annotate tests/test-convert-git.t @ 24545:9e0c67e84896

json: implement {tags} template

Tags is pretty easy to implement. Let's start there.

The output is slightly different from `hg tags -Tjson`. For reference,
the CLI has the following output:

  [
   {
    "node": "e2049974f9a23176c2addb61d8f5b86e0d620490",
    "rev": 29880,
    "tag": "tip",
    "type": ""
   },
   ...
  ]

Our output has the format:

  {
    "node": "0aeb19ea57a6d223bacddda3871cb78f24b06510",
    "tags": [
      {
        "node": "e2049974f9a23176c2addb61d8f5b86e0d620490",
        "tag": "tag1",
        "date": [1427775457.0, 25200]
      },
      ...
    ]
  }

"rev" is omitted because it isn't a reliable identifier. We shouldn't
be exposing them in web APIs and giving the impression it remotely
resembles a stable identifier. Perhaps we could one day hide this behind
a config option (it might be useful to expose when running servers
locally).

The "type" of the tag isn't defined because this information isn't yet
exposed to the hgweb templater (it could be in a follow-up) and because
it is questionable whether different types should be exposed at all.
(Should the web interface really be exposing "local" tags?)

We use an object for the outer type instead of Array for a few reasons.
First, it is extensible. If we ever need to throw more global properties
into the output, we can do that without breaking backwards compatibility
(property additions should be backwards compatible). Second, uniformity
in web APIs is nice. Having everything return objects seems much saner than
a mix of array and object. Third, there are security issues with arrays
in older browsers. The JSON web services world almost never uses arrays
as the main type for this reason.

Another possibly controversial part about this patch is how dates are
defined. While JSON has a Date type, it is based on the JavaScript Date
type, which is widely considered a pile of garbage. It is a non-starter
for this reason.

Many of Mercurial's built-in date filters drop seconds resolution. So
that's a non-starter as well, since we want the API to be lossless where
possible. rfc3339date, rfc822date, isodatesec, and date are all lossless.
However, they each require the client to perform string parsing on top of
JSON decoding. While date parsing libraries are pretty ubiquitous, some
languages don't have them out of the box. However, pretty much every
programming language can deal with UNIX timestamps (which are just
integers or floats). So, we choose to use Mercurial's internal date
representation, which in JSON is modeled as float seconds since UNIX
epoch and an integer timezone offset from UTC (keep in mind
JavaScript/JSON models all "Numbers" as double prevision floating point
numbers, so there isn't a difference between ints and floats in JSON).

#require git

  $ echo "[core]" >> $HOME/.gitconfig
  $ echo "autocrlf = false" >> $HOME/.gitconfig
  $ echo "[core]" >> $HOME/.gitconfig
  $ echo "autocrlf = false" >> $HOME/.gitconfig
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert=" >> $HGRCPATH
  $ GIT_AUTHOR_NAME='test'; export GIT_AUTHOR_NAME
  $ GIT_AUTHOR_EMAIL='[e-mail]'; export GIT_AUTHOR_EMAIL
  $ GIT_AUTHOR_DATE="2007-01-01 00:00:00 +0000"; export GIT_AUTHOR_DATE
  $ GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; export GIT_COMMITTER_NAME
  $ GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"; export GIT_COMMITTER_EMAIL
  $ GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"; export GIT_COMMITTER_DATE
  $ INVALIDID1=afd12345af
  $ INVALIDID2=28173x36ddd1e67bf7098d541130558ef5534a86
  $ VALIDID1=39b3d83f9a69a9ba4ebb111461071a0af0027357
  $ VALIDID2=8dd6476bd09d9c7776355dc454dafe38efaec5da
  $ count=10
  $ commit()
  > {
  >     GIT_AUTHOR_DATE="2007-01-01 00:00:$count +0000"
  >     GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"
  >     git commit "$@" >/dev/null 2>/dev/null || echo "git commit error"
  >     count=`expr $count + 1`
  > }
  $ mkdir git-repo
  $ cd git-repo
  $ git init-db >/dev/null 2>/dev/null
  $ echo a > a
  $ mkdir d
  $ echo b > d/b
  $ git add a d
  $ commit -a -m t1

Remove the directory, then try to replace it with a file (issue754)

