view tests/test-rebase-dest.t @ 42943:5fadf6103790

remotefilelog: replace repack lock to solve race condition

2c74337e6483 reduced the probability of race-conditions when starting
background repack and prefetch and we saw the difference in our CI instance
with all failures disappearing except one where one call to waitonrepack seems
to returns too early.

I'm not sure what exactly goes wrong but I realized that while the prefetch
operation uses a standard Mercurial lock, the repack operation is using a
custom lock based on `fcntl.flock` on available platforms. As `extutil.flock`
fallback on traditional Mercurial locks on other platforms and the tests are
stable on my laptop, our CI environment and GCC112, I'm sending this patch to
standardize the behavior across environments.

Differential Revision: https://phab.mercurial-scm.org/D6844

Require a destination
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase =
  > [commands]
  > rebase.requiredest = True
  > EOF
  $ hg init repo
  $ cd repo
  $ echo a >> a
  $ hg commit -qAm aa
  $ echo b >> b
  $ hg commit -qAm bb
  $ hg up ".^"
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo c >> c
  $ hg commit -qAm cc
  $ hg rebase
  abort: you must specify a destination
  (use: hg rebase -d REV)
  [255]
  $ hg rebase -d 1
  rebasing 2:5db65b93a12b "cc" (tip)
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/5db65b93a12b-4fb789ec-rebase.hg
  $ hg rebase -d 0 -r . -q
  $ HGPLAIN=1 hg rebase
  rebasing 2:889b0bc6a730 "cc" (tip)
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/889b0bc6a730-41ec4f81-rebase.hg
  $ hg rebase -d 0 -r . -q
  $ hg --config commands.rebase.requiredest=False rebase
  rebasing 2:279de9495438 "cc" (tip)
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/279de9495438-ab0a5128-rebase.hg

Requiring dest should not break continue or other rebase options
  $ hg up 1 -q
  $ echo d >> c
  $ hg commit -qAm dc
  $ hg log -G -T '{rev} {desc}'
  @  3 dc
  |
  | o  2 cc
  |/
  o  1 bb
  |
  o  0 aa
  
  $ hg rebase -d 2
  rebasing 3:0537f6b50def "dc" (tip)
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ echo d > c
  $ hg resolve --mark --all
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 3:0537f6b50def "dc" (tip)
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/0537f6b50def-be4c7386-rebase.hg

  $ cd ..

Check rebase.requiredest interaction with pull --rebase
  $ hg clone repo clone
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd repo
  $ echo e > e
  $ hg commit -qAm ee
  $ cd ..
  $ cd clone
  $ echo f > f
  $ hg commit -qAm ff
  $ hg pull --rebase
  abort: rebase destination required by configuration
  (use hg pull followed by hg rebase -d DEST)
  [255]

Setup rebase with multiple destinations

  $ cd $TESTTMP

  $ cat >> $TESTTMP/maprevset.py <<EOF
  > from __future__ import absolute_import
  > from mercurial import registrar, revset, revsetlang, smartset
  > revsetpredicate = registrar.revsetpredicate()
  > cache = {}
  > @revsetpredicate(b'map')
  > def map(repo, subset, x):
  >     """(set, mapping)"""
  >     setarg, maparg = revsetlang.getargs(x, 2, 2, b'')
  >     rset = revset.getset(repo, smartset.fullreposet(repo), setarg)
  >     mapstr = revsetlang.getstring(maparg, b'')
  >     map = dict(a.split(b':') for a in mapstr.split(b','))
  >     rev = rset.first()
  >     desc = repo[rev].description()
  >     newdesc = map.get(desc)
  >     if newdesc == b'null':
  >         revs = [-1]
  >     else:
  >         query = revsetlang.formatspec(b'desc(%s)', newdesc)
  >         revs = repo.revs(query)
  >     return smartset.baseset(revs)
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > allowemptycommit=1
  > [extensions]
  > drawdag=$TESTDIR/drawdag.py
  > [phases]
  > publish=False
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} {desc} {instabilities}" -r 'sort(all(), topo)'
  > [extensions]
  > maprevset=$TESTTMP/maprevset.py
  > [experimental]
  > evolution=true
  > EOF

  $ rebasewithdag() {
  >   N=`"$PYTHON" -c "print($N+1)"`
  >   hg init repo$N && cd repo$N
  >   hg debugdrawdag
  >   hg rebase "$@" > _rebasetmp
  >   r=$?
  >   grep -v 'saved backup bundle' _rebasetmp
  >   [ $r -eq 0 ] && rm -f .hg/localtags && hg tglog
  >   cd ..
  >   return $r
  > }

Destination resolves to an empty set:

