tests/test-copy-move-merge.t

rust: Use `&HgPath` instead of `&HgPathBuf` in may APIs

Getting the former (through `Deref`) is almost the only useful thing one can
do with the latter anyway. With this changes, API become more flexible for the
"provider" of these paths which may store something else that Deref’s to HgPath,
such as `std::borrow::Cow<HgPath>`. Using `Cow` can help reduce memory alloactions
and copying.

Differential Revision: https://phab.mercurial-scm.org/D10558

Test for the full copytracing algorithm
=======================================


Initial Setup
=============

use git diff to see rename

  $ cat << EOF >> $HGRCPATH
  > [diff]
  > git=yes
  > EOF

Setup an history where one side copy and rename a file (and update it) while the other side update it.

  $ hg init t
  $ cd t

  $ echo 1 > a
  $ hg ci -qAm "first"

  $ hg cp a b
  $ hg mv a c
  $ echo 2 >> b
  $ echo 2 >> c

  $ hg ci -qAm "second"

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

  $ echo 0 > a
  $ echo 1 >> a

  $ hg ci -qAm "other"

  $ hg log -G --patch
  @  changeset:   2:add3f11052fa
  |  tag:         tip
  |  parent:      0:b8bf91eeebbc
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     other
  |
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -1,1 +1,2 @@
  |  +0
  |   1
  |
  | o  changeset:   1:17c05bb7fcb6
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     second
  |
  |    diff --git a/a b/b
  |    rename from a
  |    rename to b
  |    --- a/a
  |    +++ b/b
  |    @@ -1,1 +1,2 @@
  |     1
  |    +2
  |    diff --git a/a b/c
  |    copy from a
  |    copy to c
  |    --- a/a
  |    +++ b/c
  |    @@ -1,1 +1,2 @@
  |     1
  |    +2
  |
  o  changeset:   0:b8bf91eeebbc
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     first
  
     diff --git a/a b/a
     new file mode 100644
     --- /dev/null
     +++ b/a
     @@ -0,0 +1,1 @@
     +1
  

Test Simple Merge
=================

  $ hg merge --debug
    unmatched files in other:
     b
     c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' *
      src: 'a' -> dst: 'c' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: b8bf91eeebbc, local: add3f11052fa+, remote: 17c05bb7fcb6
  starting 4 threads for background file closing (?)
   preserving a for resolve of b
   preserving a for resolve of c
  removing a
   b: remote moved from a -> m (premerge)
  picked tool ':merge' for b (binary False symlink False changedelete False)
  merging a and b to b
  my b@add3f11052fa+ other b@17c05bb7fcb6 ancestor a@b8bf91eeebbc
   premerge successful
   c: remote moved from a -> m (premerge)
  picked tool ':merge' for c (binary False symlink False changedelete False)
  merging a and c to c
  my c@add3f11052fa+ other c@17c05bb7fcb6 ancestor a@b8bf91eeebbc
   premerge successful
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

file b
  $ cat b
  0
  1
  2

file c
  $ cat c
  0
  1
  2

Test disabling copy tracing
===========================

first verify copy metadata was kept
-----------------------------------

  $ hg up -qC 2
  $ hg rebase --keep -d 1 -b 2 --config extensions.rebase=
  rebasing 2:add3f11052fa tip "other"
  merging b and a to b
  merging c and a to c

  $ cat b
  0
  1
  2

 next verify copy metadata is lost when disabled
------------------------------------------------

  $ hg strip -r . --config extensions.strip=
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/t/.hg/strip-backup/550bd84c0cd3-fc575957-backup.hg
  $ hg up -qC 2
  $ hg rebase --keep -d 1 -b 2 --config extensions.rebase= --config experimental.copytrace=off --config ui.interactive=True << EOF
  > c
  > EOF
  rebasing 2:add3f11052fa tip "other"
  file 'a' was deleted in local [dest] but was modified in other [source].
  You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.
  What do you want to do? c

  $ cat b
  1
  2

  $ cd ..

Verify disabling copy tracing still keeps copies from rebase source
-------------------------------------------------------------------

  $ hg init copydisable
  $ cd copydisable
  $ touch a
  $ hg ci -Aqm 'add a'
  $ touch b
  $ hg ci -Aqm 'add b, c'
  $ hg cp b x
  $ echo x >> x
  $ hg ci -qm 'copy b->x'
  $ hg up -q 1
  $ touch z
  $ hg ci -Aqm 'add z'
  $ hg log -G -T '{rev} {desc}\n'
  @  3 add z
  |
  | o  2 copy b->x
  |/
  o  1 add b, c
  |
  o  0 add a
  
  $ hg rebase -d . -b 2 --config extensions.rebase= --config experimental.copytrace=off
  rebasing 2:6adcf8c12e7d "copy b->x"
  saved backup bundle to $TESTTMP/copydisable/.hg/strip-backup/6adcf8c12e7d-ce4b3e75-rebase.hg
  $ hg up -q 3
  $ hg log -f x -T '{rev} {desc}\n'
  3 copy b->x
  1 add b, c

  $ cd ../


test storage preservation
-------------------------

Verify rebase do not discard recorded copies data when copy tracing usage is
disabled.

Setup

  $ hg init copydisable3
  $ cd copydisable3
  $ touch a
  $ hg ci -Aqm 'add a'
  $ hg cp a b
  $ hg ci -Aqm 'copy a->b'
  $ hg mv b c
  $ hg ci -Aqm 'move b->c'
  $ hg up -q 0
  $ hg cp a b
  $ echo b >> b
  $ hg ci -Aqm 'copy a->b (2)'
  $ hg log -G -T '{rev} {desc}\n'
  @  3 copy a->b (2)
  |
  | o  2 move b->c
  | |
  | o  1 copy a->b
  |/
  o  0 add a
  

Actual Test

A file is copied on one side and has been moved twice on the other side. the
file is copied from `0:a`, so the file history of the `3:b` should trace directly to `0:a`.

  $ hg rebase -d 2 -s 3 --config extensions.rebase= --config experimental.copytrace=off
  rebasing 3:47e1a9e6273b tip "copy a->b (2)"
  saved backup bundle to $TESTTMP/copydisable3/.hg/strip-backup/47e1a9e6273b-2d099c59-rebase.hg

  $ hg log -G -f b
  @  changeset:   3:76024fb4b05b
  :  tag:         tip
  :  user:        test
  :  date:        Thu Jan 01 00:00:00 1970 +0000
  :  summary:     copy a->b (2)
  :
  o  changeset:   0:ac82d8b1f7c4
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     add a