tests/test-merge-internal-tools-pattern.t

phases: track phase changes from 'retractboundary'

We adds new computation to find and record the revision affected by the
boundary retraction. This add more complication to the function but this seems
fine since it is only used in a couple of rare and explicit cases (`hg phase
--force` and `hg qimport`).

Having strong tracking of phase changes is worth the effort.

Make sure that the internal merge tools (internal:fail, internal:local,
internal:union and internal:other) are used when matched by a
merge-pattern in hgrc

Make sure HGMERGE doesn't interfere with the test:

  $ unset HGMERGE

  $ hg init

Initial file contents:

  $ echo "line 1" > f
  $ echo "line 2" >> f
  $ echo "line 3" >> f
  $ hg ci -Am "revision 0"
  adding f

  $ cat f
  line 1
  line 2
  line 3

Branch 1: editing line 1:

  $ sed 's/line 1/first line/' f > f.new
  $ mv f.new f
  $ hg ci -Am "edited first line"

Branch 2: editing line 3:

  $ hg update 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed 's/line 3/third line/' f > f.new
  $ mv f.new f
  $ hg ci -Am "edited third line"
  created new head

Merge using internal:fail tool:

  $ echo "[merge-patterns]" > .hg/hgrc
  $ echo "* = internal:fail" >> .hg/hgrc

  $ hg merge
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ cat f
  line 1
  line 2
  third line

  $ hg stat
  M f

Merge using internal:local tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed 's/internal:fail/internal:local/' .hg/hgrc > .hg/hgrc.new
  $ mv .hg/hgrc.new .hg/hgrc

  $ hg merge
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  line 1
  line 2
  third line

  $ hg stat
  M f

Merge using internal:other tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed 's/internal:local/internal:other/' .hg/hgrc > .hg/hgrc.new
  $ mv .hg/hgrc.new .hg/hgrc

  $ hg merge
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  first line
  line 2
  line 3

  $ hg stat
  M f

Merge using default tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hg/hgrc

  $ hg merge
  merging f
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  first line
  line 2
  third line

  $ hg stat
  M f

Merge using internal:union tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "line 4a" >>f
  $ hg ci -Am "Adding fourth line (commit 4)"
  $ hg update 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "line 4b" >>f
  $ hg ci -Am "Adding fourth line v2 (commit 5)"
  created new head

  $ echo "[merge-patterns]" > .hg/hgrc
  $ echo "* = internal:union" >> .hg/hgrc

  $ hg merge 3
  merging f
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  line 1
  line 2
  third line
  line 4b
  line 4a