view tests/test-commit.t @ 39788:ae531f5e583c

testing: add interface unit tests for file storage

Our strategy for supporting alternate storage backends is to define
interfaces for everything then "code to the interface."

We already have interfaces for various primitives, including file
and manifest storage.

What we don't have is generic unit tests for those interfaces. Up
to this point we've been relying on high-level integration tests
(mainly in the form of existing .t tests) to test alternate storage
backends. And my experience with developing the "simple store" test
extension is that such testing is very tedious: it takes several
minutes to run all tests and when you find a failure, it is often
non-trivial to debug.

This commit starts to change that.

This commit introduces the mercurial.testing.storage module. It
contains testing code for storage. Currently, it defines some
unittest.TestCase classes for testing the file storage interfaces.
It also defines some factory functions that allow a caller to easily
spawn a custom TestCase "bound" to a specific file storage backend
implementation.

A new .py test has been added. It simply defines a callable to produce
filelog and transaction instances on demand and then "registers" the
various test classes so the filelog class can be tested with the
storage interface unit tests.

As part of writing the tests, I identified a couple of apparent
bugs in revlog.py and filelog.py! These are tracked with inline
TODO comments.

Writing the tests makes it more obvious where the storage interface
is lacking. For example, we raise either IndexError or
error.LookupError for missing revisions depending on whether we
use an integer revision or a node. Also, we raise error.RevlogError
in various places when we should be raising a storage-agnostic
error type.

The storage interfaces are currently far from perfect and there is much
work to be done to improve them. But at least with this commit we
finally have the start of unit tests that can be used to "qualify"
the behavior of a storage backend. And when implementing and debugging
new storage backends, we now have an obvious place to define new
tests and have obvious places to insert breakpoints to facilitate
debugging. This should be invaluable when implementing new storage
backends.

I added the mercurial.testing package because these interface
conformance tests are generic and need to be usable by all storage
backends. Having the code live in tests/ would make it difficult for
storage backends implemented in extensions to test their interface
conformance. First, it would require obtaining a copy of Mercurial's
storage test code in order to test. Second, it would make testing
against multiple Mercurial versions difficult, as you would need to
import N copies of the storage testing code in order to achieve test
coverage. By making the test code part of the Mercurial distribution
itself, extensions can `import mercurial.testing.*` to access and run
the test code. The test will run against whatever Mercurial version
is active.

FWIW I've always wanted to move parts of run-tests.py into the
mercurial.* package to make the testing story simpler (e.g. imagine an
`hg debugruntests` command that could invoke the test harness). While I
have no plans to do that in the near future, establishing the
mercurial.testing package does provide a natural home for that code
should someone do this in the future.

Differential Revision: https://phab.mercurial-scm.org/D4650

commit date test

  $ hg init test
  $ cd test
  $ echo foo > foo
  $ hg add foo
  $ cat > $TESTTMP/checkeditform.sh <<EOF
  > env | grep HGEDITFORM
  > true
  > EOF
  $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg commit -m ""
  HGEDITFORM=commit.normal.normal
  abort: empty commit message
  [255]
  $ hg commit -d '0 0' -m commit-1
  $ echo foo >> foo
  $ hg commit -d '1 4444444' -m commit-3
  hg: parse error: impossible time zone offset: 4444444
  [255]
  $ hg commit -d '1	15.1' -m commit-4
  hg: parse error: invalid date: '1\t15.1'
  [255]
  $ hg commit -d 'foo bar' -m commit-5
  hg: parse error: invalid date: 'foo bar'
  [255]
  $ hg commit -d ' 1 4444' -m commit-6
  $ hg commit -d '111111111111 0' -m commit-7
  hg: parse error: date exceeds 32 bits: 111111111111
  [255]
  $ hg commit -d '-111111111111 0' -m commit-7
  hg: parse error: date exceeds 32 bits: -111111111111
  [255]
  $ echo foo >> foo
  $ hg commit -d '1901-12-13 20:45:52 +0000' -m commit-7-2
  $ echo foo >> foo
  $ hg commit -d '-2147483648 0' -m commit-7-3
  $ hg log -T '{rev} {date|isodatesec}\n' -l2
  3 1901-12-13 20:45:52 +0000
  2 1901-12-13 20:45:52 +0000
  $ hg commit -d '1901-12-13 20:45:51 +0000' -m commit-7
  hg: parse error: date exceeds 32 bits: -2147483649
  [255]
  $ hg commit -d '-2147483649 0' -m commit-7
  hg: parse error: date exceeds 32 bits: -2147483649
  [255]

