view tests/test-backout.t @ 42044:bb271ec2fbfb

compression: introduce a `storage.revlog.zstd.level` configuration This option control the zstd compression level used when compressing revlog chunk. The usage of zstd for revlog compression has not graduated from experimental yet, but we intend to fix that soon. The option name for the compression level is more straight forward to pick, so this changesets comes first. Having a dedicated option for each compression engine is useful because they don't support the same range of values. I ran the same measurement as for the zlib compression level (in the parent changesets). The variation in repository size is stay mostly in the same (small) range. The "read/write" performance see smallish variation, but are overall much better than zlib. Write performance show the same tend of having better write performance for when reaching high-end compression. Again, we don't intend to change the default zstd compression level (currently: 3) in this series. However this is worth investigating in the future. The Performance comparison of zlib vs zstd is quite impressive. The repository size stay in the same range, but the performance are much better in all situations. Comparison summary ================== We are looking at: - performance range for zlib - performance range for zstd - comparison of default zstd (level-3) to default zlib (level 6) - comparison of the slowest zstd time to the fastest zlib time Read performance: ----------------- | zlib | zstd | cmp | f2s mercurial | 0.170159 - 0.189219 | 0.144127 - 0.149624 | 80% | 88% pypy | 2.679217 - 2.768691 | 1.532317 - 1.705044 | 60% | 63% netbeans | 122.477027 - 141.620281 | 72.996346 - 89.731560 | 58% | 73% mozilla | 147.867662 - 170.572118 | 91.700995 - 105.853099 | 56% | 71% Write performance: ------------------ | zlib | zstd | cmp | f2s mercurial | 53.250304 - 56.2936129 | 40.877025 - 45.677286 | 75% | 86% pypy | 460.721984 - 476.589918 | 270.545409 - 301.002219 | 63% | 65% netbeans | 520.560316 - 715.930400 | 370.356311 - 428.329652 | 55% | 82% mozilla | 739.803002 - 987.056093 | 505.152906 - 591.930683 | 57% | 80% Raw data -------- repo alg lvl .hg/store size 00manifest.d read write mercurial zlib 1 49,402,813 5,963,475 0.170159 53.250304 mercurial zlib 6 47,197,397 5,875,730 0.182820 56.264320 mercurial zlib 9 47,121,596 5,849,781 0.189219 56.293612 mercurial zstd 1 49,737,084 5,966,355 0.144127 40.877025 mercurial zstd 3 48,961,867 5,895,208 0.146376 42.268142 mercurial zstd 5 48,200,592 5,938,676 0.149624 43.162875 mercurial zstd 10 47,833,520 5,913,353 0.145185 44.012489 mercurial zstd 15 47,314,604 5,728,679 0.147686 45.677286 mercurial zstd 20 47,330,502 5,830,539 0.145789 45.025407 mercurial zstd 22 47,330,076 5,830,539 0.143996 44.690460 pypy zlib 1 370,830,572 28,462,425 2.679217 460.721984 pypy zlib 6 340,112,317 27,648,747 2.768691 467.537158 pypy zlib 9 338,360,736 27,639,003 2.763495 476.589918 pypy zstd 1 362,377,479 27,916,214 1.532317 270.545409 pypy zstd 3 354,137,693 27,905,988 1.686718 294.951509 pypy zstd 5 342,640,043 27,655,774 1.705044 301.002219 pypy zstd 10 334,224,327 27,164,493 1.567287 285.186239 pypy zstd 15 329,000,363 26,645,965 1.637729 299.561332 pypy zstd 20 324,534,039 26,199,547 1.526813 302.149827 pypy zstd 22 324,530,595 26,198,932 1.525718 307.821218 netbeans zlib 1 1,281,847,810 165,495,457 122.477027 520.560316 netbeans zlib 6 1,205,284,353 159,161,207 139.876147 715.930400 netbeans zlib 9 1,197,135,671 155,034,586 141.620281 678.297064 netbeans zstd 1 1,259,581,737 160,840,613 72.996346 370.356311 netbeans zstd 3 1,232,978,122 157,691,551 81.622317 396.733087 netbeans zstd 5 1,208,034,075 160,246,880 83.080549 364.342626 netbeans zstd 10 1,188,624,176 156,083,417 79.323935 403.594602 netbeans zstd 15 1,176,973,589 153,859,477 89.731560 428.329652 netbeans zstd 20 1,162,958,258 151,147,535 82.842667 392.335349 netbeans zstd 22 1,162,707,029 151,150,220 82.565695 402.840655 mozilla zlib 1 2,775,497,186 298,527,987 147.867662 751.263721 mozilla zlib 6 2,596,856,420 286,597,671 170.572118 987.056093 mozilla zlib 9 2,587,542,494 287,018,264 163.622338 739.803002 mozilla zstd 1 2,723,159,348 286,617,532 91.700995 570.042751 mozilla zstd 3 2,665,055,001 286,152,013 95.240155 561.412805 mozilla zstd 5 2,607,819,817 288,060,030 101.978048 505.152906 mozilla zstd 10 2,558,761,085 283,967,648 104.113481 497.771202 mozilla zstd 15 2,526,216,060 275,581,300 105.853099 591.930683 mozilla zstd 20 2,485,114,806 266,478,859 95.268795 576.515389 mozilla zstd 22 2,484,869,080 266,456,505 94.429282 572.785537
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Wed, 27 Mar 2019 18:35:59 +0100
parents 7e99b02768ef
children 99ebde4fec99
line wrap: on
line source

