view tests/test-evolve-content-divergent-case-A2.t @ 5777:c5dfbbe4363d

evolve: when relocating, optionally first try to do it using in-memory merge

This patch adds a config option to let run evolve's relocation step
using in-memory merge. It is disabled by default. When the option is
on, the relocation is first attempted in memory. If that fails because
of merge conflicts, it retries that commit in the working copy.

There are a few reasons that I made it configurable. The most
important one is that the precommit hook won't trigger when using
in-memory merge. Another reason is that it lets us roll out the
feature slowly to our users at Google.

For now, we also update the working copy after creating the commit (in the
successful case, when there are no merge conflicts). The next patch will make it
so we don't do that update.

Because of the unnecessary working-copy update, this patch doesn't
provide any benefit on its own. Evolving 29 commits that each change
one line in the hg slows down from ~4.5s to ~4.8s when the config
option is on.

I've added `#testcases inmemory ondisk` to select `.t` files. Almost
all differences are because of the new "hit merge conflicts" message
and retrying the merge. There's also one difference in
`test-stabilize-order.t` caused by the different order of working copy
updates (we now update the working copy at the end).

===============================================
Testing content-divergence resolution: Case A.2
===============================================

Independent rewrites of same changeset can lead to content-divergence. In most
common cases, it can occur when multiple users rewrite the same changeset
independently and push it.

This test belongs to a series of tests checking the resolution of content-divergent
changesets.

Category A: no parents are obsolete
Testcase 2: no conflict: both sides amended content changes (non-conflicting changes in same file)

A.2 both sides amended content changes
======================================

.. (Divergence reason):
..    local: amended some content changes in same file as "other" but non-conflicting
..    other: amended some content changes in same file as "local" but non-conflicting
.. Where we show that since both side amended some content changes without any relocation,
.. the most reasonable behaviour is to simply perform 3-way merge.
..
.. (local):
..
..   A ø⇠○ A'
..     |/
..     ● O
..
.. (other):
..
..   A ø⇠○ A''
..     |/
..     ● O
..
.. (Resolution):
..
..     ○ A'''
..     |
..     ● O
..

Setup
-----
  $ . $TESTDIR/testlib/content-divergence-util.sh
  $ setuprepos A.2
  creating test repo for test case A.2
  - upstream
  - local
  - other
  cd into `local` and proceed with env setup

initial

  $ cd local
  $ mkcommit A0
  $ hg push -q
  $ sed -i '1ifoo' A0
  $ hg amend -m "A1"
  $ hg log -G --hidden
  @  2:e1f7c24563ba (draft): A1
  |
  | x  1:28b51eb45704 (draft): A0
  |/
  o  0:a9bdc8b26820 (public): O
  
  $ cd ../other
  $ hg pull -uq
  $ echo bar >> A0
  $ hg amend
  $ hg push -q

  $ cd ../local
  $ hg pull -q
  2 new content-divergent changesets

Actual test of resolution
-------------------------
  $ hg evolve -l
  e1f7c24563ba: A1
    content-divergent: 5fbe90f37421 (draft) (precursor 28b51eb45704)
  
  5fbe90f37421: A0
    content-divergent: e1f7c24563ba (draft) (precursor 28b51eb45704)
  
  $ hg log -G --hidden
  *  3:5fbe90f37421 (draft): A0 [content-divergent]
  |
  | @  2:e1f7c24563ba (draft): A1 [content-divergent]
  |/
  | x  1:28b51eb45704 (draft): A0
  |/
  o  0:a9bdc8b26820 (public): O
  

  $ hg evolve --content-divergent
  merge:[2] A1
  with: [3] A0
  base: [1] A0
  merging A0
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  working directory is now at 414367a5568a

  $ hg log -Gp
  @  4:414367a5568a (draft): A1
  |  diff -r a9bdc8b26820 -r 414367a5568a A0
  |  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  |  +++ b/A0	Thu Jan 01 00:00:00 1970 +0000
  |  @@ -0,0 +1,3 @@
  |  +foo
  |  +A0
  |  +bar
  |
  o  0:a9bdc8b26820 (public): O
     diff -r 000000000000 -r a9bdc8b26820 O
     --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     +++ b/O	Thu Jan 01 00:00:00 1970 +0000
     @@ -0,0 +1,1 @@
     +O
  
  $ hg evolve -l