view tests/test-rebase-abort.t @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

#testcases abortcommand abortflag
#testcases continuecommand continueflag

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}:{phase} '{desc}' {branches}\n"
  > EOF

#if abortflag
  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > abort = rebase --abort
  > EOF
#endif

#if continueflag
  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > continue = rebase --continue
  > EOF
#endif

  $ hg init a
  $ cd a

  $ touch .hg/rebasestate
  $ hg sum
  parent: -1:000000000000 tip (empty repository)
  branch: default
  commit: (clean)
  update: (current)
  abort: .hg/rebasestate is incomplete
  [255]
  $ rm .hg/rebasestate

  $ echo c1 > common
  $ hg add common
  $ hg ci -m C1

  $ echo c2 >> common
  $ hg ci -m C2

  $ echo c3 >> common
  $ hg ci -m C3

  $ hg up -q -C 1

  $ echo l1 >> extra
  $ hg add extra
  $ hg ci -m L1
  created new head

  $ sed -e 's/c2/l2/' common > common.new
  $ mv common.new common
  $ hg ci -m L2

  $ hg phase --force --secret 2

  $ hg tglog
  @  4:draft 'L2'
  |
  o  3:draft 'L1'
  |
  | o  2:secret 'C3'
  |/
  o  1:draft 'C2'
  |
  o  0:draft 'C1'
  

Conflicting rebase:

  $ hg rebase -s 3 -d 2
  rebasing 3:3163e20567cc "L1"
  rebasing 4:46f0b057b5c0 tip "L2"
  merging common
  warning: conflicts while merging common! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

Insert unsupported advisory merge record:

  $ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -x
  $ hg debugmergestate
  local (dest): 3e046f2ecedb793b97ed32108086edd1a162f8bc
  other (source): 46f0b057b5c061d276b91491c22151f78698abd2
  file: common (state "u")
    local path: common (hash 94c8c21d08740f5da9eaa38d1f175c592692f0d1, flags "")
    ancestor path: common (node de0a666fdd9c1a0b0698b90d85064d8bd34f74b6)
    other path: common (node 2f6411de53677f6f1048fef5bf888d67a342e0a5)
    extra: ancestorlinknode = 3163e20567cc93074fbb7a53c8b93312e59dbf2c
  $ hg resolve -l
  U common

Insert unsupported mandatory merge record:

  $ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -X
  $ hg debugmergestate
  abort: unsupported merge state records: X
  (see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
  [255]
  $ hg resolve -l
  abort: unsupported merge state records: X
  (see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
  [255]
  $ hg resolve -ma
  abort: unsupported merge state records: X
  (see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
  [255]

Abort (should clear out unsupported merge state):

#if abortcommand
when in dry-run mode
  $ hg abort --dry-run
  rebase in progress, will be aborted
#endif

  $ hg abort
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/3e046f2ecedb-6beef7d5-backup.hg
  rebase aborted
  $ hg debugmergestate
  no merge state found

  $ hg tglog
  @  4:draft 'L2'
  |
  o  3:draft 'L1'
  |
  | o  2:secret 'C3'
  |/
  o  1:draft 'C2'
  |
  o  0:draft 'C1'
  
Test safety for inconsistent rebase state, which may be created (and
forgotten) by Mercurial earlier than 2.7. This emulates Mercurial
earlier than 2.7 by renaming ".hg/rebasestate" temporarily.

  $ hg rebase -s 3 -d 2
  rebasing 3:3163e20567cc "L1"
  rebasing 4:46f0b057b5c0 tip "L2"
  merging common
  warning: conflicts while merging common! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

  $ mv .hg/rebasestate .hg/rebasestate.back
  $ hg update --quiet --clean 2
  $ hg --config extensions.mq= strip --quiet "destination()"
  $ mv .hg/rebasestate.back .hg/rebasestate

  $ hg continue
  abort: cannot continue inconsistent rebase
  (use "hg rebase --abort" to clear broken state)
  [255]
  $ hg summary | grep '^rebase: '
  rebase: (use "hg rebase --abort" to clear broken state)
  $ hg abort
  rebase aborted (no revision is removed, only broken state is cleared)

  $ cd ..


