view tests/test-rebase-conflicts.t @ 25757:4d1382fd96ff

context: write dirstate out explicitly at the end of markcommitted

To detect change of a file without redundant comparison of file
content, dirstate recognizes a file as certainly clean, if:

  (1) it is already known as "normal",
  (2) dirstate entry for it has valid (= not "-1") timestamp, and
  (3) mode, size and timestamp of it on the filesystem are as same as
      ones expected in dirstate

This works as expected in many cases, but doesn't in the corner case
that changing a file keeps mode, size and timestamp of it on the
filesystem.

The timetable below shows steps in one of typical such situations:

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
   *                                             ***    ***
       - 'hg transplant REV1 REV2 ...'
         - transplanting REV1
           ....
   N
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - 'dirstate.normal("f")'          N   ***
             (via 'repo.commit()')

         - transplanting REV2
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - aborted while patching
  N+1
         - release wlock
           - 'dirstate.write()'              N    N      N

       - 'hg status' shows "r1" as "clean"   N    N      N
  ---- ----------------------------------- ---- ----- -----

The most important point is that 'dirstate.write()' is executed at N+1
or later. This causes writing dirstate timestamp N of "f" out
successfully. If it is executed at N, 'parsers.pack_dirstate()'
replaces timestamp N with "-1" before actual writing dirstate out.

This issue can occur when 'hg transplant' satisfies conditions below:

  - multiple revisions to be transplanted change the same file
  - those revisions don't change mode and size of the file, and
  - the 2nd or later revision of them fails after changing the file

The root cause of this issue is that files are changed without
flushing in-memory dirstate changes via 'repo.commit()' (even though
omitting 'dirstate.normallookup()' on files changed by 'patch.patch()'
for efficiency also causes this issue).

To detect changes of files correctly, this patch writes in-memory
dirstate changes out explicitly after marking files as clean in
'committablectx.markcommitted()', which is invoked via
'repo.commit()'.

After this change, timetable is changed as below:

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
   *                                             ***    ***
       - 'hg transplant REV1 REV2 ...'
         - transplanting REV1
           ....
   N
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - 'dirstate.normal("f")'          N    ***
             (via 'repo.commit()')
       ----------------------------------- ---- ----- -----
           - 'dirsttate.write()'            -1    -1
       ----------------------------------- ---- ----- -----
         - transplanting REV2
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - aborted while patching
  N+1
         - release wlock
           - 'dirstate.write()'              -1   -1     N

       - 'hg status' shows "r1" as "clean"   -1   -1     N
  ---- ----------------------------------- ---- ----- -----

To reproduce this issue in tests certainly, this patch emulates some
timing critical actions as below:

  - change "f" at N

    'patch.patch()' with 'fakepatchtime.py' explicitly changes mtime
    of patched files to "2000-01-01 00:00" (= N).

  - 'dirstate.write()' via 'repo.commit()' at N

    'fakedirstatewritetime.py' forces 'pack_dirstate()' to use
    "2000-01-01 00:00" as "now", only if 'pack_dirstate()' is invoked
    via 'committablectx.markcommitted()'.

  - 'dirstate.write()' via releasing wlock at N+1 (or "not at N")

    'pack_dirstate()' via releasing wlock uses actual timestamp at
    runtime as "now", and it should be different from the "2000-01-01
    00:00" of "f".

BTW, this patch doesn't test cases below, even though 'patch.patch()'
is used similarly in these cases:

  1. failure of 'hg import' or 'hg qpush'

  2. success of 'hg import', 'hg qpush' or 'hg transplant'

Case (1) above doesn't cause this kind of issue, because:

  - if patching is aborted by conflicts, changed files are committed

    changed files are marked as CLEAN, even though they are partially
    patched.

  - otherwise, dirstate are fully restored by 'dirstateguard'

    For example in timetable above, timestamp of "f" in .hg/dirstate
    is restored to -1 (or less than N), and subsequent 'hg status' can
    detect changes correctly.

Case (2) always causes 'repo.status()' invocation via 'repo.commit()'
just after changing files inside same wlock scope.

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
  N                                              ***   ***
       - make file "f" clean                            N

       - execute 'hg foobar'
         ....
         - 'dirstate.normal("f")'           N    ***
           (e.g. via dirty check
            or previous 'repo.commit()')

         - change "f", but keep size                    N
         - 'repo.status()' (*1)
           (via 'repo.commit()')
  ---- ----------------------------------- ---- ----- -----

At a glance, 'repo.status()' at (*1) seems to cause similar issue (=
"changed files are treated as clean"), but actually doesn't.

'dirstate._lastnormaltime' should be N at (*1) above, because
'dirstate.normal()' via dirty check is finished at N.

Therefore, "f" changed at N (= 'dirstate._lastnormaltime') is forcibly
treated as "unsure" at (*1), and changes are detected as expected (see
'dirstate.status()' for detail).

If 'hg import' is executed with '--no-commit', 'repo.status()' isn't
invoked just after changing files inside same wlock scope.

But preceding 'dirstate.normal()' is invoked inside another wlock
scope via 'cmdutil.bailifchanged()', and in-memory changes should be
flushed at the end of that scope.

Therefore, timestamp N of clean "f" should be replaced by -1, if
'dirstate.write()' is invoked at N. It means that condition of this
issue isn't satisfied.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [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 during merge.
  merging common incomplete! (edit conflicts, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Try to continue without solving the conflict:

  $ hg rebase --continue
  already rebased 3:3163e20567cc "L1" as 3e046f2ecedb
  rebasing 4:46f0b057b5c0 "L2"
  abort: unresolved merge conflicts (see "hg help resolve")
  [255]

Conclude rebase:

  $ echo 'resolved merge' >common
  $ hg resolve -m common
  (no more unresolved files)
  $ 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-backup.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)
  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 2 starting from e31216eec445
  ignoring null merge rebase of 3
  ignoring null merge rebase of 4
  ignoring null merge rebase of 6
  ignoring null merge rebase of 8
  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
  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
  rebased as 19c888675e13
  rebasing 10:2f2496ddf49d "merge" (tip)
   future parents are 11 and 7
  rebase status stored
   already in target
   merge against 10:2f2496ddf49d
     detach base 9:e31216eec445
    searching for copies back to rev 3
  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
  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
  saved backup bundle to $TESTTMP/issue4041/.hg/strip-backup/e31216eec445-15f7a814-backup.hg (glob)
  3 changesets found
  list of changesets:
  4c9fbe56a16f30c0d5dcc40ec1a97bbe3325209c
  19c888675e133ab5dff84516926a65672eaf04d9
  2a7f09cac94c7f4b73ebd5cd1a62d3b2e8e336bf
  adding branch
  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
  invalid branchheads cache (served): tip differs
  rebase completed
  updating the branch cache
  truncating cache/rbc-revs-v1 to 72