view tests/test-grab.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.

Test for the grab command

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

  $ mkcommit() {
  >    echo "$1" > "$1"
  >    hg add "$1"
  >    hg ci -m "add $1"
  > }

  $ hg init repo
  $ cd repo
  $ hg help grab
  hg grab [-r] rev
  
  grabs a commit, move it on the top of working directory parent and
      updates to it.
  
  options:
  
   -r --rev VALUE revision to grab
   -c --continue  continue interrupted grab
   -a --abort     abort interrupted grab
  
  (some details hidden, use --verbose to show complete help)

  $ mkcommit a
  $ mkcommit b
  $ mkcommit c

  $ hg glog
  @  2:4538525df7e2 add c
  |
  o  1:7c3bad9141dc add b
  |
  o  0:1f0dee641bb7 add a
  

Grabbing an ancestor

  $ hg grab -r 7c3bad9141dc
  abort: cannot grab an ancestor revision
  [255]

Grabbing the working directory parent

  $ hg grab -r .
  abort: cannot grab an ancestor revision
  [255]

Specifying multiple revisions to grab

  $ hg grab 1f0dee641bb7 -r 7c3bad9141dc
  abort: specify just one revision
  [255]

Specifying no revisions to grab

  $ hg grab
  abort: empty revision set
  [255]

Continuing without interrupted grab

  $ hg grab --continue
  abort: no interrupted grab state exists
  [255]

Aborting without interrupted grab

  $ hg grab --abort
  abort: no interrupted grab state exists
  [255]

Specifying both continue and revs

  $ hg up 1f0dee641bb7
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg grab -r 4538525df7e2 --continue
  abort: cannot specify both --continue and revision
  [255]

Making new branch heads

  $ mkcommit x
  created new head
  $ mkcommit y

  $ hg glog
  @  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  | o  2:4538525df7e2 add c
  | |
  | o  1:7c3bad9141dc add b
  |/
  o  0:1f0dee641bb7 add a
  
Grabbing a revision

  $ hg grab 7c3bad9141dc
  grabbing 1:7c3bad9141dc "add b"
  1 new orphan changesets
  $ hg glog
  @  5:7c15c05db6fa add b
  |
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  | *  2:4538525df7e2 add c
  | |
  | x  1:7c3bad9141dc add b
  |/
  o  0:1f0dee641bb7 add a
  

When grab does not create any changes

  $ hg graft -r 4538525df7e2
  grafting 2:4538525df7e2 "add c"

  $ hg glog
  @  6:c4636a81ebeb add c
  |
  o  5:7c15c05db6fa add b
  |
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  | *  2:4538525df7e2 add c
  | |
  | x  1:7c3bad9141dc add b
  |/
  o  0:1f0dee641bb7 add a
  
  $ hg grab -r 4538525df7e2
  grabbing 2:4538525df7e2 "add c"
  note: grab of 2:4538525df7e2 created no changes to commit

  $ hg glog
  @  6:c4636a81ebeb add c
  |
  o  5:7c15c05db6fa add b
  |
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  o  0:1f0dee641bb7 add a
  
interrupted grab

  $ hg up d46dc301d92f
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo foo > c
  $ hg ci -Aqm "foo to c"
  $ hg grab -r c4636a81ebeb
  grabbing 6:c4636a81ebeb "add c"
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  unresolved merge conflicts (see hg help resolve)
  [1]

  $ echo foobar > c
  $ hg resolve --all --mark
  (no more unresolved files)
  continue: hg grab --continue
  $ hg grab --continue
  $ hg glog
  @  8:44e155eb95c7 add c
  |
  o  7:2ccc03d1d096 foo to c
  |
  | o  5:7c15c05db6fa add b
  |/
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  o  0:1f0dee641bb7 add a
  

When interrupted grab results in no changes to commit

  $ hg up d46dc301d92f
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo bar > c
  $ hg add c
  $ hg ci -m "foo to c"
  created new head

  $ hg up 44e155eb95c7
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg grab 4e04628911f6
  grabbing 9:4e04628911f6 "foo to c"
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  unresolved merge conflicts (see hg help resolve)
  [1]
  $ echo foobar > c
  $ hg resolve -m
  (no more unresolved files)
  continue: hg grab --continue

  $ hg grab --continue
  note: grab of 9:4e04628911f6 created no changes to commit

Testing the abort functionality of hg grab

  $ echo foo > b
  $ hg ci -Aqm "foo to b"
  $ hg glog -r .^::
  @  10:c437988de89f foo to b
  |
  o  8:44e155eb95c7 add c
  |
  ~

  $ hg grab -r 7c15c05db6fa
  grabbing 5:7c15c05db6fa "add b"
  merging b
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  unresolved merge conflicts (see hg help resolve)
  [1]

  $ hg grab --abort
  aborting grab, updating to c437988de89f

  $ hg glog
  @  10:c437988de89f foo to b
  |
  o  8:44e155eb95c7 add c
  |
  o  7:2ccc03d1d096 foo to c
  |
  | o  5:7c15c05db6fa add b
  |/
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  o  0:1f0dee641bb7 add a
  

Trying to grab a public changeset

  $ hg phase -r 7c15c05db6fa -p

  $ hg grab -r 7c15c05db6fa
  abort: cannot grab public changesets: 7c15c05db6fa
  (see 'hg help phases' for details)
  [255]

  $ hg glog
  @  10:c437988de89f foo to b
  |
  o  8:44e155eb95c7 add c
  |
  o  7:2ccc03d1d096 foo to c
  |
  | o  5:7c15c05db6fa add b
  |/
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  o  0:1f0dee641bb7 add a
  
Checking phase preservation while grabbing secret changeset

In case of merge conflicts

  $ hg phase -r 7c15c05db6fa -s -f

  $ hg grab -r 7c15c05db6fa
  grabbing 5:7c15c05db6fa "add b"
  merging b
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  unresolved merge conflicts (see hg help resolve)
  [1]

  $ echo bar > b
  $ hg resolve -m
  (no more unresolved files)
  continue: hg grab --continue

  $ hg grab --continue
  $ hg phase -r .
  11: secret

No merge conflicts

  $ hg up d46dc301d92f
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ echo foo > l
  $ hg add l
  $ hg ci -qm "added l" --secret

  $ hg phase -r .
  12: secret

  $ hg glog
  @  12:508d572e7053 added l
  |
  | o  11:10427de9e26e add b
  | |
  | o  10:c437988de89f foo to b
  | |
  | o  8:44e155eb95c7 add c
  | |
  | o  7:2ccc03d1d096 foo to c
  |/
  o  4:d46dc301d92f add y
  |
  o  3:8e224524cd09 add x
  |
  o  0:1f0dee641bb7 add a
  
  $ hg up 10427de9e26e
  3 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg grab -r 508d572e7053
  grabbing 12:508d572e7053 "added l"

  $ hg phase -r .
  13: secret