# evolve extension for Mercurial

## Evolve Tutorial

## Initial setup

This Mercurial configuration example is used for testing.

    $ cat >> $HGRCPATH << EOF
    > [ui]
    > # This is change the default output of log for clear tutorial
    > logtemplate ="{node|short} ({phase}): {desc}\n"
    > [diff]
    > # use "git" diff format, clearer and smarter format
    > git = 1
    > EOF

    $ hg init local
    $ cat >> local/.hg/hgrc << EOF
    > [paths]
    > remote = ../remote
    > other = ../other
    > [ui]
    > user = Babar the King
    > EOF

    $ hg init remote
    $ cat >> remote/.hg/hgrc << EOF
    > [paths]
    > local = ../local
    > [ui]
    > user = Celestine the Queen
    > EOF

    $ hg init other
    $ cat >> other/.hg/hgrc << EOF
    > [ui]
    > user = Princess Flore
    > EOF

This tutorial uses the following configuration for Mercurial:

A compact log template with phase data:

    $ hg showconfig ui | grep log
    ui.logtemplate="{node|short} ({phase}): {desc}\n"

Improved git format diff:

    $ hg showconfig diff
    diff.git=1

And of course, we enable the experimental extensions for mutable history:

    $ cat >> $HGRCPATH <<EOF
    > [extensions]
    > evolve = $TESTDIR/../hgext3rd/evolve/
    > # enabling rebase is also needed for now
    > rebase =
    > EOF

### Single Developer Usage

This tutorial shows how to use evolution to rewrite history locally.

## Fixing mistake with hg amend

We are versioning a shopping list

    $ cd local
    $ cat  >> shopping << EOF
    > Spam
    > Whizzo butter
    > Albatross
    > Rat (rather a lot)
    > Jugged fish
    > Blancmange
    > Salmon mousse
    > EOF
    $ hg commit -A -m "Monthy Python Shopping list"
    adding shopping

Its first version is shared with the outside.

    $ hg push remote
    pushing to $TESTTMP/remote (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 1 changesets with 1 changes to 1 files

Later I add additional items to my list

    $ cat >> shopping << EOF
    > Egg
    > Sugar
    > Vinegar
    > Oil
    > EOF
    $ hg commit -m "adding condiment"
    $ cat >> shopping << EOF
    > Bananos
    > Pear
    > Apple
    > EOF
    $ hg commit -m "adding fruit"

The history is completely linear so far

    $ hg log -G
    @  4296f0622469 (draft): adding fruit
    |
    o  63ae8c44f4b6 (draft): adding condiment
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 1 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=1, pin=true, pos="1,1!", shape=pentagon, style=filled, width=1]; 0 -> 1 [arrowhead=none, penwidth=2.0]; 2 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=2, pin=true, pos="1,2!", shape=pentagon, style=filled, width=1]; 1 -> 2 [arrowhead=none, penwidth=2.0]; }

But a typo was made in Bananas!

    $ hg export tip
    # HG changeset patch
    # User test
    # Date 0 0
    #      Thu Jan 01 00:00:00 1970 +0000
    # Node ID 4296f0622469c1527d5dc020cf72bd7732c44c64
    # Parent  63ae8c44f4b6274d5580b4eea41a87623301c3e9
    adding fruit

    diff --git a/shopping b/shopping
    --- a/shopping
    +++ b/shopping
    @@ -9,3 +9,6 @@
     Sugar
     Vinegar
     Oil
    +Bananos
    +Pear
    +Apple

The faulty changeset is in the “draft” phase because it has not been exchanged with the outside yet. The first one has been exchanged and is “public” (immutable).

    $ hg log -G
    @  4296f0622469 (draft): adding fruit
    |
    o  63ae8c44f4b6 (draft): adding condiment
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 1 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=1, pin=true, pos="1,1!", shape=pentagon, style=filled, width=1]; 0 -> 1 [arrowhead=none, penwidth=2.0]; 2 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=2, pin=true, pos="1,2!", shape=pentagon, style=filled, width=1]; 1 -> 2 [arrowhead=none, penwidth=2.0]; }

Luckily, I can use hg commit –amend to rewrite my faulty changeset!

