view tests/test-evolve-abort-phasediv.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.

Tests for the --abort flag for `hg evolve` command while phase-divergence resolution
====================================================================================

The `--abort` flag aborts the interuppted evolve by undoing all the work which
was done during resolution i.e. stripping new changesets created, moving
bookmarks back, moving working directory back.

This test contains cases when `hg evolve` is doing phase-divergence resolution.

Setup
=====

  $ cat >> $HGRCPATH <<EOF
  > [phases]
  > publish = False
  > [alias]
  > glog = log -GT "{rev}:{node|short} {desc}\n ({bookmarks}) {phase}"
  > [extensions]
  > EOF
  $ echo "evolve=$(echo $(dirname $TESTDIR))/hgext3rd/evolve/" >> $HGRCPATH

  $ hg init abortrepo
  $ cd abortrepo
  $ echo ".*\.orig" > .hgignore
  $ hg add .hgignore
  $ hg ci -m "added hgignore"
  $ for ch in a b c d; do echo foo > $ch; hg add $ch; hg ci -qm "added "$ch; done;

  $ hg glog
  @  4:c41c793e0ef1 added d
  |   () draft
  o  3:ca1b80f7960a added c
  |   () draft
  o  2:b1661037fa25 added b
  |   () draft
  o  1:c7586e2a9264 added a
  |   () draft
  o  0:8fa14d15e168 added hgignore
      () draft

Creating phase divergence, resolution of which will lead to conflicts
----------------------------------------------------------------------

  $ hg up .^^^
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ hg grab -r .~-3
  grabbing 4:c41c793e0ef1 "added d"
  $ echo foobar > c
  $ hg add c
  $ hg amend

  $ hg glog --hidden
  @  6:ddba58020bc0 added d
  |   () draft
  | x  5:cfe30edc6125 added d
  |/    () draft
  | x  4:c41c793e0ef1 added d
  | |   () draft
  | o  3:ca1b80f7960a added c
  | |   () draft
  | o  2:b1661037fa25 added b
  |/    () draft
  o  1:c7586e2a9264 added a
  |   () draft
  o  0:8fa14d15e168 added hgignore
      () draft

  $ hg phase -r c41c793e0ef1 --public --hidden
  1 new phase-divergent changesets

  $ hg glog
  @  6:ddba58020bc0 added d
  |   () draft
  | o  4:c41c793e0ef1 added d
  | |   () public
  | o  3:ca1b80f7960a added c
  | |   () public
  | o  2:b1661037fa25 added b
  |/    () public
  o  1:c7586e2a9264 added a
  |   () public
  o  0:8fa14d15e168 added hgignore
      () public
  $ hg evolve --phase-divergent
  recreate:[6] added d
  atop:[4] added d
  rebasing to destination parent: ca1b80f7960a
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  abort: fix conflicts and see `hg help evolve.interrupted`
  [255]

testing that interrupted evolve shows up in morestatus
  $ hg status -v
  M c
  A d
  # The repository is in an unfinished *evolve* state.
  
  # Unresolved merge conflicts:
  # 
  #     c
  # 
  # To mark files as resolved:  hg resolve --mark FILE
  
  # To continue:    hg evolve --continue
  # To abort:       hg evolve --abort
  # To stop:        hg evolve --stop
  # (also see `hg help evolve.interrupted`)
  

  $ hg evolve --abort
  evolve aborted
  working directory is now at ddba58020bc0

  $ hg glog
  @  6:ddba58020bc0 added d
  |   () draft
  | o  4:c41c793e0ef1 added d
  | |   () public
  | o  3:ca1b80f7960a added c
  | |   () public
  | o  2:b1661037fa25 added b
  |/    () public
  o  1:c7586e2a9264 added a
  |   () public
  o  0:8fa14d15e168 added hgignore
      () public

When there are multiple phase-divergent changes, resolution of last one resulted
in conflicts
---------------------------------------------------------------------------------

  $ echo foo > c
  $ hg amend
  $ hg phase -r ca1b80f --draft --force
  $ hg prev
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  [1] added a
  $ hg grab -r ca1b80f
  grabbing 3:ca1b80f7960a "added c"
  $ echo foobar > b
  $ hg add b
  $ hg amend
  $ hg phase -r c41c793e0ef1 --public --hidden
  2 new phase-divergent changesets

  $ hg evolve --list
  e44ebefe4f54: added d
    phase-divergent: c41c793e0ef1 (immutable precursor)
  
  28cd06b3f801: added c
    phase-divergent: ca1b80f7960a (immutable precursor)
  

