view tests/test-rebase-conflicts.t @ 35121:66c5a8cf2868

lfs: import the Facebook git-lfs client extension

The purpose of this is the same as the built-in largefiles extension- to handle
huge files outside of the normal storage system, generally to keep the amount of
data cloned to a lower amount.  There are several benefits of implementing the
git-lfs protocol, instead of using the largefiles extension:

  - Bitbucket and Github support (and probably wider support in 3rd party
    hosting sites in general). [1][2]

  - The number of hg internals monkey patched are several orders of magnitude
    lower, so it will be easier to reason about and maintain.  Future commands
    will likely just work, without requiring various wrappers.

  - The "standin" files are only written to the filelog, not the disk.  That
    should avoid weird edge cases where the largefile and standin files get out
    of sync. [3]  It also avoids the occasional printing of the "hidden" standin
    file in various messages.

  - Filesets like size() will work, even if the file isn't present.  (It always
    says 41 bytes for largefiles, whether present or not.)

The only place that I see where largefiles comes out on top is that it works
with `hg serve` for simple sharing, without external infrastructure.  Getting
lfs-test-server working was a hassle, and took awhile to figure out.  Maybe we
can do something to make it work in the future.

Long term, I expect that this will be highly preferred over largefiles.  But if
we are to recommend this to largefile users, there are some UI issues to
bikeshed.  Until they are resolved, I've marked this experimental, and am not
putting a pointer to this in the largefiles help.  The (non exhaustive) list of
issues I've seen so far are:

  - It isn't sufficient to just enable the largefiles extension- you have to
    explicitly add a file with --large before it will pay attention to the
    configured sizes and patterns on future adds.  The justification being that
    once you use it, you're stuck with it.  I've seen people confused by this,
    and haven't liked it myself.  But it's also saved me a few times.  Should we
    do something like have a specific enabling config setting that must be set
    in the local repo config, so that enabling this extension in the user or
    system hgrc doesn't silently start storing lfs files?

  - The largefiles extension adds a repo requirement when the first largefile is
    committed, so that the extension must always be enabled in the future.  This
    extension is not doing that, and since I only enabled it locally to avoid
    infecting other repos, I got a cryptic error about missing flag processors
    when I cloned.  Is there no repo requirement due to shallow/narrow clone
    considerations (or other future advanced things)?

  - In the (small amount of) reading I've done about the git implementation, it
    seems that the files and sizes are stored in a tracked .gitattributes file.
    I think a tracked file for this would be extremely useful for consistency
    across developers, but this kind of touches on the tracked hgrc file
    proposal a few months back.

  - The git client can specify file patterns, not just sizes.

  - The largefiles extension has a cache directory in the local repo, but also a
    system wide one.  We should probably implement a system wide cache too, so
    that multiple clones don't have to refetch the files from the server.

  - Jun mentioned other missing features, like SSH authentication, gc, etc.

The code corresponds to c0492b73c7ef in hg-experimental. [4]  The only tweaks
are to load the extension in the tests with 'lfs=' instead of
'lfs=$TESTDIR/../hgext3rd/lfs', change the import in the *.py test to hgext
(from hgext3rd), add the 'testedwith' declaration, and mark it experimental for
now.  The infinite-push, p4fastimport, and remotefilelog tests were left behind.

The devel-warnings for unregistered config options are not corrected yet, nor
are the import check warnings.

[1] https://www.mercurial-scm.org/pipermail/mercurial/2017-November/050699.html
[2] https://bitbucket.org/site/master/issues/3843/largefiles-support-bb-3903
[3] https://bz.mercurial-scm.org/show_bug.cgi?id=5738
[4] https://bitbucket.org/facebook/hg-experimental

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

  $ hg init a
  $ cd a
  $ 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

  $ echo l3 >> extra2
  $ hg add extra2
  $ hg ci -m L3
  $ hg bookmark mybook

  $ hg phase --force --secret 4

  $ hg tglog
  @  5:secret 'L3'  mybook
  |
  o  4:secret 'L2'
  |
  o  3:draft 'L1'
  |
  | o  2:draft 'C3'
  |/
  o  1:draft 'C2'
  |
  o  0:draft 'C1'
  
Try to call --continue:

  $ hg rebase --continue
  abort: no rebase in progress
  [255]

Conflicting rebase:

  $ hg rebase -s 3 -d 2
  rebasing 3:3163e20567cc "L1"
  rebasing 4:46f0b057b5c0 "L2"
  merging common
  warning: conflicts while merging common! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ hg status --config commands.status.verbose=1
  M common
  ? common.orig
  # The repository is in an unfinished *rebase* state.
  
