tests/test-split.t
author Augie Fackler <augie@google.com>
Mon, 08 Jul 2019 13:12:20 -0400
branchstable
changeset 42562 97ada9b8d51b
parent 41982 f8c5225b9054
child 42566 f802a75da585
permissions -rw-r--r--
posix: always seek to EOF when opening a file in append mode Python 3 already does this, so skip it there. Consider the program: #include <stdio.h> int main() { FILE *f = fopen("narf", "w"); fprintf(f, "narf\n"); fclose(f); f = fopen("narf", "a"); printf("%ld\n", ftell(f)); fprintf(f, "troz\n"); printf("%ld\n", ftell(f)); return 0; } on macOS, FreeBSD, and Linux with glibc, this program prints 5 10 but on musl libc (Alpine Linux and probably others) this prints 0 10 By my reading of https://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html this is technically correct, specifically: > Opening a file with append mode (a as the first character in the > mode argument) shall cause all subsequent writes to the file to be > forced to the then current end-of-file, regardless of intervening > calls to fseek(). in other words, the file position doesn't really matter in append-mode files, and we can't depend on it being at all meaningful unless we perform a seek() before tell() after open(..., 'a'). Experimentally after a .write() we can do a .tell() and it'll always be reasonable, but I'm unclear from reading the specification if that's a smart thing to rely on. This matches what we do on Windows and what Python 3 does for free, so let's just be consistent. Thanks to Yuya for the idea.

#testcases obsstore-on obsstore-off

  $ cat > $TESTTMP/editor.py <<EOF
  > #!"$PYTHON"
  > import os
  > import sys
  > path = os.path.join(os.environ['TESTTMP'], 'messages')
  > messages = open(path).read().split('--\n')
  > prompt = open(sys.argv[1]).read()
  > sys.stdout.write(''.join('EDITOR: %s' % l for l in prompt.splitlines(True)))
  > sys.stdout.flush()
  > with open(sys.argv[1], 'w') as f:
  >    f.write(messages[0])
  > with open(path, 'w') as f:
  >    f.write('--\n'.join(messages[1:]))
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > drawdag=$TESTDIR/drawdag.py
  > split=
  > [ui]
  > interactive=1
  > color=no
  > paginate=never
  > [diff]
  > git=1
  > unified=0
  > [commands]
  > commit.interactive.unified=0
  > [alias]
  > glog=log -G -T '{rev}:{node|short} {desc} {bookmarks}\n'
  > EOF

#if obsstore-on
  $ cat >> $HGRCPATH <<EOF
  > [experimental]
  > evolution=all
  > EOF
#endif

  $ hg init a
  $ cd a

Nothing to split

  $ hg split
  nothing to split
  [1]

  $ hg commit -m empty --config ui.allowemptycommit=1
  $ hg split
  abort: cannot split an empty revision
  [255]

  $ rm -rf .hg
  $ hg init

Cannot split working directory

  $ hg split -r 'wdir()'
  abort: cannot split working directory
  [255]

Generate some content.  The sed filter drop CR on Windows, which is dropped in
the a > b line.

  $ $TESTDIR/seq.py 1 5 | sed 's/\r$//' >> a
  $ hg ci -m a1 -A a -q
  $ hg bookmark -i r1
  $ sed 's/1/11/;s/3/33/;s/5/55/' a > b
  $ mv b a
  $ hg ci -m a2 -q
  $ hg bookmark -i r2

Cannot split a public changeset

  $ hg phase --public -r 'all()'
  $ hg split .
  abort: cannot split public changeset
  (see 'hg help phases' for details)
  [255]

  $ hg phase --draft -f -r 'all()'

Cannot split while working directory is dirty

  $ touch dirty
  $ hg add dirty
  $ hg split .
  abort: uncommitted changes
  [255]
  $ hg forget dirty
  $ rm dirty

Make a clean directory for future tests to build off of

  $ cp -R . ../clean

Split a head

  $ hg bookmark r3

  $ hg split 'all()'
  abort: cannot split multiple revisions
  [255]

This function splits a bit strangely primarily to avoid changing the behavior of
the test after a bug was fixed with how split/commit --interactive handled
`commands.commit.interactive.unified=0`: when there were no context lines,
it kept only the last diff hunk. When running split, this meant that runsplit
was always recording three commits, one for each diff hunk, in reverse order
(the base commit was the last diff hunk in the file).
  $ runsplit() {
  > cat > $TESTTMP/messages <<EOF
  > split 1
  > --
  > split 2
  > --
  > split 3
  > EOF
  > cat <<EOF | hg split "$@"
  > y
  > n
  > n
  > y
  > y
  > n
  > y
  > y
  > y
  > EOF
  > }