    $ sed -i'' -e s/Bananos/Banana/ shopping
    $ hg diff
    diff --git a/shopping b/shopping
    --- a/shopping
    +++ b/shopping
    @@ -9,6 +9,6 @@
     Sugar
     Vinegar
     Oil
    -Bananos
    +Banana
     Pear
     Apple
    $ hg commit --amend

A new changeset with the correct changes replaces the old one.

    $ hg log -G
    @  6445b365ad1c (draft): adding fruit
    |
    o  63ae8c44f4b6 (draft): adding condiment
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 1 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=1, pin=true, pos="1,1!", shape=pentagon, style=filled, width=1]; 0 -> 1 [arrowhead=none, penwidth=2.0]; 3 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=3, pin=true, pos="1,3!", shape=pentagon, style=filled, width=1]; 1 -> 3 [arrowhead=none, penwidth=2.0]; }

    $ hg export tip
    # HG changeset patch
    # User test
    # Date 0 0
    #      Thu Jan 01 00:00:00 1970 +0000
    # Node ID 6445b365ad1c4905e7a120e45242d9f4b51ec48f
    # Parent  63ae8c44f4b6274d5580b4eea41a87623301c3e9
    adding fruit

    diff --git a/shopping b/shopping
    --- a/shopping
    +++ b/shopping
    @@ -9,3 +9,6 @@
     Sugar
     Vinegar
     Oil
    +Banana
    +Pear
    +Apple

## Getting rid of branchy history

While I was working on my list, someone made a change remotely.

    $ cd ../remote
    $ hg up -q
    $ sed -i'' -e 's/Spam/Spam Spam Spam/' shopping
    $ hg ci -m 'SPAM'
    $ cd ../local

I’ll get this remote changeset when pulling

    $ hg pull remote
    pulling from $TESTTMP/remote (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 1 changesets with 1 changes to 1 files (+1 heads)
    new changesets 9ca060c80d74
    (run 'hg heads' to see heads, 'hg merge' to merge)

I now have a new head. Note that this remote head is immutable.

    $ hg log -G
    o  9ca060c80d74 (public): SPAM
    |
    | @  6445b365ad1c (draft): adding fruit
    | |
    | o  63ae8c44f4b6 (draft): adding condiment
    |/
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 1 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=1, pin=true, pos="1,1!", shape=pentagon, style=filled, width=1]; 0 -> 1 [arrowhead=none, penwidth=2.0]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 3 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=3, pin=true, pos="1,3!", shape=pentagon, style=filled, width=1]; 1 -> 3 [arrowhead=none, penwidth=2.0]; }

Instead of merging my head with the new one. I’m going to rebase my work

    $ hg diff
    $ hg rebase --dest 9ca060c80d74 --source 63ae8c44f4b6
    rebasing 1:63ae8c44f4b6 "adding condiment"
    merging shopping
    rebasing 3:6445b365ad1c "adding fruit"
    merging shopping

My local work is now rebased on the remote one.

    $ hg log -G
    @  d300c8f961ce (draft): adding fruit
    |
    o  723e5a43d6d9 (draft): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=pentagon, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=pentagon, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; }

## Removing changesets

I add new items to my list.

    $ cat >> shopping << EOF
    > car
    > bus
    > plane
    > boat
    > EOF
    $ hg ci -m 'transport'
    $ hg log -G
    @  7f938a07ecb2 (draft): transport
    |
    o  d300c8f961ce (draft): adding fruit
    |
    o  723e5a43d6d9 (draft): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

I have a new commit but I realize that don’t want it. (Transport shopping list does not fit well in my standard shopping list)

    $ hg prune . # "." is for working directory parent
    1 files updated, 0 files merged, 0 files removed, 0 files unresolved
    working directory is now at d300c8f961ce
    1 changesets pruned

The silly changeset is gone.

    $ hg log -G
    @  d300c8f961ce (draft): adding fruit
    |
    o  723e5a43d6d9 (draft): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=pentagon, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=pentagon, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; }

## Reordering changesets

We create two changesets.

