view tests/test-evolve-content-divergent-case-A4.t @ 6935:954d7ea5cd67 stable tip

stack: when stack base is obsolete, pick any successor, even if at random

There are situations when s0 is obsolete and we also cannot pick just one
successor for it to use in stack. In such a case, let's pick the "latest"
successor from the first set.

We're assuming that obsutil.successorssets() returns data in the same order (it
should, since it makes sure to sort data internally). Keeping that in mind,
while the successor picked for s0 by this code is not based on any sort of
sophisticated logic, it should nonetheless be the same every time.

This patch is probably not going to completely break anything that was
previously working fine, because the previous behavior was to just abort with
an exception.

===============================================
Testing content-divergence resolution: Case A.4
===============================================

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 4: both sides relocated forward to different location but aligned
Variants:
# a: local is ahead of other
# b: other is ahead of local

A.4 Both relocated forward
==========================

.. (Divergence reason):
..    local: relocated the changeset forward in the graph but on the same topo branch
..    other: relocated the changeset forward in the graph but on the same topo branch
.. Where we show that since both changesets relocated forward in the graph,
.. we can assume the reason for ahead one being ahead is that it's rebased on the latest changes and
.. its parent should be the resolution parent. So, we will relocate the other changeset to resolution
.. parent and perform 3-way merge.
..
.. (local):
..
..    D ø⇠○ D'
..      | |
..      | ○ C
..      | |
..      | ○ B
..      \ |
..        ○ A
..        |
..        ● O
..
.. (other):
..
..    D ø⇠○ D''
..      | |  ○ C
..      | | /
..      | ○ B
..      \ |
..        ○ A
..        |
..        ● O
..
.. (Resolution):
..     ○ D'''
..     |
..     ○ C
..     |
..     ○ B
..     |
..     ○ A
..     |
..     ● O
..

Setup
-----
  $ . $TESTDIR/testlib/content-divergence-util.sh
  $ setuprepos A.4
  creating test repo for test case A.4
  - upstream
  - local
  - other
  cd into `local` and proceed with env setup

initial

  $ cd upstream
  $ mkcommit A
  $ mkcommit B
  $ mkcommit C
  $ hg co -r 'desc(A)'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkcommit D
  created new head
  $ cd ../local
  $ hg pull -qu
  $ hg rebase -r 'desc(D)' -d 'desc(C)'
  rebasing 4:6a418860e87b tip "D"

  $ cd ../other
  $ hg pull -qu
  $ hg rebase -r 'desc(D)' -d 'desc(B)'
  rebasing 4:6a418860e87b tip "D"
  $ hg push -q

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

Actual test of resolution
-------------------------

Variant_a: when local is ahead of other
---------------------------------------

  $ hg evolve -l
  d203ddccc9cc: D
    content-divergent: 5d3fd66cb347 (draft) (precursor 6a418860e87b)
  
  5d3fd66cb347: D
    content-divergent: d203ddccc9cc (draft) (precursor 6a418860e87b)
  
  $ hg log -G --hidden
  *  6:5d3fd66cb347 (draft): D [content-divergent]
  |
  | @  5:d203ddccc9cc (draft): D [content-divergent]
  | |
  | | x  4:6a418860e87b (draft): D
  | | |
  | o |  3:d90aa47aa5d3 (draft): C
  |/ /
  o /  2:f6fbb35d8ac9 (draft): B
  |/
  o  1:f5bc6836db60 (draft): A
  |
  o  0:a9bdc8b26820 (public): O
  
  $ hg evolve --content-divergent
  merge:[5] D
  with: [6] D
  base: [4] D
  rebasing "other" content-divergent changeset 5d3fd66cb347 on d90aa47aa5d3
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  working directory is now at 898f6bbfb21e

  $ hg log -G
  @  8:898f6bbfb21e (draft): D
  |
  o  3:d90aa47aa5d3 (draft): C
  |
  o  2:f6fbb35d8ac9 (draft): B
  |
  o  1:f5bc6836db60 (draft): A
  |
  o  0:a9bdc8b26820 (public): O
  
  $ hg evolve -l

Variant_b: when other is ahead of local
---------------------------------------

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

  $ hg evolve -l
  5d3fd66cb347: D
    content-divergent: d203ddccc9cc (draft) (precursor 6a418860e87b)
  
  d203ddccc9cc: D
    content-divergent: 5d3fd66cb347 (draft) (precursor 6a418860e87b)
  
  $ hg log -G --hidden
  *  6:d203ddccc9cc (draft): D [content-divergent]
  |
  | @  5:5d3fd66cb347 (draft): D [content-divergent]
  | |
  | | x  4:6a418860e87b (draft): D
  | | |
  o | |  3:d90aa47aa5d3 (draft): C
  |/ /
  o /  2:f6fbb35d8ac9 (draft): B
  |/
  o  1:f5bc6836db60 (draft): A
  |
  o  0:a9bdc8b26820 (public): O
  
  $ hg evolve --content-divergent
  merge:[5] D
  with: [6] D
  base: [4] D
  rebasing "divergent" content-divergent changeset 5d3fd66cb347 on d90aa47aa5d3
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  working directory is now at b2ef9cafa8ac

  $ hg log -G
  @  8:b2ef9cafa8ac (draft): D
  |
  o  3:d90aa47aa5d3 (draft): C
  |
  o  2:f6fbb35d8ac9 (draft): B
  |
  o  1:f5bc6836db60 (draft): A
  |
  o  0:a9bdc8b26820 (public): O