view tests/test-copy-move-merge.t @ 44985:1ca0047fd7e1

absorb: preserve changesets which were already empty

Most commands in Mercurial (commit, rebase, absorb itself) don’t create empty
changesets or drop them if they become empty. If there’s a changeset that’s
empty, it must be a deliberate choice of the user. At least it shouldn’t be
absorb’s responsibility to prune them. The fact that changesets that became
empty during absorb are pruned, is unaffected by this.

This case was found while writing patches which make it possible to configure
absorb and rebase to not drop empty changesets. Even without having such config
set, I think it’s valuable to preserve changesets which were already empty.

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
   preserving a for resolve of b
   preserving a for resolve of c
  removing a
  starting 4 threads for background file closing (?)
   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 "other" (tip)
  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 "other" (tip)
  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 "copy a->b (2)" (tip)
  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