    $ cat >> shopping << EOF
    > Shampoo
    > Toothbrush
    > ... More bathroom stuff to come
    > Towel
    > Soap
    > EOF
    $ hg ci -m 'bathroom stuff'

    $ sed -i'' -e 's/Spam/Spam Spam Spam/g' shopping
    $ hg ci -m 'SPAM SPAM'
    $ hg log -G
    @  1c877d31b53f (draft): SPAM SPAM
    |
    o  d1928babc208 (draft): bathroom stuff
    |
    o  d300c8f961ce (draft): adding fruit
    |
    o  723e5a43d6d9 (draft): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

Note

We can’t amend changeset 7e82d3f3c2cb or 9ca060c80d74 as they are immutable.

I now want to push to remote all my changes except the bathroom one, which I’m not totally happy with yet. To be able to push “SPAM SPAM” I need a version of “SPAM SPAM” which is not a child of “bathroom stuff”.

You can use the ‘grab’ command for that.

Note

grab is an alias for hg rebase –dest . –rev <target>; hg up <result>

    $ hg up 'p1(d1928babc208)' # going on "bathroom stuff" parent
    1 files updated, 0 files merged, 0 files removed, 0 files unresolved
    $ hg pick 1c877d31b53f # moving "SPAM SPAM" to the working directory parent
    picking 9:1c877d31b53f "SPAM SPAM"
    merging shopping
    $ hg log -G
    @  501b33037995 (draft): SPAM SPAM
    |
    | o  d1928babc208 (draft): bathroom stuff
    |/
    o  d300c8f961ce (draft): adding fruit
    |
    o  723e5a43d6d9 (draft): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=pentagon, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=pentagon, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 8 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=8, pin=true, pos="1,8!", shape=pentagon, style=filled, width=1]; 6 -> 8 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=pentagon, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; }

We have a new version of “SPAM SPAM” without the bathroom stuff

    $ grep Spam shopping  # enough spam
    Spam Spam Spam Spam Spam Spam Spam Spam Spam
    $ grep Toothbrush shopping # no Toothbrush
    [1]
    $ hg export .
    # HG changeset patch
    # User test
    # Date 0 0
    #      Thu Jan 01 00:00:00 1970 +0000
    # Node ID 501b330379955b6bf194dc99504a477b1f2d3f89
    # Parent  d300c8f961ceefede93601dbe478c701e2ff5995
    SPAM SPAM

    diff --git a/shopping b/shopping
    --- a/shopping
    +++ b/shopping
    @@ -1,4 +1,4 @@
    -Spam Spam Spam
    +Spam Spam Spam Spam Spam Spam Spam Spam Spam
     Whizzo butter
     Albatross
     Rat (rather a lot)

To make sure I do not push unfinished changeset by mistake I move the “bathroom stuff” changeset to the secret phase.

    $ hg phase --force --secret d1928babc208

we can now push our change:

    $ hg push remote
    pushing to $TESTTMP/remote (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 3 changesets with 3 changes to 1 files
    5 new obsolescence markers

for simplicity’s sake we get the bathroom change in line again

    $ hg pick d1928babc208
    picking 8:d1928babc208 "bathroom stuff"
    merging shopping
    $ hg phase --draft .
    $ hg log -G
    @  39b19dc3d1e4 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 11 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=11, pin=true, pos="1,11!", shape=pentagon, style=filled, width=1]; 10 -> 11 [arrowhead=none, penwidth=2.0]; }

## Splitting change

This part is not written yet, but you can use either the histedit extension or the uncommit command to split a change.

    $ hg help uncommit
    hg uncommit [OPTION]... [FILE]...

    move changes from parent revision to working directory

    Changes to selected files in the checked out revision appear again as
    uncommitted changed in the working directory. A new revision without the
    selected changes is created, becomes the checked out revision, and obsoletes
    the previous one.

    The --include option specifies patterns to uncommit. The --exclude option
    specifies patterns to keep in the commit.

    The --rev argument let you change the commit file to a content of another
    revision. It still does not change the content of your file in the working
    directory.

