view tests/test-rebase-collapse.t @ 44950:f9734b2d59cc

py3: make stdout line-buffered if connected to a TTY

Status messages that are to be shown on the terminal should be written to the
file descriptor before anything further is done, to keep the user updated.

One common way to achieve this is to make stdout line-buffered if it is
connected to a TTY. This is done on Python 2 (except on Windows, where libc,
which the CPython 2 streams depend on, does not properly support this).

Python 3 rolls it own I/O streams. On Python 3, buffered binary streams can't be
set line-buffered. The previous code (added in 227ba1afcb65) incorrectly
assumed that on Python 3, pycompat.stdout (sys.stdout.buffer) is already
line-buffered. However the interpreter initializes it with a block-buffered
stream or an unbuffered stream (when the -u option or the PYTHONUNBUFFERED
environment variable is set), never with a line-buffered stream.

One example where the current behavior is unacceptable is when running
`hg pull https://www.mercurial-scm.org/repo/hg` on Python 3, where the line
"pulling from https://www.mercurial-scm.org/repo/hg" does not appear on the
terminal before the hg process blocks while waiting for the server.

Various approaches to fix this problem are possible, including:

1. Weaken the contract of procutil.stdout to not give any guarantees about
   buffering behavior. In this case, users of procutil.stdout need to be
   changed to do enough flushes. In particular,
  1. either ui must insert enough flushes for ui.write() and friends, or
  2. ui.write() and friends get split into flushing and fully buffered
     methods, or
  3. users of ui.write() and friends must flush explicitly.
2. Make stdout unbuffered.
3. Make stdout line-buffered. Since Python 3 does not natively support that for
   binary streams, we must implement it ourselves.

(2.) is problematic because using unbuffered I/O changes the performance
characteristics significantly compared to line-buffered (which is used on
Python 2) and this would be a regression.

(1.2.) and (1.3) are a substantial amount of work. It’s unclear whether the
added complexity would be justified, given that raw performance doesn’t matter
that much when writing to a terminal much faster than the user could read it.

(1.1.) pushes complexity into the ui class instead of separating the concern of
how stdout is buffered. Other users of procutil.stdout would still need to take
care of the flushes.

This patch implements (3.). The general performance considerations are very
similar to (1.1.). The extra method invocation and method forwarding add a
little more overhead if the class is used. In exchange, it doesn’t add overhead
if not used.


For the benchmarks, I compared the previous implementation (incorrect on Python
3), (1.1.), (3.) and (2.). The command was chosen so that the streams were
configured as if they were writing to a TTY, but actually write to a pager,
which is also the default:
HGRCPATH=/dev/null python3 ./hg --cwd ~/vcs/mozilla-central --time --pager yes --config pager.pager='cat > /dev/null' status --all

previous:
time: real 7.880 secs (user 7.290+0.050 sys 0.580+0.170)
time: real 7.830 secs (user 7.220+0.070 sys 0.590+0.140)
time: real 7.800 secs (user 7.210+0.050 sys 0.570+0.170)

(1.1.) using Yuya Nishihara’s patch:
time: real 9.860 secs (user 8.670+0.350 sys 1.160+0.830)
time: real 9.540 secs (user 8.430+0.370 sys 1.100+0.770)
time: real 9.830 secs (user 8.630+0.370 sys 1.180+0.840)

(3.) using this patch:
time: real 9.580 secs (user 8.480+0.350 sys 1.090+0.770)
time: real 9.670 secs (user 8.480+0.330 sys 1.170+0.860)
time: real 9.640 secs (user 8.500+0.350 sys 1.130+0.810)

(2.) using a previous patch by me:
time: real 10.480 secs (user 8.850+0.720 sys 1.590+1.500)
time: real 10.490 secs (user 8.750+0.750 sys 1.710+1.470)
time: real 10.240 secs (user 8.600+0.700 sys 1.590+1.510)