  $ HGEDITOR=false runsplit
  diff --git a/a b/a
  3 hunks, 3 lines changed
  examine changes to 'a'? [Ynesfdaq?] y
  
  @@ -1,1 +1,1 @@
  -1
  +11
  record change 1/3 to 'a'? [Ynesfdaq?] n
  
  @@ -3,1 +3,1 @@ 2
  -3
  +33
  record change 2/3 to 'a'? [Ynesfdaq?] n
  
  @@ -5,1 +5,1 @@ 4
  -5
  +55
  record change 3/3 to 'a'? [Ynesfdaq?] y
  
  transaction abort!
  rollback completed
  abort: edit failed: false exited with status 1
  [255]
  $ hg status

  $ HGEDITOR="\"$PYTHON\" $TESTTMP/editor.py"
  $ runsplit
  diff --git a/a b/a
  3 hunks, 3 lines changed
  examine changes to 'a'? [Ynesfdaq?] y
  
  @@ -1,1 +1,1 @@
  -1
  +11
  record change 1/3 to 'a'? [Ynesfdaq?] n
  
  @@ -3,1 +3,1 @@ 2
  -3
  +33
  record change 2/3 to 'a'? [Ynesfdaq?] n
  
  @@ -5,1 +5,1 @@ 4
  -5
  +55
  record change 3/3 to 'a'? [Ynesfdaq?] y
  
  EDITOR: HG: Splitting 1df0d5c5a3ab. Write commit message for the first split changeset.
  EDITOR: a2
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed a
  created new head
  diff --git a/a b/a
  2 hunks, 2 lines changed
  examine changes to 'a'? [Ynesfdaq?] y
  
  @@ -1,1 +1,1 @@
  -1
  +11
  record change 1/2 to 'a'? [Ynesfdaq?] n
  
  @@ -3,1 +3,1 @@ 2
  -3
  +33
  record change 2/2 to 'a'? [Ynesfdaq?] y
  
  EDITOR: HG: Splitting 1df0d5c5a3ab. So far it has been split into:
  EDITOR: HG: - e704349bd21b: split 1
  EDITOR: HG: Write commit message for the next split changeset.
  EDITOR: a2
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed a
  diff --git a/a b/a
  1 hunks, 1 lines changed
  examine changes to 'a'? [Ynesfdaq?] y
  
  @@ -1,1 +1,1 @@
  -1
  +11
  record this change to 'a'? [Ynesfdaq?] y
  
  EDITOR: HG: Splitting 1df0d5c5a3ab. So far it has been split into:
  EDITOR: HG: - e704349bd21b: split 1
  EDITOR: HG: - a09ad58faae3: split 2
  EDITOR: HG: Write commit message for the next split changeset.
  EDITOR: a2
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed a
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/1df0d5c5a3ab-8341b760-split.hg (obsstore-off !)

#if obsstore-off
  $ hg bookmark
     r1                        0:a61bcde8c529
     r2                        3:00eebaf8d2e2
   * r3                        3:00eebaf8d2e2
  $ hg glog -p
  @  3:00eebaf8d2e2 split 3 r2 r3
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -1,1 +1,1 @@
  |  -1
  |  +11
  |
  o  2:a09ad58faae3 split 2
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -3,1 +3,1 @@
  |  -3
  |  +33
  |
  o  1:e704349bd21b split 1
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -5,1 +5,1 @@
  |  -5
  |  +55
  |
  o  0:a61bcde8c529 a1 r1
     diff --git a/a b/a
     new file mode 100644
     --- /dev/null
     +++ b/a
     @@ -0,0 +1,5 @@
     +1
     +2
     +3
     +4
     +5
  
#else
  $ hg bookmark
     r1                        0:a61bcde8c529
     r2                        4:00eebaf8d2e2
   * r3                        4:00eebaf8d2e2
  $ hg glog
  @  4:00eebaf8d2e2 split 3 r2 r3
  |
  o  3:a09ad58faae3 split 2
  |
  o  2:e704349bd21b split 1
  |
  o  0:a61bcde8c529 a1 r1
  
