evolve: create a new commit instead of amending one of the divergents
This patch changes the behavior of evolve command while resolving
content-divergence to create a new commit instead of amending one of the
divergent ones.
In past, I have made this change, backed out this change and now today again I
am doing this change, so let's dive in some history.
Using cmdrewrite.amend() was never a good option as that requires hack to delete
the evolvestate and also gives us less control over things. We can't make the
commit on top of different parents as that of content-divergent ones. Due to all
these, I first made this change to create a new commit instead of amending one.
But, after few days, there was flakiness observed in the tests and turned out
that we need to do some dirstate dance as repo.dirstate.setparents() does not
always fix the dirstate. That flakiness was a blocker for progress at that time
and we decided to switch to amend back so that we can have things working with
some hacks and we can later fix the implementation part.
Now, yesterday while tackling resolving content-divergence of a stack which is
as follows:
C1 C2
| |
B1 B2
| |
A1 A2
\/
base
where, A1-A2, B1-B2, C1-C2 are content-divergent with each other. Now we can
resolve A1-A2 very well because they have the same parent and let's say that
resolution leads to A3.
Now, we want to resolve B1-B2 and make the new resolution commit on top of A3 so
that we can end up something like:
C3
|
B3
|
A3
|
base
however, amending one of the divergent changesets, it's not possible to create a
commit on a different parent like A3 here without some relocation. We should
prevent relocation as that may leads to some conflicts and should change the
parent before committing.
So, looking ahead, we can't move with using amend as still using that we will
need some relocation hacks making code ugly and prone to bad behaviors, bugs.
Let's change back to creating a new commit so that we can move forward in a good
way.
About repo.dirstate.setparents() not setting the dirstate, I have researched
yesterday night about how we can do that and found out that we can use
cmdrewrite._uncommitdirstate() here. Expect upcoming patches to improve the
documentation of that function.
There are lot of test changes because of change in hash but there is no behavior
change. The only behavior change is in test-evolve-abort-contentdiv.t which is
nice because creating a new commit helps us in stripping that while aborting.
We have a lot of testing of content-divergence and no behavior change gives
enough confidence for making this change.
I reviewed the patch carefully to make sure there is no behavior change and I
suggest reviewer to do the same.
Test script based on sharing.rst: ensure that all scenarios in that
document work as advertised.
Setting things up
$ cat >> $HGRCPATH <<EOF
> [alias]
> shortlog = log --template '{rev}:{node|short} {phase} {desc|firstline}\n'
> [extensions]
> rebase =
> EOF
$ echo "evolve=$(echo $(dirname $TESTDIR))/hgext3rd/evolve/" >> $HGRCPATH
$ hg init public
$ hg clone public test-repo
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone test-repo dev-repo
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat >> test-repo/.hg/hgrc <<EOF
> [phases]
> publish = false
> EOF
To start things off, let's make one public, immutable changeset::
$ cd test-repo
$ echo 'my new project' > file1
$ hg add file1
$ hg commit -m'create new project'
$ hg push
pushing to $TESTTMP/public (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
and pull that into the development repository::
$ cd ../dev-repo
$ hg pull -u
pulling from $TESTTMP/test-repo (glob)
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 0dc9c9f6ab91
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Let's commit a preliminary change and push it to ``test-repo`` for
testing. ::
$ echo 'fix fix fix' > file1
$ hg commit -m'prelim change'
$ hg push -q ../test-repo
Figure SG01 (roughly)
$ hg shortlog -G
@ 1:f6490818a721 draft prelim change
|
o 0:0dc9c9f6ab91 public create new project
Now let's switch to test-repo to test our change and amend::
$ cd ../test-repo
$ hg update -q
$ echo 'Fix fix fix.' > file1
$ hg amend -m'fix bug 37'
Figure SG02
$ hg shortlog --hidden -G
@ 2:60ffde5765c5 draft fix bug 37
|
| x 1:f6490818a721 draft prelim change
|/
o 0:0dc9c9f6ab91 public create new project
Pull into dev-repo: obsolescence markers are transferred, but not
the new obsolete changeset.