  $ hg init basic
  $ cd basic

should complain

  $ hg backout
  abort: please specify a revision to backout
  [255]
  $ hg backout -r 0 0
  abort: please specify just one revision
  [255]

basic operation
(this also tests that editor is invoked if the commit message is not
specified explicitly)

  $ echo a > a
  $ hg commit -d '0 0' -A -m a
  adding a
  $ echo b >> a
  $ hg commit -d '1 0' -m b

  $ hg status --rev tip --rev "tip^1"
  M a
  $ HGEDITOR=cat hg backout -d '2 0' tip --tool=true
  reverting a
  Backed out changeset a820f4f40a57
  
  
  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: changed a
  changeset 2:2929462c3dff backs out changeset 1:a820f4f40a57
  $ cat a
  a
  $ hg summary
  parent: 2:2929462c3dff tip
   Backed out changeset a820f4f40a57
  branch: default
  commit: (clean)
  update: (current)
  phases: 3 draft

commit option

  $ cd ..
  $ hg init commit
  $ cd commit

  $ echo tomatoes > a
  $ hg add a
  $ hg commit -d '0 0' -m tomatoes

  $ echo chair > b
  $ hg add b
  $ hg commit -d '1 0' -m chair

  $ echo grapes >> a
  $ hg commit -d '2 0' -m grapes

  $ hg backout -d '4 0' 1 --tool=:fail
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  changeset 3:1c2161e97c0a backs out changeset 1:22cb4f70d813
  $ hg summary
  parent: 3:1c2161e97c0a tip
   Backed out changeset 22cb4f70d813
  branch: default
  commit: (clean)
  update: (current)
  phases: 4 draft

  $ echo ypples > a
  $ hg commit -d '5 0' -m ypples

  $ hg backout -d '6 0' 2 --tool=:fail
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  [1]
  $ hg summary
  parent: 4:ed99997b793d tip
   ypples
  branch: default
  commit: 1 unresolved (clean)
  update: (current)
  phases: 5 draft

file that was removed is recreated
(this also tests that editor is not invoked if the commit message is
specified explicitly)