  $ git rm -f d/b
  rm 'd/b'
  $ commit -m t2
  $ echo d > d
  $ git add d
  $ commit -m t3
  $ echo b >> a
  $ commit -a -m t4.1
  $ git checkout -b other HEAD~ >/dev/null 2>/dev/null
  $ echo c > a
  $ echo a >> a
  $ commit -a -m t4.2
  $ git checkout master >/dev/null 2>/dev/null
  $ git pull --no-commit . other > /dev/null 2>/dev/null
  $ commit -m 'Merge branch other'
  $ cd ..
  $ hg convert --config extensions.progress= --config progress.assume-tty=1 \
  >   --config progress.delay=0 --config progress.changedelay=0 \
  >   --config progress.refresh=0 --config progress.width=60 \
  > --datesort git-repo
  \r (no-eol) (esc)
  scanning [======>                                     ] 1/6\r (no-eol) (esc)
  scanning [=============>                              ] 2/6\r (no-eol) (esc)
  scanning [=====================>                      ] 3/6\r (no-eol) (esc)
  scanning [============================>               ] 4/6\r (no-eol) (esc)
  scanning [===================================>        ] 5/6\r (no-eol) (esc)
  scanning [===========================================>] 6/6\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [                                          ] 0/6\r (no-eol) (esc)
  getting files [==================>                    ] 1/2\r (no-eol) (esc)
  getting files [======================================>] 2/2\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [======>                                   ] 1/6\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [=============>                            ] 2/6\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [====================>                     ] 3/6\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [===========================>              ] 4/6\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [==================================>       ] 5/6\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  assuming destination git-repo-hg
  initializing destination git-repo-hg repository
  scanning source...
  sorting...
  converting...
  5 t1
  4 t2
  3 t3
  2 t4.1
  1 t4.2
  0 Merge branch other
  updating bookmarks
  $ hg up -q -R git-repo-hg
  $ hg -R git-repo-hg tip -v
  changeset:   5:c78094926be2
  bookmark:    master
  tag:         tip
  parent:      3:f5f5cb45432b
  parent:      4:4e174f80c67c
  user:        test <[e-mail]>
  date:        Mon Jan 01 00:00:15 2007 +0000
  files:       a
  description:
  Merge branch other
  
  
  $ count=10
  $ mkdir git-repo2
  $ cd git-repo2
  $ git init-db >/dev/null 2>/dev/null
  $ echo foo > foo
  $ git add foo
  $ commit -a -m 'add foo'
  $ echo >> foo
  $ commit -a -m 'change foo'
  $ git checkout -b Bar HEAD~ >/dev/null 2>/dev/null
  $ echo quux >> quux
  $ git add quux
  $ commit -a -m 'add quux'
  $ echo bar > bar
  $ git add bar
  $ commit -a -m 'add bar'
  $ git checkout -b Baz HEAD~ >/dev/null 2>/dev/null
  $ echo baz > baz
  $ git add baz
  $ commit -a -m 'add baz'
  $ git checkout master >/dev/null 2>/dev/null
  $ git pull --no-commit . Bar Baz > /dev/null 2>/dev/null
  $ commit -m 'Octopus merge'
  $ echo bar >> bar
  $ commit -a -m 'change bar'
  $ git checkout -b Foo HEAD~ >/dev/null 2>/dev/null
  $ echo >> foo
  $ commit -a -m 'change foo'
  $ git checkout master >/dev/null 2>/dev/null
  $ git pull --no-commit -s ours . Foo > /dev/null 2>/dev/null
  $ commit -m 'Discard change to foo'
  $ cd ..
  $ glog()
  > {
  >     hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
  > }
  $ splitrepo()
  > {
  >     msg="$1"
  >     files="$2"
  >     opts=$3
  >     echo "% $files: $msg"
  >     prefix=`echo "$files" | sed -e 's/ /-/g'`
  >     fmap="$prefix.fmap"
  >     repo="$prefix.repo"
  >     for i in $files; do
  >         echo "include $i" >> "$fmap"
  >     done
  >     hg -q convert $opts --filemap "$fmap" --datesort git-repo2 "$repo"
  >     hg up -q -R "$repo"
  >     glog -R "$repo"
  >     hg -R "$repo" manifest --debug
  > }