$ cd ../dev-repo
$ hg pull -u
pulling from $TESTTMP/test-repo (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets
new changesets 60ffde5765c5
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
updated to "60ffde5765c5: fix bug 37"
1 other heads for branch "default"
Figure SG03
$ hg shortlog --hidden -G
@ 2:60ffde5765c5 draft fix bug 37
|
| x 1:f6490818a721 draft prelim change
|/
o 0:0dc9c9f6ab91 public create new project
Amend again in dev-repo
$ echo 'Fix, fix, and fix.' > file1
$ hg amend
$ hg push -q
Figure SG04 (dev-repo)
$ hg shortlog --hidden -G
@ 3:de6151c48e1c draft fix bug 37
|
| x 2:60ffde5765c5 draft fix bug 37
|/
| x 1:f6490818a721 draft prelim change
|/
o 0:0dc9c9f6ab91 public create new project
Figure SG04 (test-repo)
$ cd ../test-repo
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
updated to "de6151c48e1c: fix bug 37"
1 other heads for branch "default"
$ hg shortlog --hidden -G
@ 3:de6151c48e1c draft fix bug 37
|
| x 2:60ffde5765c5 draft fix bug 37
|/
| x 1:f6490818a721 draft prelim change
|/
o 0:0dc9c9f6ab91 public create new project
This bug fix is finished. We can push it to the public repository.
$ hg push
pushing to $TESTTMP/public (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
2 new obsolescence markers
Now that the fix is public, we cannot amend it any more.
$ hg amend -m 'fix bug 37'
abort: cannot amend public changesets: de6151c48e1c
(see 'hg help phases' for details)
[255]
Figure SG05
$ hg -R ../public shortlog -G
o 1:de6151c48e1c public fix bug 37
|
o 0:0dc9c9f6ab91 public create new project
Oops, still have draft changesets in dev-repo: push the phase change there.
$ hg -R ../dev-repo shortlog -r 'draft()'
3:de6151c48e1c draft fix bug 37
$ hg push ../dev-repo
pushing to ../dev-repo
searching for changes
no changes found
[1]
$ hg -R ../dev-repo shortlog -r 'draft()'
Sharing with multiple developers: code review
$ cd ..
$ hg clone public review
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone review alice
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone review bob
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat >> review/.hg/hgrc <<EOF
> [phases]
> publish = false
> EOF
Alice commits a draft bug fix, pushes to review repo.
$ cd alice
$ hg bookmark bug15
$ echo 'fix' > file2
$ hg commit -A -u alice -m 'fix bug 15 (v1)'
adding file2
$ hg push -B bug15
pushing to $TESTTMP/review (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
exporting bookmark bug15
$ hg -R ../review bookmarks
bug15 2:f91e97234c2b
Alice receives code review, amends her fix, and goes out to lunch to
await second review.
$ echo 'Fix.' > file2
$ hg amend -m 'fix bug 15 (v2)'
$ hg push
pushing to $TESTTMP/review (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets
updating bookmark bug15
$ hg -R ../review bookmarks
bug15 3:cbdfbd5a5db2
Figure SG06: review repository after Alice pushes her amended changeset.
$ hg --hidden -R ../review shortlog -G -r 1::
o 3:cbdfbd5a5db2 draft fix bug 15 (v2)
|
| x 2:f91e97234c2b draft fix bug 15 (v1)
|/
@ 1:de6151c48e1c public fix bug 37
|
~
Bob commits a draft changeset, pushes to review repo.
$ cd ../bob
$ echo 'stuff' > file1
$ hg bookmark featureX
$ hg commit -u bob -m 'implement feature X (v1)'
$ hg push -B featureX
pushing to $TESTTMP/review (glob)
searching for changes
remote has heads on branch 'default' that are not known locally: cbdfbd5a5db2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
exporting bookmark featureX
$ hg -R ../review bookmarks
bug15 3:cbdfbd5a5db2
featureX 4:193657d1e852
Bob receives first review, amends and pushes.
$ echo 'do stuff' > file1
$ hg amend -m 'implement feature X (v2)'
$ hg push
pushing to $TESTTMP/review (glob)
searching for changes
remote has heads on branch 'default' that are not known locally: cbdfbd5a5db2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets
updating bookmark featureX
Bob receives second review, amends, and pushes to public:
this time, he's sure he got it right!