#endif

Split a head while working parent is not that head

  $ cp -R $TESTTMP/clean $TESTTMP/b
  $ cd $TESTTMP/b

  $ hg up 0 -q
  $ hg bookmark r3

  $ runsplit tip >/dev/null

#if obsstore-off
  $ hg bookmark
     r1                        0:a61bcde8c529
     r2                        3:00eebaf8d2e2
   * r3                        0:a61bcde8c529
  $ hg glog
  o  3:00eebaf8d2e2 split 3 r2
  |
  o  2:a09ad58faae3 split 2
  |
  o  1:e704349bd21b split 1
  |
  @  0:a61bcde8c529 a1 r1 r3
  
#else
  $ hg bookmark
     r1                        0:a61bcde8c529
     r2                        4:00eebaf8d2e2
   * r3                        0:a61bcde8c529
  $ hg glog
  o  4:00eebaf8d2e2 split 3 r2
  |
  o  3:a09ad58faae3 split 2
  |
  o  2:e704349bd21b split 1
  |
  @  0:a61bcde8c529 a1 r1 r3
  
#endif

Split a non-head

  $ cp -R $TESTTMP/clean $TESTTMP/c
  $ cd $TESTTMP/c
  $ echo d > d
  $ hg ci -m d1 -A d
  $ hg bookmark -i d1
  $ echo 2 >> d
  $ hg ci -m d2
  $ echo 3 >> d
  $ hg ci -m d3
  $ hg bookmark -i d3
  $ hg up '.^' -q
  $ hg bookmark d2
  $ cp -R . ../d

  $ runsplit -r 1 | grep rebasing
  rebasing 2:b5c5ea414030 "d1" (d1)
  rebasing 3:f4a0a8d004cc "d2" (d2)
  rebasing 4:777940761eba "d3" (d3)
#if obsstore-off
  $ hg bookmark
     d1                        4:c4b449ef030e
   * d2                        5:c9dd00ab36a3
     d3                        6:19f476bc865c
     r1                        0:a61bcde8c529
     r2                        3:00eebaf8d2e2
  $ hg glog -p
  o  6:19f476bc865c d3 d3
  |  diff --git a/d b/d
  |  --- a/d
  |  +++ b/d
  |  @@ -2,0 +3,1 @@
  |  +3
  |
  @  5:c9dd00ab36a3 d2 d2
  |  diff --git a/d b/d
  |  --- a/d
  |  +++ b/d
  |  @@ -1,0 +2,1 @@
  |  +2
  |
  o  4:c4b449ef030e d1 d1
  |  diff --git a/d b/d
  |  new file mode 100644
  |  --- /dev/null
  |  +++ b/d
  |  @@ -0,0 +1,1 @@
  |  +d
  |
  o  3:00eebaf8d2e2 split 3 r2
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -1,1 +1,1 @@
  |  -1
  |  +11
  |
  o  2:a09ad58faae3 split 2
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -3,1 +3,1 @@
  |  -3
  |  +33
  |
  o  1:e704349bd21b split 1
  |  diff --git a/a b/a
  |  --- a/a
  |  +++ b/a
  |  @@ -5,1 +5,1 @@
  |  -5
  |  +55
  |
  o  0:a61bcde8c529 a1 r1
     diff --git a/a b/a
     new file mode 100644
     --- /dev/null
     +++ b/a
     @@ -0,0 +1,5 @@
     +1
     +2
     +3
     +4
     +5
  
#else
  $ hg bookmark
     d1                        8:c4b449ef030e
   * d2                        9:c9dd00ab36a3
     d3                        10:19f476bc865c
     r1                        0:a61bcde8c529
     r2                        7:00eebaf8d2e2
  $ hg glog
  o  10:19f476bc865c d3 d3
  |
  @  9:c9dd00ab36a3 d2 d2
  |
  o  8:c4b449ef030e d1 d1
  |
  o  7:00eebaf8d2e2 split 3 r2
  |
  o  6:a09ad58faae3 split 2
  |
  o  5:e704349bd21b split 1
  |
  o  0:a61bcde8c529 a1 r1
  
#endif

Split a non-head without rebase

  $ cd $TESTTMP/d
#if obsstore-off
  $ runsplit -r 1 --no-rebase
  abort: cannot split changeset with children without rebase
  [255]
#else
  $ runsplit -r 1 --no-rebase >/dev/null
  3 new orphan changesets
  $ hg bookmark
     d1                        2:b5c5ea414030
   * d2                        3:f4a0a8d004cc
     d3                        4:777940761eba
     r1                        0:a61bcde8c529
     r2                        7:00eebaf8d2e2

