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.
============================================
Testing obsolescence markers push: Cases A.4
============================================
Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of
all changesets that requested to be "in sync" after the push (even if they are
already on both side).
This test belongs to a series of tests checking such set is properly computed
and applied. this does not tests "obsmarkers" discovery capabilities.
Category A: simple cases
Testcase 4: Push in the middle of the obsolescence chain
A.4 Push in the middle of the obsolescence chain
================================================
.. (Where we show that we should not push the marker without the successors)
..
.. {{{
.. B ◔
.. |
.. A⇠ø⇠○ A'
.. |/
.. ● O
.. }}}
..
.. Markers exist from:
..
.. * `A ø⇠○ A'`
.. * chain from A
..
.. Command runs:
..
.. * hg push -r B
..
.. Expected exchange:
..
.. * Chain from A
..
.. Expected Exclude:
..
.. * `Ai ø⇠○ A'`
Setup
-----
$ . $TESTDIR/testlib/exchange-obsmarker-util.sh
initial
$ setuprepos A.4
creating test repo for test case A.4
- pulldest
- main
- pushdest
cd into `main` and proceed with env setup
$ cd main
$ mkcommit A0
$ mkcommit B
$ hg update 0
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ mkcommit A1
created new head
$ hg debugobsolete aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa `getid 'desc(A0)'`
$ hg debugobsolete `getid 'desc(A0)'` `getid 'desc(A1)'`
obsoleted 1 changesets
1 new orphan changesets
$ hg log -G --hidden
@ e5ea8f9c7314 (draft): A1
|
| * 06055a7959d4 (draft): B
| |
| x 28b51eb45704 (draft): A0
|/
o a9bdc8b26820 (public): O
$ inspect_obsmarkers
obsstore content
================
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
obshashtree
===========
a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04 0000000000000000000000000000000000000000
28b51eb45704506b5c603decd6bf7ac5e0f6a52f 5d69322fad9eb1ba8f8f2c2312346ed347fdde76
06055a7959d4128e6e3bccfd01482e83a2db8a3a fd3e5712c9c2d216547d7a1b87ac815ee1fb7542
e5ea8f9c73143125d36658e90ef70c6d2027a5b7 cf518031fa753e9b049d727e6b0e19f645bab38f
obshashrange
============
rev node index size depth obshash
2 06055a7959d4 0 3 3 000000000000
1 28b51eb45704 0 2 2 5d69322fad9e
3 e5ea8f9c7314 0 2 2 cf518031fa75
2 06055a7959d4 2 1 3 000000000000
1 28b51eb45704 1 1 2 5d69322fad9e
0 a9bdc8b26820 0 1 1 000000000000
3 e5ea8f9c7314 1 1 2 cf518031fa75
$ cd ..
$ cd ..
Actual Test for first version
-----------------------------
$ dotest A.4 B -f
## Running testcase A.4
# testing echange of "B" (06055a7959d4)
## initial state
# obstore: main
28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pushdest
# obstore: pulldest
## pushing "B" from main to pushdest
pushing to pushdest
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 2 changesets with 2 changes to 2 files
remote: 1 new obsolescence markers
## post push state
# obstore: main
28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pushdest
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pulldest
## pulling "06055a7959d4" from main into pulldest
pulling from main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
1 new obsolescence markers
new changesets 28b51eb45704:06055a7959d4
(run 'hg update' to get a working copy)
## post pull state
# obstore: main
28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pushdest
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
# obstore: pulldest
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}