As expected, there’s no difference on Python 2, as exactly the same code paths
are used:

previous:
time: real 6.950 secs (user 5.870+0.330 sys 1.070+0.770)
time: real 7.040 secs (user 6.040+0.360 sys 0.980+0.750)
time: real 7.070 secs (user 5.950+0.360 sys 1.100+0.760)

this patch:
time: real 7.010 secs (user 5.900+0.390 sys 1.070+0.730)
time: real 7.000 secs (user 5.850+0.350 sys 1.120+0.760)
time: real 7.000 secs (user 5.790+0.380 sys 1.170+0.710)

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > mq=
  > drawdag=$TESTDIR/drawdag.py
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
  > tglogp = log -G --template "{rev}: {node|short} {phase} '{desc}' {branches}\n"
  > EOF

Highest phase of source commits is used:

  $ hg init phase
  $ cd phase
  $ hg debugdrawdag << 'EOF'
  >   D
  >   |
  > F C
  > | |
  > E B
  > |/
  > A
  > EOF

  $ hg phase --force --secret D

  $ cat > $TESTTMP/editor.sh <<EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > echo "edited manually" >> \$1
  > EOF
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg rebase --collapse --keepbranches -e --source B --dest F
  rebasing 1:112478962961 "B" (B)
  rebasing 3:26805aba1e60 "C" (C)
  rebasing 5:f585351a92f8 "D" (D tip)
  ==== before editing
  Collapsed revision
  * B
  * C
  * D
  
  
  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 B
  HG: added C
  HG: added D
  ====
  saved backup bundle to $TESTTMP/phase/.hg/strip-backup/112478962961-cb2a9b47-rebase.hg

  $ hg tglogp
  o  3: 92fa5f5fe108 secret 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |
  |
  |  edited manually'
  o  2: 64a8289d2492 draft 'F'
  |
  o  1: 7fb047a69f22 draft 'E'
  |
  o  0: 426bada5c675 draft 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  E
  F

  $ cd ..


Merge gets linearized:

  $ hg init linearized-merge
  $ cd linearized-merge

  $ hg debugdrawdag << 'EOF'
  > F D
  > |/|
  > C B
  > |/
  > A
  > EOF

  $ hg phase --force --secret D
  $ hg rebase --source B --collapse --dest F
  rebasing 1:112478962961 "B" (B)
  rebasing 3:4e4f9194f9f1 "D" (D)
  saved backup bundle to $TESTTMP/linearized-merge/.hg/strip-backup/112478962961-e389075b-rebase.hg

  $ hg tglog
  o  3: 5bdc08b7da2b 'Collapsed revision
  |  * B
  |  * D'
  o  2: afc707c82df0 'F'
  |
  o  1: dc0947a82db8 'C'
  |
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  F

  $ cd ..

Custom message:

  $ hg init message
  $ cd message

  $ hg debugdrawdag << 'EOF'
  >   C
  >   |
  > D B
  > |/
  > A
  > EOF


  $ hg rebase --base B -m 'custom message'
  abort: message can only be specified with collapse
  [255]

  $ cat > $TESTTMP/checkeditform.sh <<EOF
  > env | grep HGEDITFORM
  > true
  > EOF
  $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg rebase --source B --collapse -m 'custom message' -e --dest D
  rebasing 1:112478962961 "B" (B)
  rebasing 3:26805aba1e60 "C" (C tip)
  HGEDITFORM=rebase.collapse
  saved backup bundle to $TESTTMP/message/.hg/strip-backup/112478962961-f4131707-rebase.hg

  $ hg tglog
  o  2: 2f197b9a08f3 'custom message'
  |
  o  1: b18e25de2cf5 'D'
  |
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D

  $ cd ..