commit added file that has been deleted

  $ echo bar > bar
  $ hg add bar
  $ rm bar
  $ hg commit -m commit-8
  nothing changed (1 missing files, see 'hg status')
  [1]
  $ hg commit -m commit-8-2 bar
  abort: bar: file not found!
  [255]

  $ hg -q revert -a --no-backup

  $ mkdir dir
  $ echo boo > dir/file
  $ hg add
  adding dir/file
  $ hg -v commit -m commit-9 dir
  committing files:
  dir/file
  committing manifest
  committing changelog
  committed changeset 4:1957363f1ced

  $ echo > dir.file
  $ hg add
  adding dir.file
  $ hg commit -m commit-10 dir dir.file
  abort: dir: no match under directory!
  [255]

  $ echo >> dir/file
  $ mkdir bleh
  $ mkdir dir2
  $ cd bleh
  $ hg commit -m commit-11 .
  abort: bleh: no match under directory!
  [255]
  $ hg commit -m commit-12 ../dir ../dir2
  abort: dir2: no match under directory!
  [255]
  $ hg -v commit -m commit-13 ../dir
  committing files:
  dir/file
  committing manifest
  committing changelog
  committed changeset 5:a31d8f87544a
  $ cd ..

  $ hg commit -m commit-14 does-not-exist
  abort: does-not-exist: * (glob)
  [255]

#if symlink
  $ ln -s foo baz
  $ hg commit -m commit-15 baz
  abort: baz: file not tracked!
  [255]
  $ rm baz
#endif

  $ touch quux
  $ hg commit -m commit-16 quux
  abort: quux: file not tracked!
  [255]
  $ echo >> dir/file
  $ hg -v commit -m commit-17 dir/file
  committing files:
  dir/file
  committing manifest
  committing changelog
  committed changeset 6:32d054c9d085

An empty date was interpreted as epoch origin

  $ echo foo >> foo
  $ hg commit -d '' -m commit-no-date --config devel.default-date=
  $ hg tip --template '{date|isodate}\n' | grep '1970'
  [1]

Using the advanced --extra flag

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "commitextras=" >> $HGRCPATH
  $ hg status
  ? quux
  $ hg add quux
  $ hg commit -m "adding internal used extras" --extra amend_source=hash
  abort: key 'amend_source' is used internally, can't be set manually
  [255]
  $ hg commit -m "special chars in extra" --extra id@phab=214
  abort: keys can only contain ascii letters, digits, '_' and '-'
  [255]
  $ hg commit -m "empty key" --extra =value
  abort: unable to parse '=value', keys can't be empty
  [255]
  $ hg commit -m "adding extras" --extra sourcehash=foo --extra oldhash=bar
  $ hg log -r . -T '{extras % "{extra}\n"}'
  branch=default
  oldhash=bar
  sourcehash=foo

Failed commit with --addremove should not update dirstate

  $ echo foo > newfile
  $ hg status
  ? newfile
  $ HGEDITOR=false hg ci --addremove
  adding newfile
  abort: edit failed: false exited with status 1
  [255]
  $ hg status
  ? newfile

Make sure we do not obscure unknown requires file entries (issue2649)

  $ echo foo >> foo
  $ echo fake >> .hg/requires
  $ hg commit -m bla
  abort: repository requires features unknown to this Mercurial: fake!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]

  $ cd ..


partial subdir commit test

  $ hg init test2
  $ cd test2
  $ mkdir foo
  $ echo foo > foo/foo
  $ mkdir bar
  $ echo bar > bar/bar
  $ hg add
  adding bar/bar
  adding foo/foo
  $ HGEDITOR=cat hg ci -e -m commit-subdir-1 foo
  commit-subdir-1
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added foo/foo