  $ rebasewithdag -s B -d 'SRC - SRC' <<'EOS'
  > C
  > |
  > B
  > |
  > A
  > EOS
  nothing to rebase - empty destination
  [1]

Multiple destinations and --collapse are not compatible:

  $ rebasewithdag -s C+E -d 'SRC^^' --collapse <<'EOS'
  > C F
  > | |
  > B E
  > | |
  > A D
  > EOS
  abort: --collapse does not work with multiple destinations
  [255]

Multiple destinations cannot be used with --base:

  $ rebasewithdag -b B+E -d 'SRC^^' --collapse <<'EOS'
  > B E
  > | |
  > A D
  > EOS
  abort: unknown revision 'SRC'!
  [255]

Rebase to null should work:

  $ rebasewithdag -r A+C+D -d 'null' <<'EOS'
  > C D
  > | |
  > A B
  > EOS
  already rebased 0:426bada5c675 "A" (A)
  already rebased 2:dc0947a82db8 "C" (C)
  rebasing 3:004dc1679908 "D" (D tip)
  o  4: d8d8601abd5e D
  
  o  2: dc0947a82db8 C
  |
  | o  1: fc2b737bb2e5 B
  |
  o  0: 426bada5c675 A
  
Destination resolves to multiple changesets:

  $ rebasewithdag -s B -d 'ALLSRC+SRC' <<'EOS'
  > C
  > |
  > B
  > |
  > Z
  > EOS
  abort: rebase destination for f0a671a46792 is not unique
  [255]

Destination is an ancestor of source:

  $ rebasewithdag -s B -d 'SRC' <<'EOS'
  > C
  > |
  > B
  > |
  > Z
  > EOS
  abort: source and destination form a cycle
  [255]

BUG: cycles aren't flagged correctly when --dry-run is set:
  $ rebasewithdag -s B -d 'SRC' --dry-run <<'EOS'
  > C
  > |
  > B
  > |
  > Z
  > EOS
  abort: source and destination form a cycle
  starting dry-run rebase; repository will not be changed
  [255]

Switch roots:

  $ rebasewithdag -s 'all() - roots(all())' -d 'roots(all()) - ::SRC' <<'EOS'
  > C  F
  > |  |
  > B  E
  > |  |
  > A  D
  > EOS
  rebasing 2:112478962961 "B" (B)
  rebasing 4:26805aba1e60 "C" (C)
  rebasing 3:cd488e83d208 "E" (E)
  rebasing 5:0069ba24938a "F" (F tip)
  o  9: d150ff263fc8 F
  |
  o  8: 66f30a1a2eab E
  |
  | o  7: 93db94ffae0e C
  | |
  | o  6: d0071c3b0c88 B
  | |
  | o  1: 058c1e1fb10a D
  |
  o  0: 426bada5c675 A
  
Different destinations for merge changesets with a same root:

  $ rebasewithdag -s B -d '((parents(SRC)-B-A)::) - (::ALLSRC)' <<'EOS'
  > C G
  > |\|
  > | F
  > |
  > B E
  > |\|
  > A D
  > EOS
  rebasing 3:a4256619d830 "B" (B)
  rebasing 6:8e139e245220 "C" (C tip)
  o    8: 51e2ce92e06a C
  |\
  | o    7: 2ed0c8546285 B
  | |\
  o | |  5: 8fdb2c1feb20 G
  | | |
  | | o  4: cd488e83d208 E
  | | |
  o | |  2: a6661b868de9 F
   / /
  | o  1: 058c1e1fb10a D
  |
  o  0: 426bada5c675 A
  
Move to a previous parent:

  $ rebasewithdag -s E+F+G -d 'SRC^^' <<'EOS'
  >     H
  >     |
  >   D G
  >   |/
  >   C F
  >   |/
  >   B E  # E will be ignored, since E^^ is empty
  >   |/
  >   A
  > EOS
  rebasing 4:33441538d4aa "F" (F)
  rebasing 6:cf43ad9da869 "G" (G)
  rebasing 7:eef94f3b5f03 "H" (H tip)
  o  10: b3d84c6666cf H
  |
  | o  5: f585351a92f8 D
  |/
  o  3: 26805aba1e60 C
  |
  | o  9: f7c28a1a15e2 G
  |/
  o  1: 112478962961 B
  |
  | o  8: 02aa697facf7 F
  |/
  | o  2: 7fb047a69f22 E
  |/
  o  0: 426bada5c675 A
  
Source overlaps with destination:

  $ rebasewithdag -s 'B+C+D' -d 'map(SRC, "B:C,C:D")' <<'EOS'
  > B C D
  >  \|/
  >   A
  > EOS
  rebasing 2:dc0947a82db8 "C" (C)
  rebasing 1:112478962961 "B" (B)
  o  5: 5fe9935d5222 B
  |
  o  4: 12d20731b9e0 C
  |
  o  3: b18e25de2cf5 D
  |
  o  0: 426bada5c675 A
  