Rebase and collapse - more than one external (fail):

  $ hg init multiple-external-parents
  $ cd multiple-external-parents

  $ hg debugdrawdag << 'EOF'
  >   G
  >   |\
  >   | F
  >   | |
  >   D E
  >   |\|
  > H C B
  >  \|/
  >   A
  > EOF

  $ hg rebase -s C --dest H --collapse
  abort: unable to collapse on top of 3, there is more than one external parent: 1, 6
  [255]

Rebase and collapse - E onto H:

  $ hg rebase -s E --dest H --collapse # root (E) is not a merge
  rebasing 5:49cb92066bfd "E" (E)
  rebasing 6:11abe3fb10b8 "F" (F)
  rebasing 7:64e264db77f0 "G" (G tip)
  saved backup bundle to $TESTTMP/multiple-external-parents/.hg/strip-backup/49cb92066bfd-ee8a8a79-rebase.hg

  $ hg tglog
  o    5: 8b2315790719 'Collapsed revision
  |\   * E
  | |  * F
  | |  * G'
  | o    4: 4e4f9194f9f1 'D'
  | |\
  o | |  3: 575c4b5ec114 'H'
  | | |
  +---o  2: dc0947a82db8 'C'
  | |
  | o  1: 112478962961 'B'
  |/
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  C
  E
  F
  H

  $ cd ..




Test that branchheads cache is updated correctly when doing a strip in which
the parent of the ancestor node to be stripped does not become a head and also,
the parent of a node that is a child of the node stripped becomes a head (node
3). The code is now much simpler and we could just test a simpler scenario
We keep it the test this way in case new complexity is injected.

Create repo b:

  $ hg init branch-heads
  $ cd branch-heads

  $ hg debugdrawdag << 'EOF'
  >   G
  >   |\
  >   | F
  >   | |
  >   D E
  >   |\|
  > H C B
  >  \|/
  >   A
  > EOF

  $ hg heads --template="{rev}:{node} {branch}\n"
  7:64e264db77f061f16d9132b70c5a58e2461fb630 default
  3:575c4b5ec114d64b681d33f8792853568bfb2b2c default

  $ cat $TESTTMP/branch-heads/.hg/cache/branch2-served
  64e264db77f061f16d9132b70c5a58e2461fb630 7
  575c4b5ec114d64b681d33f8792853568bfb2b2c o default
  64e264db77f061f16d9132b70c5a58e2461fb630 o default

  $ hg strip 4
  saved backup bundle to $TESTTMP/branch-heads/.hg/strip-backup/4e4f9194f9f1-5ec4b5e6-backup.hg

  $ cat $TESTTMP/branch-heads/.hg/cache/branch2-served
  11abe3fb10b8689b560681094b17fe161871d043 5
  dc0947a82db884575bb76ea10ac97b08536bfa03 o default
  575c4b5ec114d64b681d33f8792853568bfb2b2c o default
  11abe3fb10b8689b560681094b17fe161871d043 o default

  $ hg heads --template="{rev}:{node} {branch}\n"
  5:11abe3fb10b8689b560681094b17fe161871d043 default
  3:575c4b5ec114d64b681d33f8792853568bfb2b2c default
  2:dc0947a82db884575bb76ea10ac97b08536bfa03 default

  $ cd ..



Preserves external parent

  $ hg init external-parent
  $ cd external-parent

  $ hg debugdrawdag << 'EOF'
  >   H
  >   |\
  >   | G
  >   | |
  >   | F # F/E = F\n
  >   | |
  >   D E # D/D = D\n
  >   |\|
  > I C B
  >  \|/
  >   A
  > EOF

  $ hg rebase -s F --dest I --collapse # root (F) is not a merge
  rebasing 6:c82b08f646f1 "F" (F)
  file 'E' was deleted in local [dest] but was modified in other [source].
  You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.
  What do you want to do? u
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ echo F > E
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase -c
  rebasing 6:c82b08f646f1 "F" (F)
  rebasing 7:a6db7fa104e1 "G" (G)
  rebasing 8:e1d201b72d91 "H" (H tip)
  saved backup bundle to $TESTTMP/external-parent/.hg/strip-backup/c82b08f646f1-f2721fbf-rebase.hg