  $ hg ci -m commit-subdir-2 bar

subdir log 1

  $ hg log -v foo
  changeset:   0:f97e73a25882
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       foo/foo
  description:
  commit-subdir-1
  
  

subdir log 2

  $ hg log -v bar
  changeset:   1:aa809156d50d
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bar/bar
  description:
  commit-subdir-2
  
  

full log

  $ hg log -v
  changeset:   1:aa809156d50d
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bar/bar
  description:
  commit-subdir-2
  
  
  changeset:   0:f97e73a25882
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       foo/foo
  description:
  commit-subdir-1
  
  
  $ cd ..


dot and subdir commit test

  $ hg init test3
  $ echo commit-foo-subdir > commit-log-test
  $ cd test3
  $ mkdir foo
  $ echo foo content > foo/plain-file
  $ hg add foo/plain-file
  $ HGEDITOR=cat hg ci --edit -l ../commit-log-test foo
  commit-foo-subdir
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added foo/plain-file


  $ echo modified foo content > foo/plain-file
  $ hg ci -m commit-foo-dot .

full log

  $ hg log -v
  changeset:   1:95b38e3a5b2e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       foo/plain-file
  description:
  commit-foo-dot
  
  
  changeset:   0:65d4e9386227
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       foo/plain-file
  description:
  commit-foo-subdir
  
  

subdir log

  $ cd foo
  $ hg log .
  changeset:   1:95b38e3a5b2e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-foo-dot
  
  changeset:   0:65d4e9386227
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit-foo-subdir
  
  $ cd ..
  $ cd ..

Issue1049: Hg permits partial commit of merge without warning

  $ hg init issue1049
  $ cd issue1049
  $ echo a > a
  $ hg ci -Ama
  adding a
  $ echo a >> a
  $ hg ci -mb
  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b >> a
  $ hg ci -mc
  created new head
  $ HGMERGE=true hg merge
  merging a
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

should fail because we are specifying a file name

  $ hg ci -mmerge a
  abort: cannot partially commit a merge (do not specify files or patterns)
  [255]

should fail because we are specifying a pattern

  $ hg ci -mmerge -I a
  abort: cannot partially commit a merge (do not specify files or patterns)
  [255]

should succeed

  $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg ci -mmerge --edit
  HGEDITFORM=commit.normal.merge
  $ cd ..


test commit message content

  $ hg init commitmsg
  $ cd commitmsg
  $ echo changed > changed
  $ echo removed > removed
  $ hg book activebookmark
  $ hg ci -qAm init

  $ hg rm removed
  $ echo changed >> changed
  $ echo added > added
  $ hg add added
  $ HGEDITOR=cat hg ci -A
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: bookmark 'activebookmark'
  HG: added added
  HG: changed changed
  HG: removed removed
  abort: empty commit message
  [255]

test saving last-message.txt

  $ hg init sub
  $ echo a > sub/a
  $ hg -R sub add sub/a
  $ cat > sub/.hg/hgrc <<EOF
  > [hooks]
  > precommit.test-saving-last-message = false
  > EOF

  $ echo 'sub = sub' > .hgsub
  $ hg add .hgsub

  $ cat > $TESTTMP/editor.sh <<EOF
  > echo "==== before editing:"
  > cat \$1
  > echo "===="
  > echo "test saving last-message.txt" >> \$1
  > EOF

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg commit -S -q
  ==== before editing:
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: bookmark 'activebookmark'
  HG: subrepo sub
  HG: added .hgsub
  HG: added added
  HG: changed .hgsubstate
  HG: changed changed
  HG: removed removed
  ====
  abort: precommit.test-saving-last-message hook exited with status 1 (in subrepository "sub")
  [255]
  $ cat .hg/last-message.txt
  
  
  test saving last-message.txt

test that '[committemplate] changeset' definition and commit log
specific template keywords work well

