` expects a numeric value: negative for quiet,

     zero for normal, positive for verbose. The size of the number can be

     used to determine just how quiet or verbose the application should be.

     The existing ``be_quiet`` and ``is_quiet`` routines have been

     integrated into this new scheme. (Ian Clatworthy)

   * Options can now be delcared with a ``custom_callback`` parameter. If

     set, this routine is called after the option is processed. This feature

     is now used by the standard options ``verbose`` and ``quiet`` so that

     setting one implicitly resets the other. (Ian Clatworthy)

   * Rather than declaring a new option from scratch in order to provide

     custom help, a centrally registered option can be decorated using the

     new ``bzrlib.Option.custom_help`` routine. In particular, this routine

     is useful when declaring better help for the ``verbose`` and ``quiet``

     standard options as the base definition of these is now more complex

     than before thanks to their use of a custom callback. (Ian Clatworthy)

    * Tree._iter_changes(specific_file=[]) now iterates through no files,

      instead of iterating through all files.  None is used to iterate through

      all files.  (Aaron Bentley)

    * WorkingTree.revert() now accepts None to revert all files.  The use of

      [] to revert all files is deprecated.  (Aaron Bentley)

bzr 0.90 2007-08-28

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

  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