    Return 0 if changed files are uncommitted.

    options ([+] can be repeated):

     -a --all                 uncommit all changes when no arguments given
     -r --rev REV             revert commit content to REV instead
        --revert              discard working directory changes after uncommit
     -n --note TEXT           store a note on uncommit
     -I --include PATTERN [+] include names matching the given patterns
     -X --exclude PATTERN [+] exclude names matching the given patterns
     -m --message TEXT        use text as commit message
     -l --logfile FILE        read commit message from file
     -d --date DATE           record the specified date as commit date
     -u --user USER           record the specified user as committer
     -D --current-date        record the current date as commit date
     -U --current-user        record the current user as committer

    (some details hidden, use --verbose to show complete help)

The edit command of histedit can be used to split changeset:

## Collapsing change

The tutorial part is not written yet but can use hg fold:

    $ hg help fold
    hg fold [OPTION]... [-r] REV...

    aliases: squash

    fold multiple revisions into a single one

    With --from, folds all the revisions linearly between the given revisions and
    the parent of the working directory.

    With --exact, folds only the specified revisions while ignoring the parent of
    the working directory. In this case, the given revisions must form a linear
    unbroken chain.

    options ([+] can be repeated):

     -r --rev REV [+]  revision to fold
        --exact        only fold specified revisions
        --from         fold revisions linearly to working copy parent
     -n --note TEXT    store a note on fold
     -m --message TEXT use text as commit message
     -l --logfile FILE read commit message from file
     -d --date DATE    record the specified date as commit date
     -u --user USER    record the specified user as committer
     -D --current-date record the current date as commit date
     -U --current-user record the current user as committer

    (some details hidden, use --verbose to show complete help)

### Collaboration

## Sharing mutable changesets

To share mutable changesets with others, just check that the repo you interact with is “not publishing”. Otherwise you will get the previously observe behavior where exchanged changeset are automatically published.

    $ cd ../remote
    $ hg -R ../local/ showconfig phases
    [1]

The local repo does not have any specific configuration for phases.publish. It is `true` by default.

    $ hg pull local
    pulling from $TESTTMP/local (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 1 changesets with 1 changes to 1 files
    1 new obsolescence markers
    new changesets 39b19dc3d1e4
    (run 'hg update' to get a working copy)
    $ hg log -G
    o  39b19dc3d1e4 (public): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    @  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

We do not want to publish the “bathroom changeset”. Let’s rollback the last transaction.

Warning

rollback is actually a dangerous kind of internal command that is deprecated and should not be exposed to user. Please forget you read about it until someone fix this tutorial.

    $ hg rollback
    repository tip rolled back to revision 4 (undo pull)
    $ hg log -G
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    @  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

Let’s make the local repo “non publishing”.

    $ echo '[phases]' >> ../local/.hg/hgrc
    $ echo 'publish=false' >> ../local/.hg/hgrc
    $ echo '[phases]' >> .hg/hgrc
    $ echo 'publish=false' >> .hg/hgrc
    $ hg showconfig phases
    phases.publish=false
    $ hg -R ../local/ showconfig phases
    phases.publish=false

I can now exchange mutable changeset between “remote” and “local” repository.

    $ hg pull local
    pulling from $TESTTMP/local (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 1 changesets with 1 changes to 1 files
    1 new obsolescence markers
    new changesets 39b19dc3d1e4 (1 drafts)
    (run 'hg update' to get a working copy)
    $ hg log -G
    o  39b19dc3d1e4 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    @  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

## Rebasing unstable change after pull

Remotely someone add a new changeset on top of the mutable “bathroom” on.

    $ hg up 39b19dc3d1e4 -q
    $ cat >> shopping << EOF
    > Giraffe
    > Rhino
    > Lion
    > Bear
    > EOF
    $ hg ci -m 'animals'

But at the same time, locally, this same “bathroom changeset” was updated.

    $ cd ../local
    $ hg up 39b19dc3d1e4 -q
    $ sed -i'' -e 's/... More bathroom stuff to come/Bath Robe/' shopping
    $ hg commit --amend
    $ hg log -G
    @  5486682f4225 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 12 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=12, pin=true, pos="1,12!", shape=pentagon, style=filled, width=1]; 10 -> 12 [arrowhead=none, penwidth=2.0]; }

When we pull from remote again we get an unstable state!

    $ hg pull remote
    pulling from $TESTTMP/remote (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 1 changesets with 1 changes to 1 files
    1 new orphan changesets
    new changesets 0609f95eccab (1 drafts)
    (run 'hg update' to get a working copy)

The new changeset “animal” is based on an old changeset of “bathroom”. You can see both version showing up in the log.