full conversion

  $ hg convert --datesort git-repo2 fullrepo \
  > --config extensions.progress= --config progress.assume-tty=1 \
  > --config progress.delay=0 --config progress.changedelay=0 \
  > --config progress.refresh=0 --config progress.width=60
  \r (no-eol) (esc)
  scanning [===>                                        ] 1/9\r (no-eol) (esc)
  scanning [========>                                   ] 2/9\r (no-eol) (esc)
  scanning [=============>                              ] 3/9\r (no-eol) (esc)
  scanning [==================>                         ] 4/9\r (no-eol) (esc)
  scanning [=======================>                    ] 5/9\r (no-eol) (esc)
  scanning [============================>               ] 6/9\r (no-eol) (esc)
  scanning [=================================>          ] 7/9\r (no-eol) (esc)
  scanning [======================================>     ] 8/9\r (no-eol) (esc)
  scanning [===========================================>] 9/9\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [                                          ] 0/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [===>                                      ] 1/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [========>                                 ] 2/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [=============>                            ] 3/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [=================>                        ] 4/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [======================>                   ] 5/9\r (no-eol) (esc)
  getting files [===>                                   ] 1/8\r (no-eol) (esc)
  getting files [========>                              ] 2/8\r (no-eol) (esc)
  getting files [=============>                         ] 3/8\r (no-eol) (esc)
  getting files [==================>                    ] 4/8\r (no-eol) (esc)
  getting files [=======================>               ] 5/8\r (no-eol) (esc)
  getting files [============================>          ] 6/8\r (no-eol) (esc)
  getting files [=================================>     ] 7/8\r (no-eol) (esc)
  getting files [======================================>] 8/8\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [===========================>              ] 6/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [===============================>          ] 7/9\r (no-eol) (esc)
  getting files [======================================>] 1/1\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  \r (no-eol) (esc)
  converting [====================================>     ] 8/9\r (no-eol) (esc)
  getting files [==================>                    ] 1/2\r (no-eol) (esc)
  getting files [======================================>] 2/2\r (no-eol) (esc)
                                                              \r (no-eol) (esc)
  initializing destination fullrepo repository
  scanning source...
  sorting...
  converting...
  8 add foo
  7 change foo
  6 add quux
  5 add bar
  4 add baz
  3 Octopus merge
  2 change bar
  1 change foo
  0 Discard change to foo
  updating bookmarks
  $ hg up -q -R fullrepo
  $ glog -R fullrepo
  @    9 "Discard change to foo" files: foo
  |\
  | o  8 "change foo" files: foo
  | |
  o |  7 "change bar" files: bar
  |/
  o    6 "(octopus merge fixup)" files:
  |\
  | o    5 "Octopus merge" files: baz
  | |\
  o | |  4 "add baz" files: baz
  | | |
  +---o  3 "add bar" files: bar
  | |
  o |  2 "add quux" files: quux
  | |
  | o  1 "change foo" files: foo
  |/
  o  0 "add foo" files: foo
  
  $ hg -R fullrepo manifest --debug
  245a3b8bc653999c2b22cdabd517ccb47aecafdf 644   bar
  354ae8da6e890359ef49ade27b68bbc361f3ca88 644   baz
  9277c9cc8dd4576fc01a17939b4351e5ada93466 644   foo
  88dfeab657e8cf2cef3dec67b914f49791ae76b1 644   quux
  $ splitrepo 'octopus merge' 'foo bar baz'
  % foo bar baz: octopus merge
  @    8 "Discard change to foo" files: foo
  |\
  | o  7 "change foo" files: foo
  | |
  o |  6 "change bar" files: bar
  |/
  o    5 "(octopus merge fixup)" files:
  |\
  | o    4 "Octopus merge" files: baz
  | |\
  o | |  3 "add baz" files: baz
  | | |
  +---o  2 "add bar" files: bar
  | |
  | o  1 "change foo" files: foo
  |/
  o  0 "add foo" files: foo
  
  245a3b8bc653999c2b22cdabd517ccb47aecafdf 644   bar
  354ae8da6e890359ef49ade27b68bbc361f3ca88 644   baz
  9277c9cc8dd4576fc01a17939b4351e5ada93466 644   foo
  $ splitrepo 'only some parents of an octopus merge; "discard" a head' 'foo baz quux'
  % foo baz quux: only some parents of an octopus merge; "discard" a head
  @  6 "Discard change to foo" files: foo
  |
  o  5 "change foo" files: foo
  |
  o    4 "Octopus merge" files:
  |\
  | o  3 "add baz" files: baz
  | |
  | o  2 "add quux" files: quux
  | |
  o |  1 "change foo" files: foo
  |/
  o  0 "add foo" files: foo
  
  354ae8da6e890359ef49ade27b68bbc361f3ca88 644   baz
  9277c9cc8dd4576fc01a17939b4351e5ada93466 644   foo
  88dfeab657e8cf2cef3dec67b914f49791ae76b1 644   quux

test importing git renames and copies

  $ cd git-repo2
  $ git mv foo foo-renamed
since bar is not touched in this commit, this copy will not be detected
  $ cp bar bar-copied
  $ cp baz baz-copied
  $ cp baz baz-copied2
  $ echo baz2 >> baz
  $ git add bar-copied baz-copied baz-copied2
  $ commit -a -m 'rename and copy'
  $ cd ..