  $ hg glog
  o  7:00eebaf8d2e2 split 3 r2
  |
  o  6:a09ad58faae3 split 2
  |
  o  5:e704349bd21b split 1
  |
  | *  4:777940761eba d3 d3
  | |
  | @  3:f4a0a8d004cc d2 d2
  | |
  | *  2:b5c5ea414030 d1 d1
  | |
  | x  1:1df0d5c5a3ab a2
  |/
  o  0:a61bcde8c529 a1 r1
  
#endif

Split a non-head with obsoleted descendants

#if obsstore-on
  $ hg init $TESTTMP/e
  $ cd $TESTTMP/e
  $ hg debugdrawdag <<'EOS'
  >   H I   J
  >   | |   |
  >   F G1 G2  # amend: G1 -> G2
  >   | |  /   # prune: F
  >   C D E
  >    \|/
  >     B
  >     |
  >     A
  > EOS
  2 new orphan changesets
  $ eval `hg tags -T '{tag}={node}\n'`
  $ rm .hg/localtags
  $ hg split $B --config experimental.evolution=createmarkers
  abort: split would leave orphaned changesets behind
  [255]
  $ cat > $TESTTMP/messages <<EOF
  > Split B
  > EOF
  $ cat <<EOF | hg split $B
  > y
  > y
  > EOF
  diff --git a/B b/B
  new file mode 100644
  examine changes to 'B'? [Ynesfdaq?] y
  
  @@ -0,0 +1,1 @@
  +B
  \ No newline at end of file
  record this change to 'B'? [Ynesfdaq?] y
  
  EDITOR: HG: Splitting 112478962961. Write commit message for the first split changeset.
  EDITOR: B
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: added B
  created new head
  rebasing 2:26805aba1e60 "C"
  rebasing 3:be0ef73c17ad "D"
  rebasing 4:49cb92066bfd "E"
  rebasing 7:97a6268cc7ef "G2"
  rebasing 10:e2f1e425c0db "J"
  $ hg glog -r 'sort(all(), topo)'
  o  16:556c085f8b52 J
  |
  o  15:8761f6c9123f G2
  |
  o  14:a7aeffe59b65 E
  |
  | o  13:e1e914ede9ab D
  |/
  | o  12:01947e9b98aa C
  |/
  o  11:0947baa74d47 Split B
  |
  | *  9:88ede1d5ee13 I
  | |
  | x  6:af8cbf225b7b G1
  | |
  | x  3:be0ef73c17ad D
  | |
  | | *  8:74863e5b5074 H
  | | |
  | | x  5:ee481a2a1e69 F
  | | |
  | | x  2:26805aba1e60 C
  | |/
  | x  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
#endif

Preserve secret phase in split

  $ cp -R $TESTTMP/clean $TESTTMP/phases1
  $ cd $TESTTMP/phases1
  $ hg phase --secret -fr tip
  $ hg log -T '{short(node)} {phase}\n'
  1df0d5c5a3ab secret
  a61bcde8c529 draft
  $ runsplit tip >/dev/null
  $ hg log -T '{short(node)} {phase}\n'
  00eebaf8d2e2 secret
  a09ad58faae3 secret
  e704349bd21b secret
  a61bcde8c529 draft

Do not move things to secret even if phases.new-commit=secret

  $ cp -R $TESTTMP/clean $TESTTMP/phases2
  $ cd $TESTTMP/phases2
  $ cat >> .hg/hgrc <<EOF
  > [phases]
  > new-commit=secret
  > EOF
  $ hg log -T '{short(node)} {phase}\n'
  1df0d5c5a3ab draft
  a61bcde8c529 draft
  $ runsplit tip >/dev/null
  $ hg log -T '{short(node)} {phase}\n'
  00eebaf8d2e2 draft
  a09ad58faae3 draft
  e704349bd21b draft
  a61bcde8c529 draft

`hg split` with ignoreblanklines=1 does not infinite loop

  $ mkdir $TESTTMP/f
  $ hg init $TESTTMP/f/a
  $ cd $TESTTMP/f/a
  $ printf '1\n2\n3\n4\n5\n' > foo
  $ cp foo bar
  $ hg ci -qAm initial
  $ printf '1\n\n2\n3\ntest\n4\n5\n' > bar
  $ printf '1\n2\n3\ntest\n4\n5\n' > foo
  $ hg ci -qm splitme
  $ cat > $TESTTMP/messages <<EOF
  > split 1
  > --
  > split 2
  > EOF
  $ printf 'f\nn\nf\n' | hg --config extensions.split= --config diff.ignoreblanklines=1 split
  diff --git a/bar b/bar
  2 hunks, 2 lines changed
  examine changes to 'bar'? [Ynesfdaq?] f
  
  diff --git a/foo b/foo
  1 hunks, 1 lines changed
  examine changes to 'foo'? [Ynesfdaq?] n
  