    $ hg log -G
    *  0609f95eccab (draft): animals
    |
    | @  5486682f4225 (draft): bathroom stuff
    | |
    x |  39b19dc3d1e4 (draft): bathroom stuff
    |/
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 11 [fillcolor="#DFDFFF", fixedsize=true, group=default_alt, height=1, label=11, pin=true, pos="2,11!", shape=pentagon, style="dotted, filled", width=1]; 10 -> 11 [arrowhead=none, penwidth=2.0]; 12 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=12, pin=true, pos="1,12!", shape=pentagon, style=filled, width=1]; 10 -> 12 [arrowhead=none, penwidth=2.0]; 11 -> 12 [arrowtail=none, dir=back, minlen=0, penwidth=2.0, style=dashed]; 13 [fillcolor="#FF4F4F", fixedsize=true, group=default_alt, height=1, label=13, pin=true, pos="2,13!", shape=pentagon, style=filled, width=1]; 11 -> 13 [arrowhead=none, penwidth=2.0]; }

The older version 39b19dc3d1e4 never ceased to exist in the local repo. It was just hidden and excluded from pull and push.

Note

In hgview there is a nice dotted relation highlighting 5486682f4225 as a new version of 39b19dc3d1e4. This is not yet ported to `hg log -G`.

There is now an unstable changeset in this history. Mercurial will refuse to share it with the outside:

    $ hg push other
    pushing to $TESTTMP/other (glob)
    searching for changes
    abort: push includes orphan changeset: 0609f95eccab!
    (use 'hg evolve' to get a stable history or --force to ignore warnings)
    [255]

To resolve this unstable state, you need to rebase 0609f95eccab onto 5486682f4225. The hg evolve command will do this for you.

It has a –dry-run option to only suggest the next move.

    $ hg evolve --dry-run
    move:[13] animals
    atop:[12] bathroom stuff
    hg rebase -r 0609f95eccab -d 5486682f4225

Let’s do it

    $ hg evolve
    move:[13] animals
    atop:[12] bathroom stuff
    merging shopping

The old version of bathroom is hidden again.

    $ hg log -G
    o  3266db1117c9 (draft): animals
    |
    @  5486682f4225 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

And let’s update to the newly evolved changeset.

    $ hg update
    1 files updated, 0 files merged, 0 files removed, 0 files unresolved

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 12 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=12, pin=true, pos="1,12!", shape=pentagon, style=filled, width=1]; 10 -> 12 [arrowhead=none, penwidth=2.0]; 14 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=14, pin=true, pos="1,14!", shape=pentagon, style=filled, width=1]; 12 -> 14 [arrowhead=none, penwidth=2.0]; }

We can push this evolution to remote.

    $ hg push remote
    pushing to $TESTTMP/remote (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 2 changesets with 2 changes to 1 files (+1 heads)
    2 new obsolescence markers
    obsoleted 2 changesets

Remote get a warning that current working directory is based on an obsolete changeset.

    $ cd ../remote
    $ hg pull local # we up again to trigger the warning. it was displayed during the push
    pulling from $TESTTMP/local (glob)
    searching for changes
    no changes found

Now let’s see where we are, and update to the successor.

    $ hg parents
    0609f95eccab (draft): animals
    working directory parent is obsolete! (0609f95eccab)
    (use 'hg evolve' to update to its successor: 3266db1117c9)
    $ hg evolve
    update:[8] animals
    1 files updated, 0 files merged, 0 files removed, 0 files unresolved
    working directory is now at 3266db1117c9

## Relocating unstable change after prune

The remote guy keeps working.

    $ sed -i'' -e 's/Spam/Spam Spam Spam Spam/g' shopping
    $ hg commit -m "SPAM SPAM SPAM"

I’m pulling its work locally.

