discovery: filter null from the discovery revset
If there is nothing in common, common will be "null" and the revset will now
returns "-1" crashing the discovery process. We filter out the null revision to
prevent that.
Initial setup
-------------
This Mercurial configuration example is used for testing.
.. Various setup
$ 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
> [alias]
> # "-d '0 0'" means that the new commit will be at January 1st 1970.
> # This is used for stable hash during test
> # (this tutorial is automatically tested.)
> amend = amend -d '0 0'
> 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/../hgext/evolve.py
> # 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 versionning 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 item to my list
$ cat >> shopping << EOF
> Egg
> Suggar
> Vinegar
> Oil
> EOF
$ hg commit -m "adding condiment"
$ cat >> shopping << EOF
> Bananos
> Pear
> Apple
> EOF
$ hg commit -m "adding fruit"
This history is very linear
$ hg log -G
@ d85de4546133 (draft): adding fruit
|
o 4d5dc8187023 (draft): adding condiment
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
But a typo was made in Babanas!
$ hg export tip
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID d85de4546133030c82d257bbcdd9b1b416d0c31c
# Parent 4d5dc81870237d492284826e21840b2ca00e26d1
adding fruit
diff --git a/shopping b/shopping
--- a/shopping
+++ b/shopping
@@ -9,3 +9,6 @@
Suggar
Vinegar
Oil
+Bananos
+Pear
+Apple
The faulty changeset is in the "draft" phase because it has not been exchanged with
the outside. The first one has been exchanged and is "public" (immutable).
$ hg log -G
@ d85de4546133 (draft): adding fruit
|
o 4d5dc8187023 (draft): adding condiment
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
hopefully. 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 @@
Suggar
Vinegar
Oil
-Bananos
+Banana
Pear
Apple
$ hg commit --amend
A new changeset with the right diff replace the wrong one.
$ hg log -G
@ 9d0363b81950 (draft): adding fruit
|
o 4d5dc8187023 (draft): adding condiment
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
$ hg export tip
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID 9d0363b81950646bc6ad1ec5de8b8197ea586541
# Parent 4d5dc81870237d492284826e21840b2ca00e26d1
adding fruit
diff --git a/shopping b/shopping
--- a/shopping
+++ b/shopping
@@ -9,3 +9,6 @@
Suggar
Vinegar
Oil
+Banana
+Pear
+Apple
Getting rid of branchy history
----------------------------------
While I was working on my list. someone made a change remotly.
$ 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)
pull obsolescence markers
(run 'hg heads' to see heads, 'hg merge' to merge)
I now have a new heads. Note that this remote head is immutable
$ hg log -G
o 9ca060c80d74 (public): SPAM
|
| @ 9d0363b81950 (draft): adding fruit
| |
| o 4d5dc8187023 (draft): adding condiment
|/
o 7e82d3f3c2cb (public): Monthy Python Shopping list
instead of merging my head with the new one. I'm going to rebase my work
$ hg diff
$ hg rebase --dest 9ca060c80d74 --source 4d5dc8187023
rebasing 1:4d5dc8187023 "adding condiment"
merging shopping
rebasing 4:9d0363b81950 "adding fruit"
merging shopping
My local work is now rebased on the remote one.
$ hg log -G
@ 41aff6a42b75 (draft): adding fruit
|
o dfd3a2d7691e (draft): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
Removing changesets
------------------------
I add new item to my list
$ cat >> shopping << EOF
> car
> bus
> plane
> boat
> EOF
$ hg ci -m 'transport'
$ hg log -G
@ 1125e39fbf21 (draft): transport
|
o 41aff6a42b75 (draft): adding fruit
|
o dfd3a2d7691e (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 shop list does
not fit well in my standard shopping list)
$ hg prune . # "." is for working directory parent
1 changesets pruned
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
working directory now at 41aff6a42b75
The silly changeset is gone.
$ hg log -G
@ 41aff6a42b75 (draft): adding fruit
|
o dfd3a2d7691e (draft): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
Reordering changesets
------------------------
We create two changesets.
$ cat >> shopping << EOF
> Shampoo
> Toothbrush
> ... More bathroom stuff to come
> Towel
> Soap
> EOF
$ hg ci -m 'bathroom stuff' -q # XXX remove the -q
$ sed -i'' -e 's/Spam/Spam Spam Spam/g' shopping
$ hg ci -m 'SPAM SPAM'
$ hg log -G
@ fac207dec9f5 (draft): SPAM SPAM
|
o 10b8aeaa8cc8 (draft): bathroom stuff
|
o 41aff6a42b75 (draft): adding fruit
|
o dfd3a2d7691e (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' alias for that.