  $ hg evolve --dry-run --all --phase-divergent
  recreate:[7] added d
  atop:[4] added d
  hg rebase --rev e44ebefe4f54 --dest ca1b80f7960a;
  hg update c41c793e0ef1;
  hg revert --all --rev e44ebefe4f54;
  hg commit --msg "phase-divergent update to e44ebefe4f54"
  recreate:[9] added c
  atop:[3] added c
  hg rebase --rev 28cd06b3f801 --dest b1661037fa25;
  hg update ca1b80f7960a;
  hg revert --all --rev 28cd06b3f801;
  hg commit --msg "phase-divergent update to 28cd06b3f801"

  $ hg glog --hidden
  @  9:28cd06b3f801 added c
  |   () draft
  | x  8:9ff8adbe8a24 added c
  |/    () draft
  | *  7:e44ebefe4f54 added d
  |/    () draft
  | x  6:ddba58020bc0 added d
  |/    () draft
  | x  5:cfe30edc6125 added d
  |/    () draft
  | o  4:c41c793e0ef1 added d
  | |   () public
  | o  3:ca1b80f7960a added c
  | |   () public
  | o  2:b1661037fa25 added b
  |/    () public
  o  1:c7586e2a9264 added a
  |   () public
  o  0:8fa14d15e168 added hgignore
      () public

  $ hg evolve --phase-divergent --all
  recreate:[7] added d
  atop:[4] added d
  rebasing to destination parent: ca1b80f7960a
  computing new diff
  committed as c41c793e0ef1
  recreate:[9] added c
  atop:[3] added c
  rebasing to destination parent: b1661037fa25
  merging b
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  abort: fix conflicts and see `hg help evolve.interrupted`
  [255]

  $ hg evolve --abort
  1 new phase-divergent changesets
  evolve aborted
  working directory is now at 28cd06b3f801

  $ hg glog --hidden
  @  9:28cd06b3f801 added c
  |   () draft
  | x  8:9ff8adbe8a24 added c
  |/    () draft
  | *  7:e44ebefe4f54 added d
  |/    () draft
  | x  6:ddba58020bc0 added d
  |/    () draft
  | x  5:cfe30edc6125 added d
  |/    () draft
  | o  4:c41c793e0ef1 added d
  | |   () public
  | o  3:ca1b80f7960a added c
  | |   () public
  | o  2:b1661037fa25 added b
  |/    () public
  o  1:c7586e2a9264 added a
  |   () public
  o  0:8fa14d15e168 added hgignore
      () public

When there are multiple conflicted phase-divergence resolution and we abort
after resolving one of them
----------------------------------------------------------------------------

  $ hg up e44ebefe4f54
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo foobar > c
  $ hg amend

  $ hg glog --hidden
  @  10:ef9b72b9b42c added d
  |   () draft
  | *  9:28cd06b3f801 added c
  |/    () draft
  | x  8:9ff8adbe8a24 added c
  |/    () draft
  | x  7:e44ebefe4f54 added d
  |/    () draft
  | x  6:ddba58020bc0 added d
  |/    () draft
  | x  5:cfe30edc6125 added d
  |/    () draft
  | o  4:c41c793e0ef1 added d
  | |   () public
  | o  3:ca1b80f7960a added c
  | |   () public
  | o  2:b1661037fa25 added b
  |/    () public
  o  1:c7586e2a9264 added a
  |   () public
  o  0:8fa14d15e168 added hgignore
      () public

  $ hg evolve --phase-divergent --all
  recreate:[9] added c
  atop:[3] added c
  rebasing to destination parent: b1661037fa25
  merging b
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  abort: fix conflicts and see `hg help evolve.interrupted`
  [255]

  $ echo watwat > c
  $ hg resolve -m
  (no more unresolved files)
  continue: hg evolve --continue
  $ hg evolve --continue
  evolving 9:28cd06b3f801 "added c"
  computing new diff
  committed as 95d746965290
  recreate:[10] added d
  atop:[4] added d
  rebasing to destination parent: ca1b80f7960a
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  abort: fix conflicts and see `hg help evolve.interrupted`
  [255]

  $ hg evolve --abort
  1 new phase-divergent changesets
  evolve aborted
  working directory is now at ef9b72b9b42c

  $ hg glog --hidden
  @  10:ef9b72b9b42c added d
  |   () draft
  | *  9:28cd06b3f801 added c
  |/    () draft
  | x  8:9ff8adbe8a24 added c
  |/    () draft
  | x  7:e44ebefe4f54 added d
  |/    () draft
  | x  6:ddba58020bc0 added d
  |/    () draft
  | x  5:cfe30edc6125 added d
  |/    () draft
  | o  4:c41c793e0ef1 added d
  | |   () public
  | o  3:ca1b80f7960a added c
  | |   () public
  | o  2:b1661037fa25 added b
  |/    () public
  o  1:c7586e2a9264 added a
  |   () public
  o  0:8fa14d15e168 added hgignore
      () public