annotate tests/test-exchange-obsmarkers-case-B3.t @ 3846:f9dad99a90d5

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 B.3
============================================

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 B: pruning case
TestCase 3: Pruned changeset on non-pushed part of the history

B.3 Pruned changeset on non-pushed part of the history
======================================================

.. {{{
..   ⊗ C
..   |
..   ○ B
..   | ◔ A
..   |/
..   ● O
.. }}}
..
.. Marker exists from:
..
..  * C (prune)
..
.. Commands run:
..
..  * hg push -r A
..
.. Expected exchange:
..
..  * ø
..
.. Expected exclude:
..
..  * chain from B

Setup
-----

  $ . $TESTDIR/testlib/exchange-obsmarker-util.sh

initial

  $ setuprepos B.3
  creating test repo for test case B.3
  - pulldest
  - main
  - pushdest
  cd into `main` and proceed with env setup
  $ cd main
  $ mkcommit A
  $ hg up --quiet 0
  $ mkcommit B
  created new head
  $ mkcommit C
  $ hg prune -qd '0 0' .
  $ hg log -G --hidden
  x  e56289ab6378 (draft): C
  |
  @  35b183996678 (draft): B
  |
  | o  f5bc6836db60 (draft): A
  |/
  o  a9bdc8b26820 (public): O
  
  $ inspect_obsmarkers
  obsstore content
  ================
  e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
  obshashtree
  ===========
  a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04 0000000000000000000000000000000000000000
  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0000000000000000000000000000000000000000
  35b1839966785d5703a01607229eea932db42f87 3bb8cd8ac8f52487f2ef21e0bdf795a5cd293351
  e56289ab6378dc752fd7965f8bf66b58bda740bd b62eedd8d9194225136e5908c492ab03569079da
  obshashrange
  ============
           rev         node        index         size        depth      obshash
             2 35b183996678            0            2            2 3bb8cd8ac8f5
             1 f5bc6836db60            0            2            2 000000000000
             2 35b183996678            1            1            2 3bb8cd8ac8f5
             0 a9bdc8b26820            0            1            1 000000000000
             1 f5bc6836db60            1            1            2 000000000000
  $ cd ..
  $ cd ..

Actual Test
-----------------------------------

  $ dotest B.3 A
  ## Running testcase B.3
  # testing echange of "A" (f5bc6836db60)
  ## initial state
  # obstore: main
  e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
  # obstore: pushdest
  # obstore: pulldest
  ## pushing "A" from main to pushdest
  pushing to pushdest
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  ## post push state
  # obstore: main
  e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
  # obstore: pushdest
  # obstore: pulldest
  ## pulling "f5bc6836db60" from main into pulldest
  pulling from main
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets f5bc6836db60
  (run 'hg update' to get a working copy)
  ## post pull state
  # obstore: main
  e56289ab6378dc752fd7965f8bf66b58bda740bd 0 {35b1839966785d5703a01607229eea932db42f87} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
  # obstore: pushdest
  # obstore: pulldest