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit.normal = 'HG: this is "commit.normal" template
  >     HG: {extramsg}
  >     {if(activebookmark,
  >    "HG: bookmark '{activebookmark}' is activated\n",
  >    "HG: no bookmark is activated\n")}{subrepos %
  >    "HG: subrepo '{subrepo}' is changed\n"}'
  > 
  > changeset.commit = HG: this is "commit" template
  >     HG: {extramsg}
  >     {if(activebookmark,
  >    "HG: bookmark '{activebookmark}' is activated\n",
  >    "HG: no bookmark is activated\n")}{subrepos %
  >    "HG: subrepo '{subrepo}' is changed\n"}
  > 
  > changeset = HG: this is customized commit template
  >     HG: {extramsg}
  >     {if(activebookmark,
  >    "HG: bookmark '{activebookmark}' is activated\n",
  >    "HG: no bookmark is activated\n")}{subrepos %
  >    "HG: subrepo '{subrepo}' is changed\n"}
  > EOF

  $ hg init sub2
  $ echo a > sub2/a
  $ hg -R sub2 add sub2/a
  $ echo 'sub2 = sub2' >> .hgsub

  $ HGEDITOR=cat hg commit -S -q
  HG: this is "commit.normal" template
  HG: Leave message empty to abort commit.
  HG: bookmark 'activebookmark' is activated
  HG: subrepo 'sub' is changed
  HG: subrepo 'sub2' is changed
  abort: empty commit message
  [255]

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit.normal =
  > # now, "changeset.commit" should be chosen for "hg commit"
  > EOF

  $ hg bookmark --inactive activebookmark
  $ hg forget .hgsub
  $ HGEDITOR=cat hg commit -q
  HG: this is "commit" template
  HG: Leave message empty to abort commit.
  HG: no bookmark is activated
  abort: empty commit message
  [255]

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit =
  > # now, "changeset" should be chosen for "hg commit"
  > EOF

  $ HGEDITOR=cat hg commit -q
  HG: this is customized commit template
  HG: Leave message empty to abort commit.
  HG: no bookmark is activated
  abort: empty commit message
  [255]

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset = {desc}
  >     HG: mods={file_mods}
  >     HG: adds={file_adds}
  >     HG: dels={file_dels}
  >     HG: files={files}
  >     HG:
  >     {splitlines(diff()) % 'HG: {line}\n'
  >    }HG:
  >     HG: mods={file_mods}
  >     HG: adds={file_adds}
  >     HG: dels={file_dels}
  >     HG: files={files}\n
  > EOF
  $ hg status -amr
  M changed
  A added
  R removed
  $ HGEDITOR=cat hg commit -q -e -m "foo bar" changed
  foo bar
  HG: mods=changed
  HG: adds=
  HG: dels=
  HG: files=changed
  HG:
  HG: --- a/changed	Thu Jan 01 00:00:00 1970 +0000
  HG: +++ b/changed	Thu Jan 01 00:00:00 1970 +0000
  HG: @@ -1,1 +1,2 @@
  HG:  changed
  HG: +changed
  HG:
  HG: mods=changed
  HG: adds=
  HG: dels=
  HG: files=changed
  $ hg status -amr
  A added
  R removed
  $ hg parents --template "M {file_mods}\nA {file_adds}\nR {file_dels}\n"
  M changed
  A 
  R 
  $ hg rollback -q

