tests/test-rename-merge2.t

rust: fix unsound `OwningDirstateMap`

As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.

The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.

I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.

In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.

Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.

Differential Revision: https://phab.mercurial-scm.org/D12429

  $ mkdir -p t
  $ cd t
  $ cat <<EOF > merge
  > import sys, os
  > f = open(sys.argv[1], "w")
  > f.write("merge %s %s %s" % (sys.argv[1], sys.argv[2], sys.argv[3]))
  > f.close()
  > EOF

perform a test merge with possible renaming
args:
$1 = action in local branch
$2 = action in remote branch
$3 = action in working dir
$4 = expected result

  $ tm()
  > {
  >     hg init t
  >     cd t
  >     echo "[merge]" >> .hg/hgrc
  >     echo "followcopies = 1" >> .hg/hgrc
  > 
  >     # base
  >     echo base > a
  >     echo base > rev # used to force commits
  >     hg add a rev
  >     hg ci -m "base"
  > 
  >     # remote
  >     echo remote > rev
  >     if [ "$2" != "" ] ; then $2 ; fi
  >     hg ci -m "remote"
  > 
  >     # local
  >     hg co -q 0
  >     echo local > rev
  >     if [ "$1" != "" ] ; then $1 ; fi
  >     hg ci -m "local"
  > 
  >     # working dir
  >     echo local > rev
  >     if [ "$3" != "" ] ; then $3 ; fi
  > 
  >     # merge
  >     echo "--------------"
  >     echo "test L:$1 R:$2 W:$3 - $4"
  >     echo "--------------"
  >     hg merge -y --debug --traceback --tool="\"$PYTHON\" ../merge"
  > 
  >     echo "--------------"
  >     hg status -camC -X rev
  > 
  >     hg ci -m "merge"
  > 
  >     echo "--------------"
  >     echo
  > 
  >     cd ..
  >     rm -r t
  > }
  $ up() {
  >     cp rev $1
  >     hg add $1 2> /dev/null
  >     if [ "$2" != "" ] ; then
  >         cp rev $2
  >         hg add $2 2> /dev/null
  >     fi
  > }
  $ um() { up $1; hg mv $1 $2; }
  $ nc() { hg cp $1 $2; } # just copy
  $ nm() { hg mv $1 $2; } # just move
  $ tm "up a  " "nc a b" "      " "1  get local a to b"
  created new head
  --------------
  test L:up a   R:nc a b W:       - 1  get local a to b
  --------------
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: e300d1c794ec+, remote: 4ce40f5aca24
  starting 4 threads for background file closing (?)
   preserving a for resolve of b
   preserving rev for resolve of rev
   b: remote copied from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging a and b to b
  my b@e300d1c794ec+ other b@4ce40f5aca24 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@e300d1c794ec+ other rev@4ce40f5aca24 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
    a
  C a
  --------------
  
  $ tm "nc a b" "up a  " "      " "2  get rem change to a and b"
  created new head
  --------------
  test L:nc a b R:up a   W:       - 2  get rem change to a and b
  --------------
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: f4db7e329e71
   a: remote is newer -> g
  getting a
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: local copied/moved from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b and a to b
  my b@86a2aa42fc76+ other a@f4db7e329e71 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M a
  M b
    a
  --------------
  
  $ tm "up a  " "nm a b" "      " "3  get local a change to b, remove a"
  created new head
  --------------
  test L:up a   R:nm a b W:       - 3  get local a change to b, remove a
  --------------
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: e300d1c794ec+, remote: bdb19105162a
  starting 4 threads for background file closing (?)
   preserving a for resolve of b
   preserving rev for resolve of rev
  removing a
   b: remote moved from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging a and b to b
  my b@e300d1c794ec+ other b@bdb19105162a ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@e300d1c794ec+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
    a
  --------------
  
  $ tm "nm a b" "up a  " "      " "4  get remote change to b"
  created new head
  --------------
  test L:nm a b R:up a   W:       - 4  get remote change to b
  --------------
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: f4db7e329e71
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: local copied/moved from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b and a to b
  my b@02963e448370+ other a@f4db7e329e71 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
    a
  --------------
  
  $ tm "      " "nc a b" "      " "5  get b"
  created new head
  --------------
  test L:       R:nc a b W:       - 5  get b
  --------------
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 94b33a1b7f2d+, remote: 4ce40f5aca24
   b: remote created -> g
  getting b
   preserving rev for resolve of rev
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@94b33a1b7f2d+ other rev@4ce40f5aca24 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  C a
  --------------
  
  $ tm "nc a b" "      " "      " "6  nothing"
  created new head
  --------------
  test L:nc a b R:       W:       - 6  nothing
  --------------
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: 97c705ade336
  starting 4 threads for background file closing (?)
   preserving rev for resolve of rev
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@97c705ade336 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  C a
  C b
  --------------
  
