Mercurial > hg
view tests/test-commit.t @ 40326:fed697fa1734
sqlitestore: file storage backend using SQLite
This commit provides an extension which uses SQLite to store file
data (as opposed to revlogs).
As the inline documentation describes, there are still several
aspects to the extension that are incomplete. But it's a start.
The extension does support basic clone, checkout, and commit
workflows, which makes it suitable for simple use cases.
One notable missing feature is support for "bundlerepos." This is
probably responsible for the most test failures when the extension
is activated as part of the test suite.
All revision data is stored in SQLite. Data is stored as zstd
compressed chunks (default if zstd is available), zlib compressed
chunks (default if zstd is not available), or raw chunks (if
configured or if a compressed delta is not smaller than the raw
delta). This makes things very similar to revlogs.
Unlike revlogs, the extension doesn't yet enforce a limit on delta
chain length. This is an obvious limitation and should be addressed.
This is somewhat mitigated by the use of zstd, which is much faster
than zlib to decompress.
There is a dedicated table for storing deltas. Deltas are stored
by the SHA-1 hash of their uncompressed content. The "fileindex" table
has columns that reference the delta for each revision and the base
delta that delta should be applied against. A recursive SQL query
is used to resolve the delta chain along with the delta data.
By storing deltas by hash, we are able to de-duplicate delta storage!
With revlogs, the same deltas in different revlogs would result in
duplicate storage of that delta. In this scheme, inserting the
duplicate delta is a no-op and delta chains simply reference the
existing delta.
When initially implementing this extension, I did not have
content-indexed deltas and deltas could be duplicated across files
(just like revlogs). When I implemented content-indexed deltas, the
size of the SQLite database for a full clone of mozilla-unified
dropped:
before: 2,554,261,504 bytes
after: 2,488,754,176 bytes
Surprisingly, this is still larger than the bytes size of revlog
files:
revlog files: 2,104,861,230 bytes
du -b: 2,254,381,614
I would have expected storage to be smaller since we're not limiting
delta chain length and since we're using zstd instead of zlib. I
suspect the SQLite indexes and per-column overhead account for the
bulk of the differences. (Keep in mind that revlog uses a 64-byte
packed struct for revision index data and deltas are stored without
padding. Aside from the 12 unused bytes in the 32 byte node field,
revlogs are pretty efficient.) Another source of overhead is file
name storage. With revlogs, file names are stored in the filesystem.
But with SQLite, we need to store file names in the database. This is
roughly equivalent to the size of the fncache file, which for the
mozilla-unified repository is ~34MB.
Since the SQLite database isn't append-only and since delta chains
can reference any delta, this opens some interesting possibilities.
For example, we could store deltas in reverse, such that fulltexts
are stored for newer revisions and deltas are applied to reconstruct
older revisions. This is likely a more optimal storage strategy for
version control, as new data tends to be more frequently accessed
than old data. We would obviously need wire protocol support for
transferring revision data from newest to oldest. And we would
probably need some kind of mechanism for "re-encoding" stores. But
it should be doable.
This extension is very much experimental quality. There are a handful
of features that don't work. It probably isn't suitable for day-to-day
use. But it could be used in limited cases (e.g. read-only checkouts
like in CI). And it is also a good proving ground for alternate
storage backends. As we continue to define interfaces for all things
storage, it will be useful to have a viable alternate storage backend
to see how things shake out in practice.
test-storage.py passes on Python 2 and introduces no new test failures on
Python 3. Having the storage-level unit tests has proved to be insanely
useful when developing this extension. Those tests caught numerous bugs
during development and I'm convinced this style of testing is the way
forward for ensuring alternate storage backends work as intended. Of
course, test coverage isn't close to what it needs to be. But it is
a start. And what coverage we have gives me confidence that basic store
functionality is implemented properly.
Differential Revision: https://phab.mercurial-scm.org/D4928
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 09 Oct 2018 08:50:13 -0700 |
parents | 1a184b727aff |
children | 251332dbf33d |
line wrap: on
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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.changelog.tip(), 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 ..