  # Unresolved merge conflicts:
  # 
  #     common
  # 
  # To mark files as resolved:  hg resolve --mark FILE
  
  # To continue:                hg rebase --continue
  # To abort:                   hg rebase --abort
  

Try to continue without solving the conflict:

  $ hg rebase --continue
  abort: unresolved merge conflicts (see 'hg help resolve')
  [255]

Conclude rebase:

  $ echo 'resolved merge' >common
  $ hg resolve -m common
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  already rebased 3:3163e20567cc "L1" as 3e046f2ecedb
  rebasing 4:46f0b057b5c0 "L2"
  rebasing 5:8029388f38dc "L3" (mybook)
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/3163e20567cc-5ca4656e-rebase.hg (glob)

  $ hg tglog
  @  5:secret 'L3'  mybook
  |
  o  4:secret 'L2'
  |
  o  3:draft 'L1'
  |
  o  2:draft 'C3'
  |
  o  1:draft 'C2'
  |
  o  0:draft 'C1'
  
Check correctness:

  $ hg cat -r 0 common
  c1

  $ hg cat -r 1 common
  c1
  c2

  $ hg cat -r 2 common
  c1
  c2
  c3

  $ hg cat -r 3 common
  c1
  c2
  c3

  $ hg cat -r 4 common
  resolved merge

  $ hg cat -r 5 common
  resolved merge

Bookmark stays active after --continue
  $ hg bookmarks
   * mybook                    5:d67b21408fc0

  $ cd ..

Check that the right ancestors is used while rebasing a merge (issue4041)

  $ hg clone "$TESTDIR/bundles/issue4041.hg" issue4041
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 11 changesets with 8 changes to 3 files (+1 heads)
  new changesets 24797d4f68de:2f2496ddf49d
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd issue4041
  $ hg log -G
  o    changeset:   10:2f2496ddf49d
  |\   branch:      f1
  | |  tag:         tip
  | |  parent:      7:4c9fbe56a16f
  | |  parent:      9:e31216eec445
  | |  user:        szhang
  | |  date:        Thu Sep 05 12:59:39 2013 -0400
  | |  summary:     merge
  | |
  | o  changeset:   9:e31216eec445
  | |  branch:      f1
  | |  user:        szhang
  | |  date:        Thu Sep 05 12:59:10 2013 -0400
  | |  summary:     more changes to f1
  | |
  | o    changeset:   8:8e4e2c1a07ae
  | |\   branch:      f1
  | | |  parent:      2:4bc80088dc6b
  | | |  parent:      6:400110238667
  | | |  user:        szhang
  | | |  date:        Thu Sep 05 12:57:59 2013 -0400
  | | |  summary:     bad merge
  | | |
  o | |  changeset:   7:4c9fbe56a16f
  |/ /   branch:      f1
  | |    parent:      2:4bc80088dc6b
  | |    user:        szhang
  | |    date:        Thu Sep 05 12:54:00 2013 -0400
  | |    summary:     changed f1
  | |
  | o  changeset:   6:400110238667
  | |  branch:      f2
  | |  parent:      4:12e8ec6bb010
  | |  user:        szhang
  | |  date:        Tue Sep 03 13:58:02 2013 -0400
  | |  summary:     changed f2 on f2
  | |
  | | @  changeset:   5:d79e2059b5c0
  | | |  parent:      3:8a951942e016
  | | |  user:        szhang
  | | |  date:        Tue Sep 03 13:57:39 2013 -0400
  | | |  summary:     changed f2 on default
  | | |
  | o |  changeset:   4:12e8ec6bb010
  | |/   branch:      f2
  | |    user:        szhang
  | |    date:        Tue Sep 03 13:57:18 2013 -0400
  | |    summary:     created f2 branch
  | |
  | o  changeset:   3:8a951942e016
  | |  parent:      0:24797d4f68de
  | |  user:        szhang
  | |  date:        Tue Sep 03 13:57:11 2013 -0400
  | |  summary:     added f2.txt
  | |
  o |  changeset:   2:4bc80088dc6b
  | |  branch:      f1
  | |  user:        szhang
  | |  date:        Tue Sep 03 13:56:20 2013 -0400
  | |  summary:     added f1.txt
  | |
  o |  changeset:   1:ef53c9e6b608
  |/   branch:      f1
  |    user:        szhang
  |    date:        Tue Sep 03 13:55:26 2013 -0400
  |    summary:     created f1 branch
  |
  o  changeset:   0:24797d4f68de
     user:        szhang
     date:        Tue Sep 03 13:55:08 2013 -0400
     summary:     added default.txt
  