Detect cycles early:

  $ rebasewithdag -r 'all()-Z' -d 'map(SRC, "A:B,B:C,C:D,D:B")' <<'EOS'
  > A B C
  >  \|/
  >   | D
  >   |/
  >   Z
  > EOS
  abort: source and destination form a cycle
  [255]

Detect source is ancestor of dest in runtime:

  $ rebasewithdag -r 'C+B' -d 'map(SRC, "C:B,B:D")' -q <<'EOS'
  >   D
  >   |
  > B C
  >  \|
  >   A
  > EOS
  abort: source is ancestor of destination
  [255]

"Already rebased" fast path still works:

  $ rebasewithdag -r 'all()' -d 'SRC^' <<'EOS'
  >   E F
  >  /| |
  > B C D
  >  \|/
  >   A
  > EOS
  already rebased 1:112478962961 "B" (B)
  already rebased 2:dc0947a82db8 "C" (C)
  already rebased 3:b18e25de2cf5 "D" (D)
  already rebased 4:312782b8f06e "E" (E)
  already rebased 5:ad6717a6a58e "F" (F tip)
  o  5: ad6717a6a58e F
  |
  o  3: b18e25de2cf5 D
  |
  | o    4: 312782b8f06e E
  | |\
  +---o  2: dc0947a82db8 C
  | |
  | o  1: 112478962961 B
  |/
  o  0: 426bada5c675 A
  
Massively rewrite the DAG:

  $ rebasewithdag -r 'all()' -d 'map(SRC, "A:I,I:null,H:A,B:J,J:C,C:H,D:E,F:G,G:K,K:D,E:B")' <<'EOS'
  > D G K
  > | | |
  > C F J
  > | | |
  > B E I
  >  \| |
  >   A H
  > EOS
  rebasing 4:701514e1408d "I" (I)
  rebasing 0:426bada5c675 "A" (A)
  rebasing 1:e7050b6e5048 "H" (H)
  rebasing 5:26805aba1e60 "C" (C)
  rebasing 7:cf89f86b485b "J" (J)
  rebasing 2:112478962961 "B" (B)
  rebasing 3:7fb047a69f22 "E" (E)
  rebasing 8:f585351a92f8 "D" (D)
  rebasing 10:ae41898d7875 "K" (K tip)
  rebasing 9:711f53bbef0b "G" (G)
  rebasing 6:64a8289d2492 "F" (F)
  o  21: 3735afb3713a F
  |
  o  20: 07698142d7a7 G
  |
  o  19: 33aba52e7e72 K
  |
  o  18: 9fdae89dc5a1 D
  |
  o  17: 277dda9a65ee E
  |
  o  16: 9c74fd8657ad B
  |
  o  15: 6527eb0688bb J
  |
  o  14: e94d655b928d C
  |
  o  13: 620d6d349459 H
  |
  o  12: a569a116758f A
  |
  o  11: 2bf1302f5c18 I
  
Resolve instability:

  $ rebasewithdag <<'EOF' -r 'orphan()-obsolete()' -d 'max((successors(max(roots(ALLSRC) & ::SRC)^)-obsolete())::)'
  >      F2
  >      |
  >    J E E2
  >    | |/
  > I2 I | E3
  >   \| |/
  >    H | G
  >    | | |
  >   B2 D F
  >    | |/         # rebase: B -> B2
  >    N C          # amend: E -> E2
  >    | |          # amend: E2 -> E3
  >    M B          # rebase: F -> F2
  >     \|          # amend: I -> I2
  >      A
  > EOF
  6 new orphan changesets
  rebasing 16:5c432343bf59 "J" (J tip)
  rebasing 3:26805aba1e60 "C" (C)
  rebasing 6:f585351a92f8 "D" (D)
  rebasing 10:ffebc37c5d0b "E3" (E3)
  rebasing 13:fb184bcfeee8 "F2" (F2)
  rebasing 11:dc838ab4c0da "G" (G)
  o  22: 174f63d574a8 G
  |
  o  21: c9d9fbe76705 F2
  |
  o  20: 0a03c2ede755 E3
  |
  o  19: 228d9d2541b1 D
  |
  o  18: cd856b400c95 C
  |
  o  17: 9148200c858c J
  |
  o  15: eb74780f5094 I2
  |
  o  12: 78309edd643f H
  |
  o  5: 4b4531bd8e1d B2
  |
  o  4: 337c285c272b N
  |
  o  2: 699bc4b6fa22 M
  |
  o  0: 426bada5c675 A