  $ cd ..
  $ hg init remove
  $ cd remove

  $ echo content > a
  $ hg commit -d '0 0' -A -m a
  adding a

  $ hg rm a
  $ hg commit -d '1 0' -m b

  $ HGEDITOR=cat hg backout -d '2 0' tip --tool=true -m "Backed out changeset 76862dcce372"
  adding a
  changeset 2:de31bdc76c0d backs out changeset 1:76862dcce372
  $ cat a
  content
  $ hg summary
  parent: 2:de31bdc76c0d tip
   Backed out changeset 76862dcce372
  branch: default
  commit: (clean)
  update: (current)
  phases: 3 draft

backout of backout is as if nothing happened

  $ hg backout -d '3 0' --merge tip --tool=true
  removing a
  changeset 3:7f6d0f120113 backs out changeset 2:de31bdc76c0d
  $ test -f a
  [1]
  $ hg summary
  parent: 3:7f6d0f120113 tip
   Backed out changeset de31bdc76c0d
  branch: default
  commit: (clean)
  update: (current)
  phases: 4 draft

Test that 'hg rollback' restores dirstate just before opening
transaction: in-memory dirstate changes should be written into
'.hg/journal.dirstate' as expected.

  $ echo 'removed soon' > b
  $ hg commit -A -d '4 0' -m 'prepare for subsequent removing'
  adding b
  $ echo 'newly added' > c
  $ hg add c
  $ hg remove b
  $ hg commit -d '5 0' -m 'prepare for subsequent backout'
  $ touch -t 200001010000 c
  $ hg status -A
  C c
  $ hg debugstate --no-dates
  n 644         12 set                 c
  $ hg backout -d '6 0' -m 'to be rollback-ed soon' -r .
  removing c
  adding b
  changeset 6:4bfec048029d backs out changeset 5:fac0b729a654
  $ hg rollback -q
  $ hg status -A
  A b
  R c
  $ hg debugstate --no-dates
  a   0         -1 unset               b
  r   0          0 set                 c

across branch

  $ cd ..
  $ hg init branch
  $ cd branch
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ echo b > b
  $ hg ci -Am1
  adding b
  $ hg co -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg summary
  parent: 0:f7b1eb17ad24 
   0
  branch: default
  commit: (clean)
  update: 1 new changesets (update)
  phases: 2 draft

should fail

  $ hg backout 1
  abort: cannot backout change that is not an ancestor
  [255]
  $ echo c > c
  $ hg ci -Am2
  adding c
  created new head
  $ hg summary
  parent: 2:db815d6d32e6 tip
   2
  branch: default
  commit: (clean)
  update: 1 new changesets, 2 branch heads (merge)
  phases: 3 draft

should fail

  $ hg backout 1
  abort: cannot backout change that is not an ancestor
  [255]
  $ hg summary
  parent: 2:db815d6d32e6 tip
   2
  branch: default
  commit: (clean)
  update: 1 new changesets, 2 branch heads (merge)
  phases: 3 draft

backout with merge

  $ cd ..
  $ hg init merge
  $ cd merge

  $ echo line 1 > a
  $ echo line 2 >> a
  $ hg commit -d '0 0' -A -m a
  adding a
  $ hg summary
  parent: 0:59395513a13a tip
   a
  branch: default
  commit: (clean)
  update: (current)
  phases: 1 draft

remove line 1

  $ echo line 2 > a
  $ hg commit -d '1 0' -m b

  $ echo line 3 >> a
  $ hg commit -d '2 0' -m c

  $ hg backout --merge -d '3 0' 1 --tool=true
  reverting a
  created new head
  changeset 3:26b8ccb9ad91 backs out changeset 1:5a50a024c182
  merging with changeset 3:26b8ccb9ad91
  merging a
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg commit -d '4 0' -m d
  $ hg summary
  parent: 4:c7df5e0b9c09 tip
   d
  branch: default
  commit: (clean)
  update: (current)
  phases: 5 draft

check line 1 is back

  $ cat a
  line 1
  line 2
  line 3

Test visibility of in-memory dirstate changes outside transaction to
external hook process