$ echo 'Do stuff.' > file1
$ hg amend -m 'implement feature X (v3)'
$ hg push ../public
pushing to ../public
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
2 new obsolescence markers
$ hg -R ../public bookmarks
no bookmarks set
$ hg push ../review
pushing to ../review
searching for changes
remote has heads on branch 'default' that are not known locally: cbdfbd5a5db2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets
updating bookmark featureX
$ hg -R ../review bookmarks
bug15 3:cbdfbd5a5db2
featureX 6:540ba8f317e6
Figure SG07: review and public repos after Bob implements feature X.
$ hg --hidden -R ../review shortlog -G -r 1::
o 6:540ba8f317e6 public implement feature X (v3)
|
| x 5:0eb74a7b6698 draft implement feature X (v2)
|/
| x 4:193657d1e852 draft implement feature X (v1)
|/
| o 3:cbdfbd5a5db2 draft fix bug 15 (v2)
|/
| x 2:f91e97234c2b draft fix bug 15 (v1)
|/
@ 1:de6151c48e1c public fix bug 37
|
~
$ hg --hidden -R ../public shortlog -G -r 1::
o 2:540ba8f317e6 public implement feature X (v3)
|
o 1:de6151c48e1c public fix bug 37
|
~
How do things look in the review repo?
$ cd ../review
$ hg --hidden shortlog -G -r 1::
o 6:540ba8f317e6 public implement feature X (v3)
|
| x 5:0eb74a7b6698 draft implement feature X (v2)
|/
| x 4:193657d1e852 draft implement feature X (v1)
|/
| o 3:cbdfbd5a5db2 draft fix bug 15 (v2)
|/
| x 2:f91e97234c2b draft fix bug 15 (v1)
|/
@ 1:de6151c48e1c public fix bug 37
|
~
Meantime, Alice is back from lunch. While she was away, Bob approved
her change, so now she can publish it.
$ cd ../alice
$ hg --hidden shortlog -G -r 1::
@ 3:cbdfbd5a5db2 draft fix bug 15 (v2)
|
| x 2:f91e97234c2b draft fix bug 15 (v1)
|/
o 1:de6151c48e1c public fix bug 37
|
~
$ hg outgoing -q ../public
3:cbdfbd5a5db2
$ hg push ../public
pushing to ../public
searching for changes
remote has heads on branch 'default' that are not known locally: 540ba8f317e6
abort: push creates new remote head cbdfbd5a5db2 with bookmark 'bug15'!
(pull and merge or see 'hg help push' for details about pushing new heads)
[255]
$ hg pull ../public
pulling from ../public
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
2 new obsolescence markers
new changesets 540ba8f317e6
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg log -G -q -r 'head()'
o 4:540ba8f317e6
|
~
@ 3:cbdfbd5a5db2
|
~
$ hg --hidden shortlog -G -r 1::
o 4:540ba8f317e6 public implement feature X (v3)
|
| @ 3:cbdfbd5a5db2 draft fix bug 15 (v2)
|/
| x 2:f91e97234c2b draft fix bug 15 (v1)
|/
o 1:de6151c48e1c public fix bug 37
|
~
Alice rebases her draft changeset on top of Bob's public changeset and
publishes the result.
$ hg rebase -d 5
rebasing 3:cbdfbd5a5db2 "fix bug 15 (v2)" (bug15)
$ hg push ../public
pushing to ../public
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
2 new obsolescence markers
$ hg push ../review
pushing to ../review
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 1 files
1 new obsolescence markers
obsoleted 1 changesets
updating bookmark bug15
Figure SG08: review and public changesets after Alice pushes.
$ hg --hidden -R ../review shortlog -G -r 1::
o 7:a06ec1bf97bd public fix bug 15 (v2)
|
o 6:540ba8f317e6 public implement feature X (v3)
|
| x 5:0eb74a7b6698 draft implement feature X (v2)
|/
| x 4:193657d1e852 draft implement feature X (v1)
|/
| x 3:cbdfbd5a5db2 draft fix bug 15 (v2)
|/
| x 2:f91e97234c2b draft fix bug 15 (v1)
|/
@ 1:de6151c48e1c public fix bug 37
|
~
$ hg --hidden -R ../public shortlog -G -r 1::
o 3:a06ec1bf97bd public fix bug 15 (v2)
|
o 2:540ba8f317e6 public implement feature X (v3)
|
o 1:de6151c48e1c public fix bug 37
|
~
$ cd ..