    $ cd ../local
    $ hg pull remote
    pulling from $TESTTMP/remote (glob)
    searching for changes
    adding changesets
    adding manifests
    adding file changes
    added 1 changesets with 1 changes to 1 files
    new changesets fff8c3d068b6 (1 drafts)
    (run 'hg update' to get a working copy)
    $ hg log -G
    o  fff8c3d068b6 (draft): SPAM SPAM SPAM
    |
    @  3266db1117c9 (draft): animals
    |
    o  5486682f4225 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 12 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=12, pin=true, pos="1,12!", shape=pentagon, style=filled, width=1]; 10 -> 12 [arrowhead=none, penwidth=2.0]; 14 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=14, pin=true, pos="1,14!", shape=pentagon, style=filled, width=1]; 12 -> 14 [arrowhead=none, penwidth=2.0]; 15 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=15, pin=true, pos="1,15!", shape=pentagon, style=filled, width=1]; 14 -> 15 [arrowhead=none, penwidth=2.0]; }

In the mean time I noticed you can’t buy animals in a super market and I prune the animal changeset:

    $ hg prune 3266db1117c9
    1 files updated, 0 files merged, 0 files removed, 0 files unresolved
    working directory is now at 5486682f4225
    1 changesets pruned
    1 new orphan changesets

The animals changeset is still displayed because the “SPAM SPAM SPAM” changeset is neither dead or obsolete. My repository is in an unstable state again.

    $ hg log -G
    *  fff8c3d068b6 (draft): SPAM SPAM SPAM
    |
    x  3266db1117c9 (draft): animals
    |
    @  5486682f4225 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 12 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=12, pin=true, pos="1,12!", shape=pentagon, style=filled, width=1]; 10 -> 12 [arrowhead=none, penwidth=2.0]; 14 [fillcolor="#DFDFFF", fixedsize=true, group=default_alt, height=1, label=14, pin=true, pos="2,14!", shape=pentagon, style="dotted, filled", width=1]; 12 -> 14 [arrowhead=none, penwidth=2.0]; 15 [fillcolor="#FF4F4F", fixedsize=true, group=default_alt, height=1, label=15, pin=true, pos="2,15!", shape=pentagon, style=filled, width=1]; 14 -> 15 [arrowhead=none, penwidth=2.0]; }

    $ hg log -r "orphan()"
    fff8c3d068b6 (draft): SPAM SPAM SPAM

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 15 [fillcolor="#FF4F4F", fixedsize=true, group=default_alt, height=1, label=15, pin=true, pos="1,15!", shape=pentagon, style=filled, width=1]; }

The –update flag of hg evolve automatically updates to the tipmost evolved changeset.

    $ hg evolve --update
    move:[15] SPAM SPAM SPAM
    atop:[12] bathroom stuff
    merging shopping
    working directory is now at c33e56ec23a8

    $ hg log -G
    @  c33e56ec23a8 (draft): SPAM SPAM SPAM
    |
    o  5486682f4225 (draft): bathroom stuff
    |
    o  501b33037995 (public): SPAM SPAM
    |
    o  d300c8f961ce (public): adding fruit
    |
    o  723e5a43d6d9 (public): adding condiment
    |
    o  9ca060c80d74 (public): SPAM
    |
    o  7e82d3f3c2cb (public): Monthy Python Shopping list

strict digraph "Mercurial graph" { graph [rankdir=LR, splines=polyline ]; node [label="\N"]; 0 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=0, pin=true, pos="1,0!", shape=circle, style=filled, width=1]; 4 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=4, pin=true, pos="1,4!", shape=circle, style=filled, width=1]; 0 -> 4 [arrowhead=none, penwidth=2.0]; 5 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=5, pin=true, pos="1,5!", shape=circle, style=filled, width=1]; 4 -> 5 [arrowhead=none, penwidth=2.0]; 6 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=6, pin=true, pos="1,6!", shape=circle, style=filled, width=1]; 5 -> 6 [arrowhead=none, penwidth=2.0]; 10 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=10, pin=true, pos="1,10!", shape=circle, style=filled, width=1]; 6 -> 10 [arrowhead=none, penwidth=2.0]; 12 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=12, pin=true, pos="1,12!", shape=pentagon, style=filled, width=1]; 10 -> 12 [arrowhead=none, penwidth=2.0]; 16 [fillcolor="#7F7FFF", fixedsize=true, group=default, height=1, label=16, pin=true, pos="1,16!", shape=pentagon, style=filled, width=1]; 12 -> 16 [arrowhead=none, penwidth=2.0]; }

## Handling Divergent amend

We can detect that multiple diverging amendments have been made. The evolve command can solve this situation. But all corner case are not handled now.

This section needs to be written.