Construct new repo:

  $ hg init b
  $ cd b

  $ echo a > a
  $ hg ci -Am A
  adding a

  $ echo b > b
  $ hg ci -Am B
  adding b

  $ echo c > c
  $ hg ci -Am C
  adding c

  $ hg up -q 0

  $ echo b > b
  $ hg ci -Am 'B bis'
  adding b
  created new head

  $ echo c1 > c
  $ hg ci -Am C1
  adding c

  $ hg phase --force --secret 1
  $ hg phase --public 1

Rebase and abort without generating new changesets:

  $ hg tglog
  @  4:draft 'C1'
  |
  o  3:draft 'B bis'
  |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ hg rebase -b 4 -d 2
  rebasing 3:a6484957d6b9 "B bis"
  note: not rebasing 3:a6484957d6b9 "B bis", its destination already has all its changes
  rebasing 4:145842775fec tip "C1"
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

  $ hg tglog
  %  4:draft 'C1'
  |
  o  3:draft 'B bis'
  |
  | @  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ hg rebase -a
  rebase aborted

  $ hg tglog
  @  4:draft 'C1'
  |
  o  3:draft 'B bis'
  |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  

  $ cd ..

rebase abort should not leave working copy in a merge state if tip-1 is public
(issue4082)

  $ hg init abortpublic
  $ cd abortpublic
  $ echo a > a && hg ci -Aqm a
  $ hg book master
  $ hg book foo
  $ echo b > b && hg ci -Aqm b
  $ hg up -q master
  $ echo c > c && hg ci -Aqm c
  $ hg phase -p -r .
  $ hg up -q foo
  $ echo C > c && hg ci -Aqm C
  $ hg log -G --template "{rev} {desc} {bookmarks}"
  @  3 C foo
  |
  | o  2 c master
  | |
  o |  1 b
  |/
  o  0 a
  

  $ hg rebase -d master -r foo
  rebasing 3:6c0f977a22d8 foo tip "C"
  merging c
  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ hg abort
  rebase aborted
  $ hg log -G --template "{rev} {desc} {bookmarks}"
  @  3 C foo
  |
  | o  2 c master
  | |
  o |  1 b
  |/
  o  0 a
  
  $ cd ..

Make sure we don't clobber changes in the working directory when the
user has somehow managed to update to a different revision (issue4009)

  $ hg init noupdate
  $ cd noupdate
  $ hg book @
  $ echo original > a
  $ hg add a
  $ hg commit -m a
  $ echo x > b
  $ hg add b
  $ hg commit -m b1
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (leaving bookmark @)
  $ hg book foo
  $ echo y > b
  $ hg add b
  $ hg commit -m b2
  created new head

  $ hg rebase -d @ -b foo --tool=internal:fail
  rebasing 2:070cf4580bb5 foo tip "b2"
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

  $ mv .hg/rebasestate ./ # so we're allowed to hg up like in mercurial <2.6.3
  $ hg up -C 0            # user does other stuff in the repo
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ mv rebasestate .hg/   # user upgrades to 2.7

  $ echo new > a
  $ hg up 1               # user gets an error saying to run hg rebase --abort
  abort: rebase in progress
  (use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
  [20]

  $ cat a
  new
  $ hg abort
  rebase aborted
  $ cat a
  new

  $ cd ..

