# Evolve How To

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

## Rewrite a changeset: amend

A new 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 [1]:

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

# status what amend will look like
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 are public.

Note

As 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.

 [1] (defined by the evolve extension for you)

## Move a changeset: graft

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

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

This is achieved using a new flag -O (or old-obsolete) [2].

XXX example

Warning

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

 [2] 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: prune

A new prune command allows removing a changeset.

Just use hg prune <some-rev>.

## Moving within the history: upgdown and gup

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

You just need to use standard update to work with evolve. For convenience, you can use hg gup to move to the child commit or hg gdown to move to the parent commit.

Note

Those commands only exist for the convenience of getting qpush and qpop feeling back.

## Collapse changesets: fold

You can use hg fold to collapse multiple changesets in a single one.

## Getting changes out of a commit

The hg uncommit command lets you rewrite the parent commit without selected changed files. Target files content is not altered and appears again as "modified":

$hg st M babar M celestine$ hg commit babar celestine
$hg st$ hg uncommit celestine
$hg status M celestine  ## Split a changeset To split on file boundaries, just use uncommit command. If you need a fine-grained split, there is no official command for that yet. However, it is easily achieved by manual operation: ### you want to split changeset A: 42 # update to A parent$ 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 prune --new . --new .^ 42


For more complexe scenario we recommend the use of the histedit_ extension.

## Update my current work in progress 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.

## Move multiple changesets: rebase

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

Warning

Beware that rebasing obsolete changesets will result in conflicting versions of the changesets.

## Resolve history troubles: evolve

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.

## Fix my history afterward: prune -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 prune --new <new-changeset> <old-changeset> to add obsolete marker.

## Export to mq: synchronize

Another extension allows to export your changes to mq.

## View diff from the last amend

An odiff alias have been added by enable.sh

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

## View obsolete markers

hgview is the only viewer that currently supports this feature. You need version 1.6.2

You can also use a debug command

\$ hg debugobsolete
5eb72dbe0cb4 e8db4aa611f6 c4cbebac3751 4f1c269eab68

## View change to your file

Extinct changesets are hidden using the hidden feature of mercurial.

Only hg log, hg glog and hgview support it, other graphical viewer do not.