  $ cat > $TESTTMP/checkvisibility.sh <<EOF
  > echo "==== \$1:"
  > hg parents --template "{rev}:{node|short}\n"
  > echo "===="
  > EOF

"hg backout --merge REV1" at REV2 below implies steps below:

(1) update to REV1 (REV2 => REV1)
(2) revert by REV1^1
(3) commit backing out revision (REV3)
(4) update to REV2 (REV3 => REV2)
(5) merge with REV3 (REV2 => REV2, REV3)

== test visibility to external preupdate hook

  $ hg update -q -C 2
  $ hg --config extensions.strip= strip 3
  saved backup bundle to * (glob)

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > preupdate.visibility = sh $TESTTMP/checkvisibility.sh preupdate
  > EOF

("-m" is needed to avoid writing dirstate changes out at other than
invocation of the hook to be examined)

  $ hg backout --merge -d '3 0' 1 --tool=true -m 'fixed comment'
  ==== preupdate:
  2:6ea3f2a197a2
  ====
  reverting a
  created new head
  changeset 3:d92a3f57f067 backs out changeset 1:5a50a024c182
  ==== preupdate:
  3:d92a3f57f067
  ====
  merging with changeset 3:d92a3f57f067
  ==== preupdate:
  2:6ea3f2a197a2
  ====
  merging a
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > preupdate.visibility =
  > EOF

== test visibility to external update hook

  $ hg update -q -C 2
  $ hg --config extensions.strip= strip 3
  saved backup bundle to * (glob)

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > update.visibility = sh $TESTTMP/checkvisibility.sh update
  > EOF

  $ hg backout --merge -d '3 0' 1 --tool=true -m 'fixed comment'
  ==== update:
  1:5a50a024c182
  ====
  reverting a
  created new head
  changeset 3:d92a3f57f067 backs out changeset 1:5a50a024c182
  ==== update:
  2:6ea3f2a197a2
  ====
  merging with changeset 3:d92a3f57f067
  merging a
  ==== update:
  2:6ea3f2a197a2
  3:d92a3f57f067
  ====
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > update.visibility =
  > EOF

  $ cd ..

backout should not back out subsequent changesets

  $ hg init onecs
  $ cd onecs
  $ echo 1 > a
  $ hg commit -d '0 0' -A -m a
  adding a
  $ echo 2 >> a
  $ hg commit -d '1 0' -m b
  $ echo 1 > b
  $ hg commit -d '2 0' -A -m c
  adding b
  $ hg summary
  parent: 2:882396649954 tip
   c
  branch: default
  commit: (clean)
  update: (current)
  phases: 3 draft

without --merge
  $ hg backout --no-commit -d '3 0' 1 --tool=true
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  changeset 22bca4c721e5 backed out, don't forget to commit.
  $ hg locate b
  b
  $ hg update -C tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg locate b
  b
  $ hg summary
  parent: 2:882396649954 tip
   c
  branch: default
  commit: (clean)
  update: (current)
  phases: 3 draft

with --merge
  $ hg backout --merge -d '3 0' 1 --tool=true
  reverting a
  created new head
  changeset 3:3202beb76721 backs out changeset 1:22bca4c721e5
  merging with changeset 3:3202beb76721
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg locate b
  b
  $ hg update -C tip
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg locate b
  [1]

  $ cd ..
  $ hg init m
  $ cd m
  $ echo a > a
  $ hg commit -d '0 0' -A -m a
  adding a
  $ echo b > b
  $ hg commit -d '1 0' -A -m b
  adding b
  $ echo c > c
  $ hg commit -d '2 0' -A -m b
  adding c
  $ hg update 1
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo d > d
  $ hg commit -d '3 0' -A -m c
  adding d
  created new head
  $ hg merge 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg commit -d '4 0' -A -m d
  $ hg summary
  parent: 4:b2f3bb92043e tip
   d
  branch: default
  commit: (clean)
  update: (current)
  phases: 5 draft