input validation
  $ hg convert --config convert.git.similarity=foo --datesort git-repo2 fullrepo
  abort: convert.git.similarity is not an integer ('foo')
  [255]
  $ hg convert --config convert.git.similarity=-1 --datesort git-repo2 fullrepo
  abort: similarity must be between 0 and 100
  [255]
  $ hg convert --config convert.git.similarity=101 --datesort git-repo2 fullrepo
  abort: similarity must be between 0 and 100
  [255]

  $ hg -q convert --config convert.git.similarity=100 --datesort git-repo2 fullrepo
  $ hg -R fullrepo status -C --change master
  M baz
  A bar-copied
  A baz-copied
    baz
  A baz-copied2
    baz
  A foo-renamed
    foo
  R foo

  $ cd git-repo2
  $ echo bar2 >> bar
  $ commit -a -m 'change bar'
  $ cp bar bar-copied2
  $ git add bar-copied2
  $ commit -a -m 'copy with no changes'
  $ cd ..

  $ hg -q convert --config convert.git.similarity=100 \
  > --config convert.git.findcopiesharder=1 --datesort git-repo2 fullrepo
  $ hg -R fullrepo status -C --change master
  A bar-copied2
    bar

test binary conversion (issue1359)

  $ count=19
  $ mkdir git-repo3
  $ cd git-repo3
  $ git init-db >/dev/null 2>/dev/null
  $ $PYTHON -c 'file("b", "wb").write("".join([chr(i) for i in range(256)])*16)'
  $ git add b
  $ commit -a -m addbinary
  $ cd ..

convert binary file

  $ hg convert git-repo3 git-repo3-hg
  initializing destination git-repo3-hg repository
  scanning source...
  sorting...
  converting...
  0 addbinary
  updating bookmarks
  $ cd git-repo3-hg
  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ $PYTHON -c 'print len(file("b", "rb").read())'
  4096
  $ cd ..

test author vs committer

  $ mkdir git-repo4
  $ cd git-repo4
  $ git init-db >/dev/null 2>/dev/null
  $ echo >> foo
  $ git add foo
  $ commit -a -m addfoo
  $ echo >> foo
  $ GIT_AUTHOR_NAME="nottest"
  $ commit -a -m addfoo2
  $ cd ..

convert author committer

  $ hg convert git-repo4 git-repo4-hg
  initializing destination git-repo4-hg repository
  scanning source...
  sorting...
  converting...
  1 addfoo
  0 addfoo2
  updating bookmarks
  $ hg -R git-repo4-hg log -v
  changeset:   1:d63e967f93da
  bookmark:    master
  tag:         tip
  user:        nottest <[e-mail]>
  date:        Mon Jan 01 00:00:21 2007 +0000
  files:       foo
  description:
  addfoo2
  
  committer: test <[e-mail]>
  
  
  changeset:   0:0735477b0224
  user:        test <[e-mail]>
  date:        Mon Jan 01 00:00:20 2007 +0000
  files:       foo
  description:
  addfoo
  
  

--sourceorder should fail

  $ hg convert --sourcesort git-repo4 git-repo4-sourcesort-hg
  initializing destination git-repo4-sourcesort-hg repository
  abort: --sourcesort is not supported by this data source
  [255]

test sub modules

  $ mkdir git-repo5
  $ cd git-repo5
  $ git init-db >/dev/null 2>/dev/null
  $ echo 'sub' >> foo
  $ git add foo
  $ commit -a -m 'addfoo'
  $ BASE=`pwd`
  $ cd ..
  $ mkdir git-repo6
  $ cd git-repo6
  $ git init-db >/dev/null 2>/dev/null
  $ git submodule add ${BASE} >/dev/null 2>/dev/null
  $ commit -a -m 'addsubmodule' >/dev/null 2>/dev/null
  $ cd ..

test invalid splicemap1

  $ cat > splicemap <<EOF
  > $VALIDID1
  > EOF
  $ hg convert --splicemap splicemap git-repo2 git-repo2-splicemap1-hg
  initializing destination git-repo2-splicemap1-hg repository
  abort: syntax error in splicemap(1): child parent1[,parent2] expected
  [255]

test invalid splicemap2

  $ cat > splicemap <<EOF
  > $VALIDID1 $VALIDID2, $VALIDID2, $VALIDID2
  > EOF
  $ hg convert --splicemap splicemap git-repo2 git-repo2-splicemap2-hg
  initializing destination git-repo2-splicemap2-hg repository
  abort: syntax error in splicemap(1): child parent1[,parent2] expected
  [255]

