view tests/test-rename-merge2.t @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

  $ 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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@e300d1c794ec+ other rev@4ce40f5aca24 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@f4db7e329e71 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@e300d1c794ec+ other rev@bdb19105162a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@f4db7e329e71 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@94b33a1b7f2d+ other rev@4ce40f5aca24 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@97c705ade336 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@94b33a1b7f2d+ other rev@bdb19105162a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@97c705ade336 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
   rev: versions differ -> m (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
   b: both renamed from a -> m (merge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  my b@62e7bf090eba+ other b@49b6d8032493 ancestor a@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  my rev@62e7bf090eba+ other rev@49b6d8032493 ancestor rev@924404dff337
  launching merge tool: * ../merge *$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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@fe905ef2c33e ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  my b@86a2aa42fc76+ other b@af30c7647fc7 ancestor b@000000000000
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  my rev@86a2aa42fc76+ other rev@af30c7647fc7 ancestor rev@924404dff337
  launching merge tool: * ../merge *$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 (premerge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  merging b
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
   rev: versions differ -> m (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
   b: both created -> m (merge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  my b@59318016310c+ other b@bdb19105162a ancestor b@000000000000
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  my rev@59318016310c+ other rev@bdb19105162a ancestor rev@924404dff337
  launching merge tool: * ../merge *$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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@86a2aa42fc76+ other rev@8dbce441892a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@0b76e65c8289+ other rev@4ce40f5aca24 ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@8dbce441892a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@0b76e65c8289+ other rev@bdb19105162a ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 (premerge)
  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
   rev: versions differ -> m (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
   b: remote moved from a -> m (merge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  my b@e300d1c794ec+ other b@49b6d8032493 ancestor a@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  my rev@e300d1c794ec+ other rev@49b6d8032493 ancestor rev@924404dff337
  launching merge tool: * ../merge *$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 (premerge)
  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
   rev: versions differ -> m (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
   b: local copied/moved from a -> m (merge)
  picked tool '* ../merge' for b (binary False symlink False changedelete False) (glob)
  my b@62e7bf090eba+ other a@f4db7e329e71 ancestor a@924404dff337
  launching merge tool: * ../merge *$TESTTMP/t/t/b* * * (glob)
  merge tool returned: 0
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  my rev@62e7bf090eba+ other rev@f4db7e329e71 ancestor rev@924404dff337
  launching merge tool: * ../merge *$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 (premerge)
  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 (premerge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  merging rev
  my rev@02963e448370+ other rev@2b958612230f ancestor rev@924404dff337
   rev: versions differ -> m (merge)
  picked tool '* ../merge' for rev (binary False symlink False changedelete False) (glob)
  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 ..