  $ tm "      " "nm a b" "      " "7  get b"
  created new head
  --------------
  test L:       R:nm a b W:       - 7  get b
  --------------
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 94b33a1b7f2d+, remote: bdb19105162a
   a: other deleted -> r
  removing a
   b: remote created -> g
  getting b
   preserving rev for resolve of rev
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@94b33a1b7f2d+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 1 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  --------------
  
  $ tm "nm a b" "      " "      " "8  nothing"
  created new head
  --------------
  test L:nm a b R:       W:       - 8  nothing
  --------------
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: 97c705ade336
  starting 4 threads for background file closing (?)
   preserving rev for resolve of rev
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@97c705ade336 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  C b
  --------------
  
  $ tm "um a b" "um a b" "      " "9  do merge with ancestor in a"
  created new head
  --------------
  test L:um a b R:um a b W:       - 9  do merge with ancestor in a
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
     on remote side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 62e7bf090eba+, remote: 49b6d8032493
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both renamed from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  --------------
  

m "um a c" "um x c" "      " "10 do merge with no ancestor"

  $ tm "nm a b" "nm a c" "      " "11 get c, keep b"
  created new head
  --------------
  test L:nm a b R:nm a c W:       - 11 get c, keep b
  --------------
    unmatched files in local:
     b
    unmatched files in other:
     c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' !
     on remote side:
      src: 'a' -> dst: 'c' !
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: fe905ef2c33e
  note: possible conflict - a was renamed multiple times to:
   b
   c
   c: remote created -> g
  getting c
   preserving rev for resolve of rev
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@fe905ef2c33e ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M c
  C b
  --------------
  
  $ tm "nc a b" "up b  " "      " "12 merge b no ancestor"
  created new head
  --------------
  test L:nc a b R:up b   W:       - 12 merge b no ancestor
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: af30c7647fc7
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both created -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  C a
  --------------
  
  $ tm "up b  " "nm a b" "      " "13 merge b no ancestor"
  created new head
  --------------
  test L:up b   R:nm a b W:       - 13 merge b no ancestor
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 59318016310c+, remote: bdb19105162a
   a: other deleted -> r
  removing a
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both created -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  --------------
  
  $ tm "nc a b" "up a b" "      " "14 merge b no ancestor"
  created new head
  --------------
  test L:nc a b R:up a b W:       - 14 merge b no ancestor
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: 8dbce441892a
   a: remote is newer -> g
  getting a
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both renamed from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@86a2aa42fc76+ other b@8dbce441892a ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M a
  M b
  --------------
  
  $ tm "up b  " "nm a b" "      " "15 merge b no ancestor, remove a"
  created new head
  --------------
  test L:up b   R:nm a b W:       - 15 merge b no ancestor, remove a
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 59318016310c+, remote: bdb19105162a
   a: other deleted -> r
  removing a
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both created -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  --------------
  
  $ tm "nc a b" "up a b" "      " "16 get a, merge b no ancestor"
  created new head
  --------------
  test L:nc a b R:up a b W:       - 16 get a, merge b no ancestor
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: 8dbce441892a
   a: remote is newer -> g
  getting a
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both renamed from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@86a2aa42fc76+ other b@8dbce441892a ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M a
  M b
  --------------
  
  $ tm "up a b" "nc a b" "      " "17 keep a, merge b no ancestor"
  created new head
  --------------
  test L:up a b R:nc a b W:       - 17 keep a, merge b no ancestor
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 0b76e65c8289+, remote: 4ce40f5aca24
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both renamed from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@0b76e65c8289+ other b@4ce40f5aca24 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@0b76e65c8289+ other rev@4ce40f5aca24 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  C a
  --------------
  
  $ tm "nm a b" "up a b" "      " "18 merge b no ancestor"
  created new head
  --------------
  test L:nm a b R:up a b W:       - 18 merge b no ancestor
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: 8dbce441892a
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both renamed from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@02963e448370+ other b@8dbce441892a ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@8dbce441892a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  --------------
  
  $ tm "up a b" "nm a b" "      " "19 merge b no ancestor, prompt remove a"
  created new head
  --------------
  test L:up a b R:nm a b W:       - 19 merge b no ancestor, prompt remove a
  --------------
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 0b76e65c8289+, remote: bdb19105162a
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: both renamed from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@0b76e65c8289+ other b@bdb19105162a ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@0b76e65c8289+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
  C a
  --------------
  
  $ tm "up a  " "um a b" "      " "20 merge a and b to b, remove a"
  created new head
  --------------
  test L:up a   R:um a b W:       - 20 merge a and b to b, remove a
  --------------
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: e300d1c794ec+, remote: 49b6d8032493
  starting 4 threads for background file closing (?)
   preserving a for resolve of b
   preserving rev for resolve of rev
  removing a
   b: remote moved from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging a and b to b
  my b@e300d1c794ec+ other b@49b6d8032493 ancestor a@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
    a
  --------------
  
