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.
$ cat >> $HGRCPATH <<EOF
> [ui]
> logtemplate={rev}:{node|short} {desc}\n
> [defaults]
> amend=-d "0 0"
> [extensions]
> hgext.rebase=
> EOF
$ echo "evolve=$(echo $(dirname $TESTDIR))/hgext3rd/evolve/" >> $HGRCPATH
$ hg init repo
$ cd repo
$ echo A > a
$ hg add a
$ hg commit -m a
Basic usage
$ hg log -G
@ 0:[0-9a-f]{12} a (re)
$ hg touch .
$ hg log -G
@ 1:[0-9a-f]{12} a (re)
Revive usage
$ echo A > b
$ hg add b
$ hg commit -m ab --amend
$ hg up --hidden 1
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
updated to hidden changeset * (glob)
(hidden revision '*' was rewritten as: *) (glob)
working directory parent is obsolete! (*) (glob)
(use 'hg evolve' to update to its successor: *) (glob)
$ hg log -G
o 2:[0-9a-f]{12} ab (re)
@ 1:[0-9a-f]{12} a (re)
$ hg touch .
[1] a
reviving this changeset will create divergence unless you make a duplicate.
(a)llow divergence or (d)uplicate the changeset? a
2 new content-divergent changesets
$ hg log -G
@ 3:[0-9a-f]{12} a (re)
\* 2:[0-9a-f]{12} ab (re)
$ hg prune 3
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
working directory now at 000000000000
1 changesets pruned
Duplicate
$ hg touch --duplicate .
$ hg log -G
@ 4:[0-9a-f]{12} (re)
o 2:[0-9a-f]{12} ab (re)
Multiple touch
$ echo C > c
$ hg add c
$ hg commit -m c
$ echo D > d
$ hg add d
$ hg commit -m d
$ hg log -G
@ 6:[0-9a-f]{12} d (re)
|
o 5:[0-9a-f]{12} c (re)
|
o 4:[0-9a-f]{12} (re)
o 2:[0-9a-f]{12} ab (re)
$ hg touch .^:.
$ hg log -G
@ 8:[0-9a-f]{12} d (re)
|
o 7:[0-9a-f]{12} c (re)
|
o 4:[0-9a-f]{12} (re)
o 2:[0-9a-f]{12} ab (re)
check move data kept after rebase on touch:
$ touch gna1
$ hg commit -Am gna1
adding gna1
$ hg mv gna1 gna2
$ hg commit -m move
$ hg st -C --change=tip
A gna2
gna1
R gna1
$ hg up .^
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg touch
1 new orphan changesets
$ hg log -G --hidden
@ 11:[0-9a-f]{12} gna1 (re)
|
. \* 10:[0-9a-f]{12} move (re)
| |
. x 9:[0-9a-f]{12} gna1 (re)
|/
o 8:[0-9a-f]{12} d (re)
|
o 7:[0-9a-f]{12} c (re)
|
. x 6:[0-9a-f]{12} d (re)
| |
. x 5:[0-9a-f]{12} c (re)
|/
o 4:[0-9a-f]{12} (re)
x 3:[0-9a-f]{12} a (re)
o 2:[0-9a-f]{12} ab (re)
x 1:[0-9a-f]{12} a (re)
x 0:[0-9a-f]{12} a (re)
$ hg rebase -s 10 -d 11
rebasing 10:[0-9a-f]{12} "move" (re)
$ hg st -C --change=tip
A gna2
gna1
R gna1
check that the --duplicate option does not create divergence
$ hg touch --duplicate 10 --hidden
1 new orphan changesets
check that reviving a changeset with no successor does not show the prompt
$ hg prune 13
1 changesets pruned
$ hg touch 13 --hidden --note "testing with no successor"
1 new orphan changesets
$ hg obslog -r 13 --hidden
x [0-9a-f]{12} (.*) move (re)
pruned using prune by test (Thu Jan 01 00:00:00 1970 +0000)
rewritten(.*) as [0-9a-f]{12} using touch by test (.*) (re)
note: testing with no successor