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset = {desc}
  >     HG: mods={file_mods}
  >     HG: adds={file_adds}
  >     HG: dels={file_dels}
  >     HG: files={files}
  >     HG:
  >     {splitlines(diff("changed")) % 'HG: {line}\n'
  >    }HG:
  >     HG: mods={file_mods}
  >     HG: adds={file_adds}
  >     HG: dels={file_dels}
  >     HG: files={files}
  >     HG:
  >     {splitlines(diff("added")) % 'HG: {line}\n'
  >    }HG:
  >     HG: mods={file_mods}
  >     HG: adds={file_adds}
  >     HG: dels={file_dels}
  >     HG: files={files}
  >     HG:
  >     {splitlines(diff("removed")) % 'HG: {line}\n'
  >    }HG:
  >     HG: mods={file_mods}
  >     HG: adds={file_adds}
  >     HG: dels={file_dels}
  >     HG: files={files}\n
  > EOF
  $ HGEDITOR=cat hg commit -q -e -m "foo bar" added removed
  foo bar
  HG: mods=
  HG: adds=added
  HG: dels=removed
  HG: files=added removed
  HG:
  HG:
  HG: mods=
  HG: adds=added
  HG: dels=removed
  HG: files=added removed
  HG:
  HG: --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  HG: +++ b/added	Thu Jan 01 00:00:00 1970 +0000
  HG: @@ -0,0 +1,1 @@
  HG: +added
  HG:
  HG: mods=
  HG: adds=added
  HG: dels=removed
  HG: files=added removed
  HG:
  HG: --- a/removed	Thu Jan 01 00:00:00 1970 +0000
  HG: +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
  HG: @@ -1,1 +0,0 @@
  HG: -removed
  HG:
  HG: mods=
  HG: adds=added
  HG: dels=removed
  HG: files=added removed
  $ hg status -amr
  M changed
  $ hg parents --template "M {file_mods}\nA {file_adds}\nR {file_dels}\n"
  M 
  A added
  R removed
  $ hg rollback -q

  $ cat >> .hg/hgrc <<EOF
  > # disable customizing for subsequent tests
  > [committemplate]
  > changeset =
  > EOF

  $ cd ..


commit copy

  $ hg init dir2
  $ cd dir2
  $ echo bleh > bar
  $ hg add bar
  $ hg ci -m 'add bar'

  $ hg cp bar foo
  $ echo >> bar
  $ hg ci -m 'cp bar foo; change bar'

  $ hg debugrename foo
  foo renamed from bar:26d3ca0dfd18e44d796b564e38dd173c9668d3a9
  $ hg debugindex bar
     rev linkrev nodeid       p1           p2
       0       0 26d3ca0dfd18 000000000000 000000000000
       1       1 d267bddd54f7 26d3ca0dfd18 000000000000

Test making empty commits
  $ hg commit --config ui.allowemptycommit=True -m "empty commit"
  $ hg log -r . -v --stat
  changeset:   2:d809f3644287
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  description:
  empty commit
  
  
  
verify pathauditor blocks evil filepaths
  $ cat > evil-commit.py <<EOF
  > from __future__ import absolute_import
  > from mercurial import context, hg, node, ui as uimod
  > notrc = u".h\u200cg".encode('utf-8') + b'/hgrc'
  > u = uimod.ui.load()
  > r = hg.repository(u, b'.')
  > def filectxfn(repo, memctx, path):
  >     return context.memfilectx(repo, memctx, path,
  >         b'[hooks]\nupdate = echo owned')
  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
  >                    b'evil', [notrc], filectxfn, 0)
  > r.commitctx(c)
  > EOF
  $ "$PYTHON" evil-commit.py
#if windows
  $ hg co --clean tip
  abort: path contains illegal component: .h\xe2\x80\x8cg\\hgrc (esc)
  [255]
#else
  $ hg co --clean tip
  abort: path contains illegal component: .h\xe2\x80\x8cg/hgrc (esc)
  [255]
#endif

  $ hg rollback -f
  repository tip rolled back to revision 2 (undo commit)
  $ cat > evil-commit.py <<EOF
  > from __future__ import absolute_import
  > from mercurial import context, hg, node, ui as uimod
  > notrc = b"HG~1/hgrc"
  > u = uimod.ui.load()
  > r = hg.repository(u, b'.')
  > def filectxfn(repo, memctx, path):
  >     return context.memfilectx(repo, memctx, path,
  >         b'[hooks]\nupdate = echo owned')
  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
  >                    b'evil', [notrc], filectxfn, 0)
  > r.commitctx(c)
  > EOF
  $ "$PYTHON" evil-commit.py
  $ hg co --clean tip
  abort: path contains illegal component: HG~1/hgrc
  [255]