  $ hg tglog
  o    6: 681daa3e686d 'Collapsed revision
  |\   * F
  | |  * G
  | |  * H'
  | | o  5: 49cb92066bfd 'E'
  | | |
  | o |  4: 09143c0bf13e 'D'
  | |\|
  o | |  3: 08ebfeb61bac 'I'
  | | |
  | o |  2: dc0947a82db8 'C'
  |/ /
  | o  1: 112478962961 'B'
  |/
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  C
  D
  E
  F
  G
  I

  $ hg up tip -q
  $ cat E
  F

  $ cd ..

Rebasing from multiple bases:

  $ hg init multiple-bases
  $ cd multiple-bases
  $ hg debugdrawdag << 'EOF'
  >   C B
  > D |/
  > |/
  > A
  > EOF
  $ hg rebase --collapse -r 'B+C' -d D
  rebasing 1:fc2b737bb2e5 "B" (B)
  rebasing 2:dc0947a82db8 "C" (C)
  saved backup bundle to $TESTTMP/multiple-bases/.hg/strip-backup/dc0947a82db8-b0c1a7ea-rebase.hg
  $ hg tglog
  o  2: 2127ae44d291 'Collapsed revision
  |  * B
  |  * C'
  o  1: b18e25de2cf5 'D'
  |
  o  0: 426bada5c675 'A'
  
  $ cd ..

With non-contiguous commits:

  $ hg init non-contiguous
  $ cd non-contiguous
  $ cat >> .hg/hgrc <<EOF
  > [experimental]
  > evolution=all
  > EOF

  $ hg debugdrawdag << 'EOF'
  > F
  > |
  > E
  > |
  > D
  > |
  > C
  > |
  > B G
  > |/
  > A
  > EOF

BROKEN: should be allowed
  $ hg rebase --collapse -r 'B+D+F' -d G
  abort: unable to collapse on top of 2, there is more than one external parent: 3, 5
  [255]
  $ cd ..


  $ hg init multiple-external-parents-2
  $ cd multiple-external-parents-2
  $ hg debugdrawdag << 'EOF'
  > D       G
  > |\     /|
  > B C   E F
  >  \|   |/
  >   \ H /
  >    \|/
  >     A
  > EOF

  $ hg rebase --collapse -d H -s 'B+F'
  abort: unable to collapse on top of 5, there is more than one external parent: 1, 3
  [255]
  $ cd ..

With internal merge:

  $ hg init internal-merge
  $ cd internal-merge

  $ hg debugdrawdag << 'EOF'
  >   E
  >   |\
  >   C D
  >   |/
  > F B
  > |/
  > A
  > EOF


  $ hg rebase -s B --collapse --dest F
  rebasing 1:112478962961 "B" (B)
  rebasing 3:26805aba1e60 "C" (C)
  rebasing 4:be0ef73c17ad "D" (D)
  rebasing 5:02c4367d6973 "E" (E tip)
  saved backup bundle to $TESTTMP/internal-merge/.hg/strip-backup/112478962961-1dfb057b-rebase.hg

  $ hg tglog
  o  2: c0512a1797b0 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |  * E'
  o  1: 8908a377a434 'F'
  |
  o  0: 426bada5c675 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  F
  $ cd ..

Interactions between collapse and keepbranches
  $ hg init e
  $ cd e
  $ echo 'a' > a
  $ hg ci -Am 'A'
  adding a

  $ hg branch 'one'
  marked working directory as branch one
  (branches are permanent and global, did you want a bookmark?)
  $ echo 'b' > b
  $ hg ci -Am 'B'
  adding b

  $ hg branch 'two'
  marked working directory as branch two
  $ echo 'c' > c
  $ hg ci -Am 'C'
  adding c

  $ hg up -q 0
  $ echo 'd' > d
  $ hg ci -Am 'D'
  adding d

  $ hg tglog
  @  3: 41acb9dca9eb 'D'
  |
  | o  2: 8ac4a08debf1 'C' two
  | |
  | o  1: 1ba175478953 'B' one
  |/
  o  0: 1994f17a630e 'A'
  
  $ hg rebase --keepbranches --collapse -s 1 -d 3
  abort: cannot collapse multiple named branches
  [255]

  $ cd ..

