annotate docs/evolve-faq.rst @ 227:abe52cf492ee

doc: several update and review.

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Evolve How To
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Add a changeset: ``commit``
------------------------------------------------------------

Just use commit as usual. New changesets will be in the `draft` phase.

Rewrite a changeset: ``amend``
------------------------------------------------------------

A dedicated command ``hg amend`` is added by the extension. It writes a new
changeset combining working-directory parent changes and parent. It will work on
any `draft` or `secret` changeset. It will not work on `public` changesets.

To understand what the result of amend will be I use the two following
aliases  [#]_::

    # diff what amend will look likes
    pdiff=diff --rev .^

    # status what amend will look likes
    pstatus=status --rev .^

It takes various options to pick an author, a date and the branch of the
result... (see ``hg help amend`` for details).

This command can even be invoked on changesets with children (provided
none is public) !

.. note:: The amend command is very similar to mq's ``qrefresh``, a ``refresh``
          alias for amend is also available. But note that contrary to
          ``qrefresh``, ``amend`` does not exclude changes on file not specified
          on the command line.

          XXX add idank example

.. warning:: The `hg commit --amend` switch does **not** lay obsolete marker
             down yet. You should always prefer the dedicated command.

.. [#] (added by enable.sh)



Move a changeset: ``graft``
------------------------------------------------------------

The graft command introduced in 2.0 allows to "copy changes from other
branches onto the current branch".

The graft command has been altered to allow the creation of an
obsolete marker between both the result cset and its source
(actually recording changeset movements).

This is achieved using a new flag `-O` (or `old-obsolete`) [#]_.


XXX Need a few examples here.

.. warning:: when using graft --continue after conflict resolution you **MUST**
             pass `-O` or `-o` flag again because they are not saved for now


.. [#] add this `-O` to graft instead of a dedicated command is probably
       abusive. But this was very convenient for experimental purposes.
       This will likely change in non experimental release.


Delete a changeset: ``kill``
------------------------------------------------------------

A new ``kill``[#]_ command allows removing a changeset.

Just use ``hg kill <some-rev>``.

.. [#] `kill` is a terrible name. **NEVER** forget to add `hg` in front of it
        until we find a better name.

Moving within the history: ``up`` ``gdown`` and ``gup``
------------------------------------------------------------

While working on mutable part of the history you often need to move between
mutable commit.

You just need to use standard update to work with evolve. For convenience, you
can use ``hg gup`` to move to children commit or ``hg gdown`` to move to working
directory parent commit.

.. note:: those command only exist for the convenience of getting qpush and qpop
          feeling back.

Collapse changesets: ``amend``
------------------------------------------------------------

You can use amend -c to collapse multiple changeset in a single one.


.. note:: This is a terrible UI. `hg collapse` should be ported to obsolete
          marker for this purpose.

Split a changeset
-----------------------

There is no official command to split a changeset [#]_ . However is it easily achieved
by manual operation::

  ### you want to split changeset A: 42
  # update to A parent
  $ hg up 42^
  # restore content from A
  $ hg revert -r 42 --all
  # partially commit the first part
  $ hg record
  # commit the second part
  $ hg commit
  # informs mercurial of what appened
  # current changeset (.) and previous one (.^) replace A (42)
  $ hg kill --new . --new .^ 42

.. [#] Yet


Update my current work in progess after a pull
----------------------------------------------

Whenever you are working on some changesets, it is more likely that a pull 
will, eventually, import new changesets in your tree.

And it is likely that you will want your work in progress changesets to be 
rebased on the top of this newly imported subtree.

Doing so is only a matter of rebasing. Rebase have been wrapped to lay obsolete
marker down.


XXX Add an example here.



Move multiple changesets: ``rebase``
------------------------------------------------------------

You can still use rebase to move a whole segment of the changeset graph together.

.. warning:: Beware that rebasing changesets already obsolete by others will result in
             conflicting versions of the changesets.

Stabilize history: ``stabilize``
------------------------------------------------------------

When you rewrite (amend) a changeset with children without rewriting
those children you create *unstable* changesets and *suspended
obsolete* changesets.

When you are finished amending a given changeset, you will want to
declare it stable, in other words rebase its former descendants on its
newest version. This is not done automatically to avoid the
proliferation of useless hidden changesets.

.. warning::

    * ``hg stabilize`` have no --continue to use after conflict
             resolution

    *  stabilization does not handle deletion yet.

    * stabilization does not handle rewriting conflict yet.

    *  obsolete currently relies on changesets in secret phase
       to avoid exchanging extinct() changesets.


Fix my history afterward: ``kill -n``
------------------------------------------------------------

Sometimes you need to create an obsolete marker by hand. This may happen when
upstream has applied some of your patches for example.

You can use ``hg kill --new <new-changeset> <old-changeset>`` to add obsolete
marker.

Export to mq: ``qsync``
------------------------------------------------------------

Another extension allows to export mutable changeset to mq. See the
`enable-qsync.sh` to enable it and read module documentation for details.

If you do not work at Logilab. You probably do not need it.


View diff from the last amend
------------------------------------------------------------

An ``odiff`` alias have been added by ``enable.sh``

:: 
    [alias]
    odiff = diff --rev 'limit(obsparents(.),1)' --rev .

The qt viewer `hgview` displays obsolete data and allows to see diff again
obsolete parent.

View obsolete markers
------------------------------------------------------------

hgview is the only viewer that support this feature. You need an experimental
version available here:

    $ hg clone http://hg-dev.octopoid.net/hgwebdir.cgi/hgview/