annotate tests/test-rename-merge2.t @ 32151:4d504e541d3d

rebase: use matcher to optimize manifestmerge

The old merge code would call manifestmerge and calculate the complete diff
between the source to the destination. In many cases, like rebase, the vast
majority of differences between the source and destination are irrelevant
because they are differences between the destination and the common ancestor
only, and therefore don't affect the merge. Since most actions are 'keep', all
the effort to compute them is wasted.

Instead, let's compute the difference between the source and the common ancestor
and only perform the diff of those files against the merge destination. When
using treemanifest, this lets us avoid loading almost the entire tree when
rebasing from a very old ancestor. This speeds up rebase of an old stack of 27
commits by 20x.

In mozilla-central, without treemanifest, when rebasing a commit from
default~100000 to default, this speeds up the manifestmerge step from 2.6s to
1.2s.  However, the additional diff adds an overhead to all manifestmerge calls,
especially for flat manifests. When rebasing a commit from default~1 to default
it appears to add 100ms in mozilla-central. While we could put this optimization
behind a flag, I think the fact that it makes merge O(number of changes being
applied) instead of O(number of changes between X and Y) justifies it.

  $ mkdir -p t
  $ cd t
  $ cat <<EOF > merge
  > import sys, os
  > f = open(sys.argv[1], "wb")
  > 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
  > }
  $ uc() { up $1; hg cp $1 $2; } # update + copy
  $ 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
  --------------
    searching for copies back to rev 1
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: e300d1c794ec+, remote: 4ce40f5aca24
   preserving a for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   b: remote copied from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging a and b to b
  my b@e300d1c794ec+ other b@4ce40f5aca24 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@e300d1c794ec+ other rev@4ce40f5aca24 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@e300d1c794ec+ other rev@4ce40f5aca24 ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: f4db7e329e71
   preserving b for resolve of b
   preserving rev for resolve of rev
   a: remote is newer -> g
  getting a
   b: local copied/moved from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b and a to b
  my b@86a2aa42fc76+ other a@f4db7e329e71 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@86a2aa42fc76+ other rev@f4db7e329e71 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@86a2aa42fc76+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: e300d1c794ec+, remote: bdb19105162a
   preserving a for resolve of b
   preserving rev for resolve of rev
  removing a
  starting 4 threads for background file closing (?)
   b: remote moved from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging a and b to b
  my b@e300d1c794ec+ other b@bdb19105162a ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@e300d1c794ec+ other rev@bdb19105162a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@e300d1c794ec+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: f4db7e329e71
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   b: local copied/moved from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b and a to b
  my b@02963e448370+ other a@f4db7e329e71 ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@02963e448370+ other rev@f4db7e329e71 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@02963e448370+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 94b33a1b7f2d+, remote: 4ce40f5aca24
   preserving rev for resolve of rev
   b: remote created -> g
  getting b
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@94b33a1b7f2d+ other rev@4ce40f5aca24 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@94b33a1b7f2d+ other rev@4ce40f5aca24 ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: 97c705ade336
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@86a2aa42fc76+ other rev@97c705ade336 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@86a2aa42fc76+ other rev@97c705ade336 ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 94b33a1b7f2d+, remote: bdb19105162a
   preserving rev for resolve of rev
   a: other deleted -> r
  removing a
   b: remote created -> g
  getting b
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@94b33a1b7f2d+ other rev@bdb19105162a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@94b33a1b7f2d+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' 
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: 97c705ade336
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@02963e448370+ other rev@97c705ade336 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@02963e448370+ other rev@97c705ade336 ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 62e7bf090eba+, remote: 49b6d8032493
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   b: both renamed from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
   b: both renamed from a -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    unmatched files in other:
     c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' !
     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
   preserving rev for resolve of rev
   c: remote created -> g
  getting c
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@02963e448370+ other rev@fe905ef2c33e ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@02963e448370+ other rev@fe905ef2c33e ancestor rev@924404dff337
  launching merge tool: python ../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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: af30c7647fc7
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 59318016310c+, remote: bdb19105162a
   preserving b for resolve of b
   preserving rev for resolve of rev
   a: other deleted -> r
  removing a
  starting 4 threads for background file closing (?)
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: 8dbce441892a
   preserving b for resolve of b
   preserving rev for resolve of rev
   a: remote is newer -> g
  getting a
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 59318016310c+, remote: bdb19105162a
   preserving b for resolve of b
   preserving rev for resolve of rev
   a: other deleted -> r
  removing a
  starting 4 threads for background file closing (?)
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 86a2aa42fc76+, remote: 8dbce441892a
   preserving b for resolve of b
   preserving rev for resolve of rev
   a: remote is newer -> g
  getting a
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@86a2aa42fc76+ other b@8dbce441892a ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 0b76e65c8289+, remote: 4ce40f5aca24
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@0b76e65c8289+ other b@4ce40f5aca24 ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@0b76e65c8289+ other rev@4ce40f5aca24 ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@0b76e65c8289+ other b@4ce40f5aca24 ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@0b76e65c8289+ other rev@4ce40f5aca24 ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: 8dbce441892a
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   a: prompt deleted/changed -> m (premerge)
  picked tool ':prompt' for a (binary False symlink False changedelete True)
  other [merge rev] changed a which local [working copy] deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? u
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@02963e448370+ other b@8dbce441892a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@02963e448370+ other rev@8dbce441892a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@02963e448370+ other b@8dbce441892a ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@02963e448370+ other rev@8dbce441892a ancestor rev@924404dff337
  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  --------------
  M a
  M b
  abort: unresolved merge conflicts (see 'hg help resolve')
  --------------
  
