tests/test-mq-merge.t

scmutil: move construction of instability count message to separate fn

When the commad we are running, introduces new instabilities, we show a message
like `5 new orphan changesets`, `2 new content-divergent changesets`, `1 new
phase-divergent changesets` etc which is very nice.

Now taking a step ahead, we want users to show how to fix them too. Something
like:

`5 new orphan changesets (run 'hg evolve' to resolve/stabilize them)`
`2 new content-divergent changesets (run 'hg evolve --content-divergent' to
resolve them)`

and maybe telling user a way to understand more about those new instabilities
like `hg evolve --list` or `hg log -r 'orphan()'` something like that.

The idea came from issue5855 which I want to fix because fixing that will result
in a nice UI.

Taking the construction logic out will allow extensions like evolve (maybe
rebase too) to wrap that and add information about how to resolve and how to
understand the instability more.

Differential Revision: https://phab.mercurial-scm.org/D3734

Setup extension:

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > mq =
  > [mq]
  > git = keep
  > EOF

Test merge with mq changeset as the second parent:

  $ hg init m
  $ cd m
  $ touch a b c
  $ hg add a
  $ hg commit -m a
  $ hg add b
  $ hg qnew -d "0 0" b
  $ hg update 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg add c
  $ hg commit -m c
  created new head
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg commit -m merge
  abort: cannot commit over an applied mq patch
  [255]
  $ cd ..

Issue529: mq aborts when merging patch deleting files

  $ checkundo()
  > {
  >     if [ -f .hg/store/undo ]; then
  >         echo ".hg/store/undo still exists"
  >     fi
  > }

Commit two dummy files in "init" changeset:

  $ hg init t
  $ cd t
  $ echo a > a
  $ echo b > b
  $ hg ci -Am init
  adding a
  adding b
  $ hg tag -l init

Create a patch removing a:

  $ hg qnew rm_a
  $ hg rm a
  $ hg qrefresh -m "rm a"

Save the patch queue so we can merge it later:

  $ hg qsave -c -e
  copy $TESTTMP/t/.hg/patches to $TESTTMP/t/.hg/patches.1
  $ checkundo

Update b and commit in an "update" changeset:

  $ hg up -C init
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b >> b
  $ hg st
  M b
  $ hg ci -m update
  created new head

# Here, qpush used to abort with :
# The system cannot find the file specified => a
  $ hg manifest
  a
  b

  $ hg qpush -a -m
  merging with queue at: $TESTTMP/t/.hg/patches.1
  applying rm_a
  now at: rm_a

  $ checkundo
  $ hg manifest
  b

Ensure status is correct after merge:

  $ hg qpop -a
  popping rm_a
  popping .hg.patches.merge.marker
  patch queue now empty

  $ cd ..

Classic MQ merge sequence *with an explicit named queue*:

  $ hg init t2
  $ cd t2
  $ echo '[diff]' > .hg/hgrc
  $ echo 'nodates = 1' >> .hg/hgrc
  $ echo a > a
  $ hg ci -Am init
  adding a
  $ echo b > a
  $ hg ci -m changea
  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg cp a aa
  $ echo c >> a
  $ hg qnew --git -f -e patcha
  $ echo d >> a
  $ hg qnew -d '0 0' -f -e patcha2

Create the reference queue:

  $ hg qsave -c -e -n refqueue
  copy $TESTTMP/t2/.hg/patches to $TESTTMP/t2/.hg/refqueue
  $ hg up -C 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

Merge:

  $ HGMERGE=internal:other hg qpush -a -m -n refqueue
  merging with queue at: $TESTTMP/t2/.hg/refqueue
  applying patcha
  patching file a
  Hunk #1 succeeded at 2 with fuzz 1 (offset 0 lines).
  fuzz found when applying patch, stopping
  patch didn't work out, merging patcha
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  applying patcha2
  now at: patcha2

Check patcha is still a git patch:

  $ cat .hg/patches/patcha
  # HG changeset patch
  # Parent  d3873e73d99ef67873dac33fbcc66268d5d2b6f4
  
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
  -b
  +a
  +c
  diff --git a/a b/aa
  copy from a
  copy to aa
  --- a/a
  +++ b/aa
  @@ -1,1 +1,1 @@
  -b
  +a

Check patcha2 is still a regular patch:

  $ cat .hg/patches/patcha2
  # HG changeset patch
  # Date 0 0
  # Parent  ???????????????????????????????????????? (glob)
  
  diff -r ???????????? -r ???????????? a (glob)
  --- a/a
  +++ b/a
  @@ -1,2 +1,3 @@
   a
   c
  +d

  $ cd ..