Rebase, collapse and copies

  $ hg init copies
  $ cd copies
  $ hg unbundle "$TESTDIR/bundles/renames.hg"
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 11 changes to 7 files (+1 heads)
  new changesets f447d5abf5ea:338e84e2e558 (4 drafts)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up -q tip
  $ hg tglog
  @  3: 338e84e2e558 'move2'
  |
  o  2: 6e7340ee38c0 'move1'
  |
  | o  1: 1352765a01d4 'change'
  |/
  o  0: f447d5abf5ea 'add'
  
  $ hg rebase --collapse -d 1
  rebasing 2:6e7340ee38c0 "move1"
  merging a and d to d
  merging b and e to e
  merging c and f to f
  rebasing 3:338e84e2e558 "move2" (tip)
  merging f and c to c
  merging e and g to g
  saved backup bundle to $TESTTMP/copies/.hg/strip-backup/6e7340ee38c0-ef8ef003-rebase.hg
  $ hg st
  $ hg st --copies --change tip
  A d
    a
  A g
    b
  R b
  $ hg up tip -q
  $ cat c
  c
  c
  $ cat d
  a
  a
  $ cat g
  b
  b
  $ hg log -r . --template "{file_copies}\n"
  d (a)g (b)

Test collapsing a middle revision in-place

  $ hg tglog
  @  2: 64b456429f67 'Collapsed revision
  |  * move1
  |  * move2'
  o  1: 1352765a01d4 'change'
  |
  o  0: f447d5abf5ea 'add'
  
  $ hg rebase --collapse -r 1 -d 0
  abort: cannot rebase changeset with children
  (use --keep to keep original changesets)
  [255]

Test collapsing in place

  $ hg rebase --collapse -b . -d 0
  rebasing 1:1352765a01d4 "change"
  rebasing 2:64b456429f67 "Collapsed revision" (tip)
  saved backup bundle to $TESTTMP/copies/.hg/strip-backup/1352765a01d4-45a352ea-rebase.hg
  $ hg st --change tip --copies
  M a
  M c
  A d
    a
  A g
    b
  R b
  $ hg up tip -q
  $ cat a
  a
  a
  $ cat c
  c
  c
  $ cat d
  a
  a
  $ cat g
  b
  b
  $ cd ..


Test stripping a revision with another child

  $ hg init f
  $ cd f

  $ hg debugdrawdag << 'EOF'
  > C B
  > |/
  > A
  > EOF

  $ hg heads --template="{rev}:{node} {branch}: {desc}\n"
  2:dc0947a82db884575bb76ea10ac97b08536bfa03 default: C
  1:112478962961147124edd43549aedd1a335e44bf default: B

  $ hg strip C
  saved backup bundle to $TESTTMP/f/.hg/strip-backup/dc0947a82db8-d21b92a4-backup.hg

  $ hg tglog
  o  1: 112478962961 'B'
  |
  o  0: 426bada5c675 'A'
  


  $ hg heads --template="{rev}:{node} {branch}: {desc}\n"
  1:112478962961147124edd43549aedd1a335e44bf default: B

  $ cd ..