  $ 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
  --------------
    searching for copies back to rev 1
    unmatched files new in both:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 0b76e65c8289+, remote: bdb19105162a
   preserving a for resolve of a
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   a: prompt changed/deleted -> m (premerge)
  picked tool ':prompt' for a (binary False symlink False changedelete True)
  local [working copy] changed a which other [merge rev] deleted
  use (c)hanged version, (d)elete, or leave (u)nresolved? u
   b: both created -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b
  my b@0b76e65c8289+ other b@bdb19105162a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@0b76e65c8289+ other rev@bdb19105162a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@0b76e65c8289+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@0b76e65c8289+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: python ../merge *$TESTTMP/t/t/rev* * * (glob)
  merge tool returned: 0
  0 files updated, 2 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  --------------
  M b
  C a
  abort: unresolved merge conflicts (see 'hg help resolve')
  --------------
  
  $ 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
  --------------
    searching for copies back to rev 1
    unmatched files in other:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: e300d1c794ec+, remote: 49b6d8032493
   preserving a for resolve of b
   preserving rev for resolve of rev
  removing a
  starting 4 threads for background file closing (?)
   b: remote moved from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging a and b to b
  my b@e300d1c794ec+ other b@49b6d8032493 ancestor a@924404dff337
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
   b: remote moved from a -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@e300d1c794ec+ other b@49b6d8032493 ancestor a@924404dff337
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 62e7bf090eba+, remote: f4db7e329e71
   preserving b for resolve of b
   preserving rev for resolve of rev
  starting 4 threads for background file closing (?)
   b: local copied/moved from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b and a to b
  my b@62e7bf090eba+ other a@f4db7e329e71 ancestor a@924404dff337
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
   b: local copied/moved from a -> m (merge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  my b@62e7bf090eba+ other a@f4db7e329e71 ancestor a@924404dff337
  launching merge tool: python ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: python ../merge *$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
  --------------
    searching for copies back to rev 1
    unmatched files in local:
     b
    unmatched files in other:
     c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 924404dff337, local: 02963e448370+, remote: 2b958612230f
   preserving b for resolve of b
   preserving rev for resolve of rev
   c: remote created -> g
  getting c
   b: local copied/moved from a -> m (premerge)
  picked tool 'python ../merge' for b (binary False symlink False changedelete False)
  merging b and a to b
  my b@02963e448370+ other a@2b958612230f ancestor a@924404dff337
   premerge successful
   rev: versions differ -> m (premerge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  merging rev
  my rev@02963e448370+ other rev@2b958612230f ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool 'python ../merge' for rev (binary False symlink False changedelete False)
  my rev@02963e448370+ other rev@2b958612230f ancestor rev@924404dff337
  launching merge tool: python ../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
    searching for copies back to rev 1
    unmatched files in local:
     5/g
     6/g
    unmatched files in other:
     3/g
     4/g
     7/f
    unmatched files new in both:
     0/f
     1/g
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: '3/f' -> dst: '3/g' *
     src: '4/f' -> dst: '4/g' *
     src: '5/f' -> dst: '5/g' *
     src: '6/f' -> dst: '6/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 ..