backout of merge should fail

  $ hg backout 4
  abort: cannot backout a merge changeset
  [255]

backout of merge with bad parent should fail

  $ hg backout --parent 0 4
  abort: cb9a9f314b8b is not a parent of b2f3bb92043e
  [255]

backout of non-merge with parent should fail

  $ hg backout --parent 0 3
  abort: cannot use --parent on non-merge changeset
  [255]

backout with valid parent should be ok

  $ hg backout -d '5 0' --parent 2 4 --tool=true
  removing d
  changeset 5:10e5328c8435 backs out changeset 4:b2f3bb92043e
  $ hg summary
  parent: 5:10e5328c8435 tip
   Backed out changeset b2f3bb92043e
  branch: default
  commit: (clean)
  update: (current)
  phases: 6 draft

  $ hg rollback
  repository tip rolled back to revision 4 (undo commit)
  working directory now based on revision 4
  $ hg update -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg summary
  parent: 4:b2f3bb92043e tip
   d
  branch: default
  commit: (clean)
  update: (current)
  phases: 5 draft

  $ hg backout -d '6 0' --parent 3 4 --tool=true
  removing c
  changeset 5:033590168430 backs out changeset 4:b2f3bb92043e
  $ hg summary
  parent: 5:033590168430 tip
   Backed out changeset b2f3bb92043e
  branch: default
  commit: (clean)
  update: (current)
  phases: 6 draft

  $ cd ..

named branches

  $ hg init named_branches
  $ cd named_branches

  $ echo default > default
  $ hg ci -d '0 0' -Am default
  adding default
  $ hg branch branch1
  marked working directory as branch branch1
  (branches are permanent and global, did you want a bookmark?)
  $ echo branch1 > file1
  $ hg ci -d '1 0' -Am file1
  adding file1
  $ hg branch branch2
  marked working directory as branch branch2
  $ echo branch2 > file2
  $ hg ci -d '2 0' -Am file2
  adding file2

without --merge
  $ hg backout --no-commit -r 1 --tool=true
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  changeset bf1602f437f3 backed out, don't forget to commit.
  $ hg branch
  branch2
  $ hg status -A
  R file1
  C default
  C file2
  $ hg summary
  parent: 2:45bbcd363bf0 tip
   file2
  branch: branch2
  commit: 1 removed
  update: (current)
  phases: 3 draft

with --merge
(this also tests that editor is invoked if '--edit' is specified
explicitly regardless of '--message')

  $ hg update -qC
  $ HGEDITOR=cat hg backout --merge -d '3 0' -r 1 -m 'backout on branch1' --tool=true --edit
  removing file1
  backout on branch1
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'branch2'
  HG: removed file1
  created new head
  changeset 3:d4e8f6db59fb backs out changeset 1:bf1602f437f3
  merging with changeset 3:d4e8f6db59fb
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg summary
  parent: 2:45bbcd363bf0 
   file2
  parent: 3:d4e8f6db59fb tip
   backout on branch1
  branch: branch2
  commit: 1 removed (merge)
  update: (current)
  phases: 4 draft
  $ hg update -q -C 2

on branch2 with branch1 not merged, so file1 should still exist:

  $ hg id
  45bbcd363bf0 (branch2)
  $ hg st -A
  C default
  C file1
  C file2
  $ hg summary
  parent: 2:45bbcd363bf0 
   file2
  branch: branch2
  commit: (clean)
  update: 1 new changesets, 2 branch heads (merge)
  phases: 4 draft

on branch2 with branch1 merged, so file1 should be gone:

  $ hg merge
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -d '4 0' -m 'merge backout of branch1'
  $ hg id
  22149cdde76d (branch2) tip
  $ hg st -A
  C default
  C file2
  $ hg summary
  parent: 4:22149cdde76d tip
   merge backout of branch1
  branch: branch2
  commit: (clean)
  update: (current)
  phases: 5 draft

on branch1, so no file1 and file2:

  $ hg co -C branch1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg id
  bf1602f437f3 (branch1)
  $ hg st -A
  C default
  C file1
  $ hg summary
  parent: 1:bf1602f437f3 
   file1
  branch: branch1
  commit: (clean)
  update: (current)
  phases: 5 draft

  $ cd ..

backout of empty changeset (issue4190)

  $ hg init emptycommit
  $ cd emptycommit

  $ touch file1
  $ hg ci -Aqm file1
  $ hg branch -q branch1
  $ hg ci -qm branch1
  $ hg backout -v 1
  resolving manifests
  nothing changed
  [1]

  $ cd ..


Test usage of `hg resolve` in case of conflict
(issue4163)

  $ hg init issue4163
  $ cd issue4163
  $ touch foo
  $ hg add foo
  $ cat > foo << EOF
  > one
  > two
  > three
  > four
  > five
  > six
  > seven
  > height
  > nine
  > ten
  > EOF
  $ hg ci -m 'initial'
  $ cat > foo << EOF
  > one
  > two
  > THREE
  > four
  > five
  > six
  > seven
  > height
  > nine
  > ten
  > EOF
  $ hg ci -m 'capital three'
  $ cat > foo << EOF
  > one
  > two
  > THREE
  > four
  > five
  > six
  > seven
  > height
  > nine
  > TEN
  > EOF
  $ hg ci -m 'capital ten'
  $ hg backout -r 'desc("capital three")' --tool internal:fail
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  [1]
  $ hg status
  $ hg debugmergestate
  * version 2 records
  local: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  other: a30dd8addae3ce71b8667868478542bc417439e6
  file extras: foo (ancestorlinknode = 91360952243723bd5b1138d5f26bd8c8564cb553)
  file: foo (record type "F", state "u", hash 0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33)
    local path: foo (flags "")
    ancestor path: foo (node f89532f44c247a0e993d63e3a734dd781ab04708)
    other path: foo (node f50039b486d6fa1a90ae51778388cad161f425ee)
  $ mv .hg/merge/state2 .hg/merge/state2-moved
  $ hg debugmergestate
  * version 1 records
  local: b71750c4b0fdf719734971e3ef90dbeab5919a2d
  file: foo (record type "F", state "u", hash 0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33)
    local path: foo (flags "")
    ancestor path: foo (node f89532f44c247a0e993d63e3a734dd781ab04708)
    other path: foo (node not stored in v1 format)
  $ mv .hg/merge/state2-moved .hg/merge/state2
  $ hg resolve -l  # still unresolved
  U foo
  $ hg summary
  parent: 2:b71750c4b0fd tip
   capital ten
  branch: default
  commit: 1 unresolved (clean)
  update: (current)
  phases: 3 draft
  $ hg resolve --all --debug
  picked tool ':merge' for foo (binary False symlink False changedelete False)
  merging foo
  my foo@b71750c4b0fd+ other foo@a30dd8addae3 ancestor foo@913609522437
   premerge successful
  (no more unresolved files)
  continue: hg commit
  $ hg status
  M foo
  ? foo.orig
  $ hg resolve -l
  R foo
  $ hg summary
  parent: 2:b71750c4b0fd tip
   capital ten
  branch: default
  commit: 1 modified, 1 unknown
  update: (current)
  phases: 3 draft
  $ cat foo
  one
  two
  three
  four
  five
  six
  seven
  height
  nine
  TEN

--no-commit shouldn't commit

  $ hg init a
  $ cd a
  $ for i in 1 2 3; do
  >   touch $i
  >   hg ci -Am $i
  > done
  adding 1
  adding 2
  adding 3
  $ hg backout --no-commit .
  removing 3
  changeset cccc23d9d68f backed out, don't forget to commit.
  $ hg revert -aq

--no-commit can't be used with --merge

  $ hg backout --merge --no-commit 2
  abort: cannot use --merge with --no-commit
  [255]