  $ hg rollback -f
  repository tip rolled back to revision 2 (undo commit)
  $ cat > evil-commit.py <<EOF
  > from __future__ import absolute_import
  > from mercurial import context, hg, node, ui as uimod
  > notrc = b"HG8B6C~2/hgrc"
  > u = uimod.ui.load()
  > r = hg.repository(u, b'.')
  > def filectxfn(repo, memctx, path):
  >     return context.memfilectx(repo, memctx, path,
  >         b'[hooks]\nupdate = echo owned')
  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
  >                    b'evil', [notrc], filectxfn, 0)
  > r.commitctx(c)
  > EOF
  $ "$PYTHON" evil-commit.py
  $ hg co --clean tip
  abort: path contains illegal component: HG8B6C~2/hgrc
  [255]

# test that an unmodified commit template message aborts

  $ hg init unmodified_commit_template
  $ cd unmodified_commit_template
  $ echo foo > foo
  $ hg add foo
  $ hg commit -m "foo"
  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit = HI THIS IS NOT STRIPPED
  >     HG: this is customized commit template
  >     HG: {extramsg}
  >     {if(activebookmark,
  >    "HG: bookmark '{activebookmark}' is activated\n",
  >    "HG: no bookmark is activated\n")}{subrepos %
  >    "HG: subrepo '{subrepo}' is changed\n"}
  > EOF
  $ cat > $TESTTMP/notouching.sh <<EOF
  > true
  > EOF
  $ echo foo2 > foo2
  $ hg add foo2
  $ HGEDITOR="sh $TESTTMP/notouching.sh" hg commit
  abort: commit message unchanged
  [255]

test that text below the --- >8 --- special string is ignored

  $ cat <<'EOF' > $TESTTMP/lowercaseline.sh
  > cat $1 | sed s/LINE/line/ | tee $1.new
  > mv $1.new $1
  > EOF

  $ hg init ignore_below_special_string
  $ cd ignore_below_special_string
  $ echo foo > foo
  $ hg add foo
  $ hg commit -m "foo"
  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit = first LINE
  >     HG: this is customized commit template
  >     HG: {extramsg}
  >     HG: ------------------------ >8 ------------------------
  >     {diff()}
  > EOF
  $ echo foo2 > foo2
  $ hg add foo2
  $ HGEDITOR="sh $TESTTMP/notouching.sh" hg ci
  abort: commit message unchanged
  [255]
  $ HGEDITOR="sh $TESTTMP/lowercaseline.sh" hg ci
  first line
  HG: this is customized commit template
  HG: Leave message empty to abort commit.
  HG: ------------------------ >8 ------------------------
  diff -r e63c23eaa88a foo2
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo2	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +foo2
  $ hg log -T '{desc}\n' -r .
  first line

test that the special string --- >8 --- isn't used when not at the beginning of
a line

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit = first LINE2
  >     another line HG: ------------------------ >8 ------------------------
  >     HG: this is customized commit template
  >     HG: {extramsg}
  >     HG: ------------------------ >8 ------------------------
  >     {diff()}
  > EOF
  $ echo foo >> foo
  $ HGEDITOR="sh $TESTTMP/lowercaseline.sh" hg ci
  first line2
  another line HG: ------------------------ >8 ------------------------
  HG: this is customized commit template
  HG: Leave message empty to abort commit.
  HG: ------------------------ >8 ------------------------
  diff -r 3661b22b0702 foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,2 @@
   foo
  +foo
  $ hg log -T '{desc}\n' -r .
  first line2
  another line HG: ------------------------ >8 ------------------------

also test that this special string isn't accepted when there is some extra text
at the end

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > changeset.commit = first LINE3
  >     HG: ------------------------ >8 ------------------------foobar
  >     second line
  >     HG: this is customized commit template
  >     HG: {extramsg}
  >     HG: ------------------------ >8 ------------------------
  >     {diff()}
  > EOF
  $ echo foo >> foo
  $ HGEDITOR="sh $TESTTMP/lowercaseline.sh" hg ci
  first line3
  HG: ------------------------ >8 ------------------------foobar
  second line
  HG: this is customized commit template
  HG: Leave message empty to abort commit.
  HG: ------------------------ >8 ------------------------
  diff -r ce648f5f066f foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   foo
   foo
  +foo
  $ hg log -T '{desc}\n' -r .
  first line3
  second line

  $ cd ..