Test collapsing changes that add then remove a file

  $ hg init collapseaddremove
  $ cd collapseaddremove

  $ touch base
  $ hg commit -Am base
  adding base
  $ touch a
  $ hg commit -Am a
  adding a
  $ hg rm a
  $ touch b
  $ hg commit -Am b
  adding b
  $ hg book foo
  $ hg rebase -d 0 -r "1::2" --collapse -m collapsed
  rebasing 1:6d8d9f24eec3 "a"
  rebasing 2:1cc73eca5ecc "b" (foo tip)
  saved backup bundle to $TESTTMP/collapseaddremove/.hg/strip-backup/6d8d9f24eec3-77d3b6e2-rebase.hg
  $ hg log -G --template "{rev}: '{desc}' {bookmarks}"
  @  1: 'collapsed' foo
  |
  o  0: 'base'
  
  $ hg manifest --rev tip
  b
  base

  $ cd ..

Test that rebase --collapse will remember message after
running into merge conflict and invoking rebase --continue.

  $ hg init collapse_remember_message
  $ cd collapse_remember_message
  $ hg debugdrawdag << 'EOF'
  > C B # B/A = B\n
  > |/  # C/A = C\n
  > A
  > EOF
  $ hg rebase --collapse -m "new message" -b B -d C
  rebasing 1:81e5401e4d37 "B" (B)
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ rm A.orig
  $ hg resolve --mark A
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 1:81e5401e4d37 "B" (B)
  saved backup bundle to $TESTTMP/collapse_remember_message/.hg/strip-backup/81e5401e4d37-96c3dd30-rebase.hg
  $ hg log
  changeset:   2:17186933e123
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new message
  
  changeset:   1:043039e9df84
  tag:         C
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     C
  
  changeset:   0:426bada5c675
  tag:         A
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     A
  
  $ cd ..

Test aborted editor on final message

  $ HGMERGE=:merge3
  $ export HGMERGE
  $ hg init aborted-editor
  $ cd aborted-editor
  $ hg debugdrawdag << 'EOF'
  > C   # D/A = D\n
  > |   # C/A = C\n
  > B D # B/A = B\n
  > |/  # A/A = A\n
  > A
  > EOF
  $ hg rebase --collapse -t internal:merge3 -s B -d D
  rebasing 1:f899f3910ce7 "B" (B)
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ hg tglog
  o  3: 63668d570d21 'C'
  |
  | @  2: 82b8abf9c185 'D'
  | |
  % |  1: f899f3910ce7 'B'
  |/
  o  0: 4a2df7238c3b 'A'
  
  $ cat A
  <<<<<<< dest:   82b8abf9c185 D - test: D
  D
  ||||||| base
  A
  =======
  B
  >>>>>>> source: f899f3910ce7 B - test: B
  $ echo BC > A
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 1:f899f3910ce7 "B" (B)
  rebasing 3:63668d570d21 "C" (C tip)
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ hg tglog
  %  3: 63668d570d21 'C'
  |
  | @  2: 82b8abf9c185 'D'
  | |
  o |  1: f899f3910ce7 'B'
  |/
  o  0: 4a2df7238c3b 'A'
  
  $ cat A
  <<<<<<< dest:   82b8abf9c185 D - test: D
  BC
  ||||||| base
  B
  =======
  C
  >>>>>>> source: 63668d570d21 C tip - test: C
  $ echo BD > A
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ HGEDITOR=false hg rebase --continue --config ui.interactive=1
  already rebased 1:f899f3910ce7 "B" (B) as 82b8abf9c185
  rebasing 3:63668d570d21 "C" (C tip)
  abort: edit failed: false exited with status 1
  [255]
  $ hg tglog
  %  3: 63668d570d21 'C'
  |
  | @  2: 82b8abf9c185 'D'
  | |
  o |  1: f899f3910ce7 'B'
  |/
  o  0: 4a2df7238c3b 'A'
  
  $ hg rebase --continue
  already rebased 1:f899f3910ce7 "B" (B) as 82b8abf9c185
  already rebased 3:63668d570d21 "C" (C tip) as 82b8abf9c185
  saved backup bundle to $TESTTMP/aborted-editor/.hg/strip-backup/f899f3910ce7-7cab5e15-rebase.hg