  $ hg rebase -s9 -d2 --debug # use debug to really check merge base used
  rebase onto 4bc80088dc6b starting from e31216eec445
  rebase status stored
  rebasing 9:e31216eec445 "more changes to f1"
   future parents are 2 and -1
  rebase status stored
   update to 2:4bc80088dc6b
  resolving manifests
   branchmerge: False, force: True, partial: False
   ancestor: d79e2059b5c0+, local: d79e2059b5c0+, remote: 4bc80088dc6b
   f2.txt: other deleted -> r
  removing f2.txt
   f1.txt: remote created -> g
  getting f1.txt
   merge against 9:e31216eec445
     detach base 8:8e4e2c1a07ae
    searching for copies back to rev 3
    unmatched files in other (from topological common ancestor):
     f2.txt
  resolving manifests
   branchmerge: True, force: True, partial: False
   ancestor: 8e4e2c1a07ae, local: 4bc80088dc6b+, remote: e31216eec445
   f1.txt: remote is newer -> g
  getting f1.txt
  committing files:
  f1.txt
  committing manifest
  committing changelog
  updating the branch cache
  rebased as 19c888675e13
  rebasing 10:2f2496ddf49d "merge" (tip)
   future parents are 11 and 7
  rebase status stored
   already in destination
   merge against 10:2f2496ddf49d
     detach base 9:e31216eec445
    searching for copies back to rev 3
    unmatched files in other (from topological common ancestor):
     f2.txt
  resolving manifests
   branchmerge: True, force: True, partial: False
   ancestor: e31216eec445, local: 19c888675e13+, remote: 2f2496ddf49d
   f1.txt: remote is newer -> g
  getting f1.txt
  committing files:
  f1.txt
  committing manifest
  committing changelog
  updating the branch cache
  rebased as 2a7f09cac94c
  rebase merging completed
  update back to initial working directory parent
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 2a7f09cac94c, local: 2a7f09cac94c+, remote: d79e2059b5c0
   f1.txt: other deleted -> r
  removing f1.txt
   f2.txt: remote created -> g
  getting f2.txt
  2 changesets found
  list of changesets:
  e31216eec445e44352c5f01588856059466a24c9
  2f2496ddf49d69b5ef23ad8cf9fb2e0e4faf0ac2
  bundle2-output-bundle: "HG20", (1 params) 2 parts total
  bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
  bundle2-output-part: "phase-heads" 24 bytes payload
  saved backup bundle to $TESTTMP/issue4041/.hg/strip-backup/e31216eec445-15f7a814-rebase.hg (glob)
  3 changesets found
  list of changesets:
  4c9fbe56a16f30c0d5dcc40ec1a97bbe3325209c
  19c888675e133ab5dff84516926a65672eaf04d9
  2a7f09cac94c7f4b73ebd5cd1a62d3b2e8e336bf
  bundle2-output-bundle: "HG20", 2 parts total
  bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
  bundle2-output-part: "phase-heads" 24 bytes payload
  adding branch
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "changegroup" (params: 1 mandatory 1 advisory) supported
  adding changesets
  add changeset 4c9fbe56a16f
  add changeset 19c888675e13
  add changeset 2a7f09cac94c
  adding manifests
  adding file changes
  adding f1.txt revisions
  added 2 changesets with 2 changes to 1 files
  bundle2-input-part: total payload size 1686
  bundle2-input-part: "phase-heads" supported
  bundle2-input-part: total payload size 24
  bundle2-input-bundle: 1 parts total
  updating the branch cache
  invalid branchheads cache (served): tip differs
  rebase completed

Test minimization of merge conflicts
  $ hg up -q null
  $ echo a > a
  $ hg add a
  $ hg commit -q -m 'a'
  $ echo b >> a
  $ hg commit -q -m 'ab'
  $ hg bookmark ab
  $ hg up -q '.^'
  $ echo b >> a
  $ echo c >> a
  $ hg commit -q -m 'abc'
  $ hg rebase -s 7bc217434fc1 -d ab --keep
  rebasing 13:7bc217434fc1 "abc" (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 diff
  diff -r 328e4ab1f7cc a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	* (glob)
  @@ -1,2 +1,6 @@
   a
   b
  +<<<<<<< dest:   328e4ab1f7cc ab - test: ab
  +=======
  +c
  +>>>>>>> source: 7bc217434fc1 - test: abc
  $ hg rebase --abort
  rebase aborted
  $ hg up -q -C 7bc217434fc1
  $ hg rebase -s . -d ab --keep -t internal:merge3
  rebasing 13:7bc217434fc1 "abc" (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 diff
  diff -r 328e4ab1f7cc a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	* (glob)
  @@ -1,2 +1,8 @@
   a
  +<<<<<<< dest:   328e4ab1f7cc ab - test: ab
   b
  +||||||| base
  +=======
  +b
  +c
  +>>>>>>> source: 7bc217434fc1 - test: abc

Test rebase with obsstore turned on and off (issue5606)

  $ cd $TESTTMP
  $ hg init b
  $ cd b
  $ hg debugdrawdag <<'EOS'
  > D
  > |
  > C
  > |
  > B E
  > |/
  > A
  > EOS

  $ hg update E -q
  $ echo 3 > B
  $ hg commit --amend -m E -A B -q
  $ hg rebase -r B+D -d . --config experimental.evolution=true
  rebasing 1:112478962961 "B" (B)
  merging B
  warning: conflicts while merging B! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ echo 4 > B
  $ hg resolve -m
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue --config experimental.evolution=none
  rebasing 1:112478962961 "B" (B)
  rebasing 3:f585351a92f8 "D" (D)
  warning: orphaned descendants detected, not stripping 112478962961
  saved backup bundle to $TESTTMP/b/.hg/strip-backup/f585351a92f8-e536a9e4-rebase.hg (glob)

  $ rm .hg/localtags
  $ hg tglog
  o  5:draft 'D'
  |
  o  4:draft 'B'
  |
  @  3:draft 'E'
  |
  | o  2:draft 'C'
  | |
  | o  1:draft 'B'
  |/
  o  0:draft 'A'