rebase: demonstrate bug in dry-run mode which causes cycles to not be reported

Differential Revision: https://phab.mercurial-scm.org/D6225

tests/test-rebase-dest.t

@@ -1,453 +1,465 b''
 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: no rebase in progress
+  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