test invalid splicemap3

  $ cat > splicemap <<EOF
  > $INVALIDID1 $INVALIDID2
  > EOF
  $ hg convert --splicemap splicemap git-repo2 git-repo2-splicemap3-hg
  initializing destination git-repo2-splicemap3-hg repository
  abort: splicemap entry afd12345af is not a valid revision identifier
  [255]

convert sub modules
  $ hg convert git-repo6 git-repo6-hg
  initializing destination git-repo6-hg repository
  scanning source...
  sorting...
  converting...
  0 addsubmodule
  updating bookmarks
  $ hg -R git-repo6-hg log -v
  changeset:   0:* (glob)
  bookmark:    master
  tag:         tip
  user:        nottest <[e-mail]>
  date:        Mon Jan 01 00:00:23 2007 +0000
  files:       .hgsub .hgsubstate
  description:
  addsubmodule
  
  committer: test <[e-mail]>
  
  

  $ cd git-repo6-hg
  $ hg up >/dev/null 2>/dev/null
  $ cat .hgsubstate
  * git-repo5 (glob)
  $ cd git-repo5
  $ cat foo
  sub

  $ cd ../..

make sure rename detection doesn't break removing and adding gitmodules

  $ cd git-repo6
  $ git mv .gitmodules .gitmodules-renamed
  $ commit -a -m 'rename .gitmodules'
  $ git mv .gitmodules-renamed .gitmodules
  $ commit -a -m 'rename .gitmodules back'
  $ cd ..

  $ hg --config convert.git.similarity=100 convert -q git-repo6 git-repo6-hg
  $ hg -R git-repo6-hg log -r 'tip^' -T "{desc|firstline}\n"
  rename .gitmodules
  $ hg -R git-repo6-hg status -C --change 'tip^'
  A .gitmodules-renamed
  R .hgsub
  R .hgsubstate
  $ hg -R git-repo6-hg log -r tip -T "{desc|firstline}\n"
  rename .gitmodules back
  $ hg -R git-repo6-hg status -C --change tip
  A .hgsub
  A .hgsubstate
  R .gitmodules-renamed

convert the revision removing '.gitmodules' itself (and related
submodules)

  $ cd git-repo6
  $ git rm .gitmodules
  rm '.gitmodules'
  $ git rm --cached git-repo5
  rm 'git-repo5'
  $ commit -a -m 'remove .gitmodules and submodule git-repo5'
  $ cd ..

  $ hg convert -q git-repo6 git-repo6-hg
  $ hg -R git-repo6-hg tip -T "{desc|firstline}\n"
  remove .gitmodules and submodule git-repo5
  $ hg -R git-repo6-hg tip -T "{file_dels}\n"
  .hgsub .hgsubstate

damaged git repository tests:
In case the hard-coded hashes change, the following commands can be used to
list the hashes and their corresponding types in the repository:
cd git-repo4/.git/objects
find . -type f | cut -c 3- | sed 's_/__' | xargs -n 1 -t git cat-file -t
cd ../../..

damage git repository by renaming a commit object
  $ COMMIT_OBJ=1c/0ce3c5886f83a1d78a7b517cdff5cf9ca17bdd
  $ mv git-repo4/.git/objects/$COMMIT_OBJ git-repo4/.git/objects/$COMMIT_OBJ.tmp
  $ hg convert git-repo4 git-repo4-broken-hg 2>&1 | grep 'abort:'
  abort: cannot read tags from git-repo4/.git
  $ mv git-repo4/.git/objects/$COMMIT_OBJ.tmp git-repo4/.git/objects/$COMMIT_OBJ
damage git repository by renaming a blob object

  $ BLOB_OBJ=8b/137891791fe96927ad78e64b0aad7bded08bdc
  $ mv git-repo4/.git/objects/$BLOB_OBJ git-repo4/.git/objects/$BLOB_OBJ.tmp
  $ hg convert git-repo4 git-repo4-broken-hg 2>&1 | grep 'abort:'
  abort: cannot read 'blob' object at 8b137891791fe96927ad78e64b0aad7bded08bdc
  $ mv git-repo4/.git/objects/$BLOB_OBJ.tmp git-repo4/.git/objects/$BLOB_OBJ
damage git repository by renaming a tree object

  $ TREE_OBJ=72/49f083d2a63a41cc737764a86981eb5f3e4635
  $ mv git-repo4/.git/objects/$TREE_OBJ git-repo4/.git/objects/$TREE_OBJ.tmp
  $ hg convert git-repo4 git-repo4-broken-hg 2>&1 | grep 'abort:'
  abort: cannot read changes in 1c0ce3c5886f83a1d78a7b517cdff5cf9ca17bdd