  EDITOR: HG: Splitting dd3c45017cbf. Write commit message for the first split changeset.
  EDITOR: splitme
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed bar
  created new head
  diff --git a/foo b/foo
  1 hunks, 1 lines changed
  examine changes to 'foo'? [Ynesfdaq?] f
  
  EDITOR: HG: Splitting dd3c45017cbf. So far it has been split into:
  EDITOR: HG: - f205aea1c624: split 1
  EDITOR: HG: Write commit message for the next split changeset.
  EDITOR: splitme
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed foo
  saved backup bundle to $TESTTMP/f/a/.hg/strip-backup/dd3c45017cbf-463441b5-split.hg (obsstore-off !)

Let's try that again, with a slightly different set of patches, to ensure that
the ignoreblanklines thing isn't somehow position dependent.

  $ hg init $TESTTMP/f/b
  $ cd $TESTTMP/f/b
  $ printf '1\n2\n3\n4\n5\n' > foo
  $ cp foo bar
  $ hg ci -qAm initial
  $ printf '1\n2\n3\ntest\n4\n5\n' > bar
  $ printf '1\n2\n3\ntest\n4\n\n5\n' > foo
  $ hg ci -qm splitme
  $ cat > $TESTTMP/messages <<EOF
  > split 1
  > --
  > split 2
  > EOF
  $ printf 'f\nn\nf\n' | hg --config extensions.split= --config diff.ignoreblanklines=1 split
  diff --git a/bar b/bar
  1 hunks, 1 lines changed
  examine changes to 'bar'? [Ynesfdaq?] f
  
  diff --git a/foo b/foo
  2 hunks, 2 lines changed
  examine changes to 'foo'? [Ynesfdaq?] n
  
  EDITOR: HG: Splitting 904c80b40a4a. Write commit message for the first split changeset.
  EDITOR: splitme
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed bar
  created new head
  diff --git a/foo b/foo
  2 hunks, 2 lines changed
  examine changes to 'foo'? [Ynesfdaq?] f
  
  EDITOR: HG: Splitting 904c80b40a4a. So far it has been split into:
  EDITOR: HG: - ffecf40fa954: split 1
  EDITOR: HG: Write commit message for the next split changeset.
  EDITOR: splitme
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed foo
  saved backup bundle to $TESTTMP/f/b/.hg/strip-backup/904c80b40a4a-47fb907f-split.hg (obsstore-off !)


Testing the case in split when commiting flag-only file changes (issue5864)
---------------------------------------------------------------------------
  $ hg init $TESTTMP/issue5864
  $ cd $TESTTMP/issue5864
  $ echo foo > foo
  $ hg add foo
  $ hg ci -m "initial"
  $ hg import -q --bypass -m "make executable" - <<EOF
  > diff --git a/foo b/foo
  > old mode 100644
  > new mode 100755
  > EOF
  $ hg up -q

  $ hg glog
  @  1:3a2125f0f4cb make executable
  |
  o  0:51f273a58d82 initial
  

#if no-windows
  $ cat > $TESTTMP/messages <<EOF
  > split 1
  > EOF
  $ printf 'y\n' | hg split
  diff --git a/foo b/foo
  old mode 100644
  new mode 100755
  examine changes to 'foo'? [Ynesfdaq?] y
  
  EDITOR: HG: Splitting 3a2125f0f4cb. Write commit message for the first split changeset.
  EDITOR: make executable
  EDITOR: 
  EDITOR: 
  EDITOR: HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  EDITOR: HG: Leave message empty to abort commit.
  EDITOR: HG: --
  EDITOR: HG: user: test
  EDITOR: HG: branch 'default'
  EDITOR: HG: changed foo
  created new head
  saved backup bundle to $TESTTMP/issue5864/.hg/strip-backup/3a2125f0f4cb-629e4432-split.hg (obsstore-off !)

  $ hg log -G -T "{node|short} {desc}\n"
  @  b154670c87da split 1
  |
  o  51f273a58d82 initial
  
#else

TODO: Fix this on Windows. See issue 2020 and 5883

  $ printf 'y\ny\ny\n' | hg split
  abort: cannot split an empty revision
  [255]
#endif