  $ tm "um a b" "up a  " "      " "21 merge a and b to b"
  created new head
  --------------
  test L:um a b R:up a   W:       - 21 merge a and b to b
  --------------
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 62e7bf090eba+, remote: f4db7e329e71
  starting 4 threads for background file closing (?)
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: local copied/moved from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b and a to b
  my b@62e7bf090eba+ other a@f4db7e329e71 ancestor a@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
    a
  --------------
  

m "nm a b" "um x a" "      " "22 get a, keep b"

  $ tm "nm a b" "up a c" "      " "23 get c, keep b"
  created new head
  --------------
  test L:nm a b R:up a c W:       - 23 get c, keep b
  --------------
    unmatched files in local:
     b
    unmatched files in other:
     c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: 2b958612230f
   c: remote created -> g
  getting c
   preserving b for resolve of b
   preserving rev for resolve of rev
   b: local copied/moved from a -> m
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b and a to b
  my b@02963e448370+ other a@2b958612230f ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@2b958612230f ancestor rev@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  1 files updated, 2 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  --------------
  M b
    a
  M c
  --------------
  

  $ cd ..


Systematic and terse testing of merge merges and ancestor calculation:

Expected result:

\  a  m1  m2  dst
0  -   f   f   f   "versions differ"
1  f   g   g   g   "versions differ"
2  f   f   f   f   "versions differ"
3  f   f   g  f+g  "remote copied to " + f
4  f   f   g   g   "remote moved to " + f
5  f   g   f  f+g  "local copied to " + f2
6  f   g   f   g   "local moved to " + f2
7  -  (f)  f   f   "remote differs from untracked local"
8  f  (f)  f   f   "remote differs from untracked local"

  $ hg init ancestortest
  $ cd ancestortest
  $ for x in 1 2 3 4 5 6 8; do mkdir $x; echo a > $x/f; done
  $ hg ci -Aqm "a"
  $ mkdir 0
  $ touch 0/f
  $ hg mv 1/f 1/g
  $ hg cp 5/f 5/g
  $ hg mv 6/f 6/g
  $ hg rm 8/f
  $ for x in */*; do echo m1 > $x; done
  $ hg ci -Aqm "m1"
  $ hg up -qr0
  $ mkdir 0 7
  $ touch 0/f 7/f
  $ hg mv 1/f 1/g
  $ hg cp 3/f 3/g
  $ hg mv 4/f 4/g
  $ for x in */*; do echo m2 > $x; done
  $ hg ci -Aqm "m2"
  $ hg up -qr1
  $ mkdir 7 8
  $ echo m > 7/f
  $ echo m > 8/f
  $ hg merge -f --tool internal:dump -v --debug -r2 | sed '/^resolving manifests/,$d' 2> /dev/null
    unmatched files in local:
     5/g
     6/g
    unmatched files in other:
     3/g
     4/g
     7/f
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: '1/f' -> dst: '1/g' *
      src: '5/f' -> dst: '5/g' *
      src: '6/f' -> dst: '6/g' *
     on remote side:
      src: '1/f' -> dst: '1/g' *
      src: '3/f' -> dst: '3/g' *
      src: '4/f' -> dst: '4/g' *
    checking for directory renames
  $ hg mani
  0/f
  1/g
  2/f
  3/f
  4/f
  5/f
  5/g
  6/g
  $ for f in */*; do echo $f:; cat $f; done
  0/f:
  m1
  0/f.base:
  0/f.local:
  m1
  0/f.orig:
  m1
  0/f.other:
  m2
  1/g:
  m1
  1/g.base:
  a
  1/g.local:
  m1
  1/g.orig:
  m1
  1/g.other:
  m2
  2/f:
  m1
  2/f.base:
  a
  2/f.local:
  m1
  2/f.orig:
  m1
  2/f.other:
  m2
  3/f:
  m1
  3/f.base:
  a
  3/f.local:
  m1
  3/f.orig:
  m1
  3/f.other:
  m2
  3/g:
  m1
  3/g.base:
  a
  3/g.local:
  m1
  3/g.orig:
  m1
  3/g.other:
  m2
  4/g:
  m1
  4/g.base:
  a
  4/g.local:
  m1
  4/g.orig:
  m1
  4/g.other:
  m2
  5/f:
  m1
  5/f.base:
  a
  5/f.local:
  m1
  5/f.orig:
  m1
  5/f.other:
  m2
  5/g:
  m1
  5/g.base:
  a
  5/g.local:
  m1
  5/g.orig:
  m1
  5/g.other:
  m2
  6/g:
  m1
  6/g.base:
  a
  6/g.local:
  m1
  6/g.orig:
  m1
  6/g.other:
  m2
  7/f:
  m
  7/f.base:
  7/f.local:
  m
  7/f.orig:
  m
  7/f.other:
  m2
  8/f:
  m2
  $ cd ..