Setup for "cowboy mode" shared mutable history (to illustrate divergent
and bumped changesets).
$ rm -rf review alice bob
$ hg clone public alice
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone public bob
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat >> alice/.hg/hgrc <<EOF
> [phases]
> publish = false
> EOF
$ cp alice/.hg/hgrc bob/.hg/hgrc
Now we'll have Bob commit a bug fix that could still be improved::
$ cd bob
$ echo 'pretty good fix' >> file1
$ hg commit -u bob -m 'fix bug 24 (v1)'
$ hg shortlog -r .
4:2fe6c4bd32d0 draft fix bug 24 (v1)
Since Alice and Bob are now in cowboy mode, Alice pulls Bob's draft
changeset and amends it herself. ::
$ cd ../alice
$ hg pull -u ../bob
pulling from ../bob
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 2fe6c4bd32d0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo 'better fix (alice)' >> file1
$ hg amend -u alice -m 'fix bug 24 (v2 by alice)'
Bob implements a better fix of his own::
$ cd ../bob
$ echo 'better fix (bob)' >> file1
$ hg amend -u bob -m 'fix bug 24 (v2 by bob)'
$ hg --hidden shortlog -G -r 3::
@ 5:a360947f6faf draft fix bug 24 (v2 by bob)
|
| x 4:2fe6c4bd32d0 draft fix bug 24 (v1)
|/
o 3:a06ec1bf97bd public fix bug 15 (v2)
|
~
Bob discovers the divergence.
$ hg pull ../alice
pulling from ../alice
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
1 new obsolescence markers
2 new content-divergent changesets
new changesets e3f99ce9d9cd
(run 'hg heads' to see heads, 'hg merge' to merge)
Figure SG09: multiple heads! divergence! oh my!
$ hg --hidden shortlog -G -r 3::
* 6:e3f99ce9d9cd draft fix bug 24 (v2 by alice)
|
| @ 5:a360947f6faf draft fix bug 24 (v2 by bob)
|/
| x 4:2fe6c4bd32d0 draft fix bug 24 (v1)
|/
o 3:a06ec1bf97bd public fix bug 15 (v2)
|
~
$ hg --hidden shortlog -r 'successors(2fe6)'
5:a360947f6faf draft fix bug 24 (v2 by bob)
6:e3f99ce9d9cd draft fix bug 24 (v2 by alice)
Use evolve to fix the divergence.
$ cat > editor.sh <<EOF
> #!/bin/sh
> cat > \$1 <<ENDOF
> fix bug 24 (v2 by bob)
> ENDOF
> EOF
$ HGEDITOR='sh ./editor.sh' HGMERGE=internal:other hg evolve --content-divergent
merge:[5] fix bug 24 (v2 by bob)
with: [6] fix bug 24 (v2 by alice)
base: [4] fix bug 24 (v1)
merging "other" content-divergent changeset 'e3f99ce9d9cd'
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
working directory is now at 711ede2d7a26
$ hg log -q -r 'contentdivergent()'
Figure SG10: Bob's repository after fixing divergence.
$ hg --hidden shortlog -G -r 3::
@ 7:711ede2d7a26 draft fix bug 24 (v2 by bob)
|
| x 6:e3f99ce9d9cd draft fix bug 24 (v2 by alice)
|/
| x 5:a360947f6faf draft fix bug 24 (v2 by bob)
|/
| x 4:2fe6c4bd32d0 draft fix bug 24 (v1)
|/
o 3:a06ec1bf97bd public fix bug 15 (v2)
|
~
$ hg --hidden shortlog -r 'precursors(711ede2d7a26)'
5:a360947f6faf draft fix bug 24 (v2 by bob)
6:e3f99ce9d9cd draft fix bug 24 (v2 by alice)
$ cat file1
Do stuff.
pretty good fix
better fix (alice)