.. note: grab is an alias for `hg rebase --dest . --rev <target>; hg up <there>`
$ hg up 'p1(10b8aeaa8cc8)' # going on "bathroom stuff" parent
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg grab fac207dec9f5 # moving "SPAM SPAM" to the working directory parent
rebasing 10:fac207dec9f5 "SPAM SPAM" (tip)
merging shopping
? files updated, 0 files merged, 0 files removed, 0 files unresolved (glob)
$ hg log -G
@ a224f2a4fb9f (draft): SPAM SPAM
|
| o 10b8aeaa8cc8 (draft): bathroom stuff
|/
o 41aff6a42b75 (draft): adding fruit
|
o dfd3a2d7691e (draft): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
We have a new SPAM SPAM version 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 a224f2a4fb9f9f828f608959912229d7b38b26de
# Parent 41aff6a42b7578ec7ec3cb2041633f1ca43cca96
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 unready changeset by mistake I set the "bathroom
stuff" changeset in the secret phase.
$ hg phase --force --secret 10b8aeaa8cc8
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
pushing 6 obsolescence markers (* bytes) (glob)
6 obsolescence markers added
for simplicity sake we get the bathroom change in line again
$ hg grab 10b8aeaa8cc8
rebasing 9:10b8aeaa8cc8 "bathroom stuff"
merging shopping
? files updated, 0 files merged, 0 files removed, 0 files unresolved (glob)
$ hg phase --draft .
$ hg log -G
@ 75954b8cd933 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
Splitting change
------------------
This part is not written yet, but you can use either the `histedit` extension
of the `uncommit` command to splitting a change.
$ hg help uncommit
hg uncommit [OPTION]... [NAME]
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 VALUE revert commit content to REV instead
-I --include PATTERN [+] include names matching the given patterns
-X --exclude PATTERN [+] exclude names matching the given patterns
(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
Folds a set of revisions with the parent of the working directory. All
revisions linearly between the given revisions and the parent of the
working directory will also be folded.
Use --exact for folding 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 VALUE [+] revision to fold
--exact only fold specified revisions
-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
(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 localrepo 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
pull obsolescence markers
1 obsolescence markers added
(run 'hg update' to get a working copy)
$ hg log -G
o 75954b8cd933 (public): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (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 a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (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
pull obsolescence markers
1 obsolescence markers added
(run 'hg update' to get a working copy)
$ hg log -G
o 75954b8cd933 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (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 75954b8cd933 -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 75954b8cd933 -q
$ sed -i'' -e 's/... More bathroom stuff to come/Bath Robe/' shopping
$ hg commit --amend
$ hg log -G
@ a44c85f957d3 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
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 heads)
pull obsolescence markers
0 obsolescence markers added
(run 'hg heads' to see heads, 'hg merge' to merge)
1 new unstable changesets
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
o bf1b0d202029 (draft): animals
|
| @ a44c85f957d3 (draft): bathroom stuff
| |
x | 75954b8cd933 (draft): bathroom stuff
|/
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
The older version 75954b8cd933 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 a44c85f957d3 as a new version of 75954b8cd933. 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 unstable changeset: bf1b0d202029!
(use 'hg evolve' to get a stable history or --force to ignore warnings)
[255]
To resolve this unstable state, you need to rebase bf1b0d202029 onto
a44c85f957d3. 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:[15] animals
atop:[14] bathroom stuff
hg rebase -r bf1b0d202029 -d a44c85f957d3
Let's do it
$ hg evolve
move:[15] animals
atop:[14] bathroom stuff
merging shopping
working directory is now at ee942144f952
The old version of bathroom is hidden again.
$ hg log -G
@ ee942144f952 (draft): animals
|
o a44c85f957d3 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
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)
pushing 10 obsolescence markers (* bytes) (glob)
3 obsolescence markers added
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
pull obsolescence markers
0 obsolescence markers added
working directory parent is obsolete!
now let's see where we are, and update to the successor
$ hg parents
bf1b0d202029 (draft): animals
working directory parent is obsolete!
$ hg evolve
update:[8] animals
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
working directory is now at ee942144f952
Relocating unstable change after prune
----------------------------------------------
The remote guy keep 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
pull obsolescence markers
0 obsolescence markers added
(run 'hg update' to get a working copy)
$ hg log -G
o 99f039c5ec9e (draft): SPAM SPAM SPAM
|
@ ee942144f952 (draft): animals
|
o a44c85f957d3 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
In the mean time I noticed you can't buy animals in a super market and I prune the animal changeset:
$ hg prune ee942144f952
1 changesets pruned
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
working directory now at a44c85f957d3
1 new unstable 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
o 99f039c5ec9e (draft): SPAM SPAM SPAM
|
x ee942144f952 (draft): animals
|
@ a44c85f957d3 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
$ hg log -r 'unstable()'
99f039c5ec9e (draft): SPAM SPAM SPAM
$ hg evolve
move:[17] SPAM SPAM SPAM
atop:[14] bathroom stuff
merging shopping
working directory is now at 40aa40daeefb
$ hg log -G
@ 40aa40daeefb (draft): SPAM SPAM SPAM
|
o a44c85f957d3 (draft): bathroom stuff
|
o a224f2a4fb9f (public): SPAM SPAM
|
o 41aff6a42b75 (public): adding fruit
|
o dfd3a2d7691e (public): adding condiment
|
o 9ca060c80d74 (public): SPAM
|
o 7e82d3f3c2cb (public): Monthy Python Shopping list
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.