test aborting an interrupted series (issue5084)
  $ hg init interrupted
  $ cd interrupted
  $ touch base
  $ hg add base
  $ hg commit -m base
  $ touch a
  $ hg add a
  $ hg commit -m a
  $ echo 1 > a
  $ hg commit -m 1
  $ touch b
  $ hg add b
  $ hg commit -m b
  $ echo 2 >> a
  $ hg commit -m c
  $ touch d
  $ hg add d
  $ hg commit -m d
  $ hg co -q 1
  $ hg rm a
  $ hg commit -m no-a
  created new head
  $ hg co 0
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G --template "{rev} {desc} {bookmarks}"
  o  6 no-a
  |
  | o  5 d
  | |
  | o  4 c
  | |
  | o  3 b
  | |
  | o  2 1
  |/
  o  1 a
  |
  @  0 base
  
  $ hg --config extensions.n=$TESTDIR/failfilemerge.py rebase -s 3 -d tip
  rebasing 3:3a71550954f1 "b"
  rebasing 4:e80b69427d80 "c"
  abort: ^C
  [255]

New operations are blocked with the correct state message

  $ find .hg -name '*state' -prune | sort
  .hg/dirstate
  .hg/merge/state
  .hg/rebasestate
  .hg/undo.backup.dirstate
  .hg/undo.dirstate
  .hg/updatestate

  $ hg rebase -s 3 -d tip
  abort: rebase in progress
  (use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
  [20]
  $ hg up .
  abort: rebase in progress
  (use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
  [20]
  $ hg up -C .
  abort: rebase in progress
  (use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
  [20]

  $ hg graft 3
  abort: rebase in progress
  (use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
  [20]

  $ hg abort
  saved backup bundle to $TESTTMP/interrupted/.hg/strip-backup/3d8812cf300d-93041a90-backup.hg
  rebase aborted
  $ hg log -G --template "{rev} {desc} {bookmarks}"
  o  6 no-a
  |
  | o  5 d
  | |
  | o  4 c
  | |
  | o  3 b
  | |
  | o  2 1
  |/
  o  1 a
  |
  @  0 base
  
  $ hg summary
  parent: 0:df4f53cec30a 
   base
  branch: default
  commit: (clean)
  update: 6 new changesets (update)
  phases: 7 draft

  $ cd ..
On the other hand, make sure we *do* clobber changes whenever we
haven't somehow managed to update the repo to a different revision
during a rebase (issue4661)

  $ hg ini yesupdate
  $ cd yesupdate
  $ echo "initial data" > foo.txt
  $ hg add
  adding foo.txt
  $ hg ci -m "initial checkin"
  $ echo "change 1" > foo.txt
  $ hg ci -m "change 1"
  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo "conflicting change 1" > foo.txt
  $ hg ci -m "conflicting 1"
  created new head
  $ echo "conflicting change 2" > foo.txt
  $ hg ci -m "conflicting 2"

  $ hg rebase -d 1 --tool 'internal:fail'
  rebasing 2:e4ea5cdc9789 "conflicting 1"
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ hg abort
  rebase aborted
  $ hg summary
  parent: 3:b16646383533 tip
   conflicting 2
  branch: default
  commit: (clean)
  update: 1 new changesets, 2 branch heads (merge)
  phases: 4 draft
  $ cd ..

test aborting a rebase succeeds after rebasing with skipped commits onto a
public changeset (issue4896)

  $ hg init succeedonpublic
  $ cd succeedonpublic
  $ echo 'content' > root
  $ hg commit -A -m 'root' -q

set up public branch
  $ echo 'content' > disappear
  $ hg commit -A -m 'disappear public' -q
commit will cause merge conflict on rebase
  $ echo '' > root
  $ hg commit -m 'remove content public' -q
  $ hg phase --public

setup the draft branch that will be rebased onto public commit
  $ hg up -r 0 -q
  $ echo 'content' > disappear
commit will disappear
  $ hg commit -A -m 'disappear draft' -q
  $ echo 'addedcontADDEDentadded' > root
commit will cause merge conflict on rebase
  $ hg commit -m 'add content draft' -q

  $ hg rebase -d 'public()' --tool :merge -q
  note: not rebasing 3:0682fd3dabf5 "disappear draft", its destination already has all its changes
  warning: conflicts while merging root! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ hg abort
  rebase aborted
  $ cd ..