view tests/test-rebase-mq-skip.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.

This emulates the effects of an hg pull --rebase in which the remote repo
already has one local mq patch

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


  $ hg init a
  $ cd a
  $ hg qinit -c

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

  $ echo r1 > r1
  $ hg add r1
  $ hg ci -m R1

  $ hg up -q 0

  $ hg qnew p0.patch -d '1 0'
  $ echo p0 > p0
  $ hg add p0
  $ hg qref -m P0

  $ hg qnew p1.patch -d '2 0'
  $ echo p1 > p1
  $ hg add p1
  $ hg qref -m P1

  $ hg export qtip > p1.patch

  $ hg up -q -C 1

  $ hg import p1.patch
  applying p1.patch

  $ rm p1.patch

  $ hg up -q -C qtip

  $ hg rebase -v
  rebasing 2:13a46ce44f60 "P0" (p0.patch qbase)
  resolving manifests
  removing p0
  getting r1
  resolving manifests
  getting p0
  committing files:
  p0
  committing manifest
  committing changelog
  rebasing 3:148775c71080 "P1" (p1.patch qtip)
  resolving manifests
  note: rebase of 3:148775c71080 created no changes to commit
  rebase merging completed
  updating mq patch p0.patch to 5:9ecc820b1737
  $TESTTMP/a/.hg/patches/p0.patch (glob)
  2 changesets found
  uncompressed size of bundle content:
       344 (changelog)
       284 (manifests)
       109  p0
       109  p1
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/13a46ce44f60-5da6ecfb-backup.hg (glob)
  2 changesets found
  uncompressed size of bundle content:
       399 (changelog)
       284 (manifests)
       109  p0
       109  p1
  adding branch
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  rebase completed
  1 revisions have been skipped

  $ hg tglog
  @  3: 'P0' tags: p0.patch qbase qtip tip
  |
  o  2: 'P1' tags: qparent
  |
  o  1: 'R1' tags:
  |
  o  0: 'C1' tags:
  
  $ cd ..


  $ hg init b
  $ cd b
  $ hg qinit -c

  $ for i in r0 r1 r2 r3 r4 r5 r6;
  > do
  >     echo $i > $i
  >     hg ci -Am $i
  > done
  adding r0
  adding r1
  adding r2
  adding r3
  adding r4
  adding r5
  adding r6

  $ hg qimport -r 1:tip

  $ hg up -q 0

  $ for i in r1 r3 r7 r8;
  > do
  >     echo $i > $i
  >     hg ci -Am branch2-$i
  > done
  adding r1
  created new head
  adding r3
  adding r7
  adding r8

  $ echo somethingelse > r4
  $ hg ci -Am branch2-r4
  adding r4

  $ echo r6 > r6
  $ hg ci -Am branch2-r6
  adding r6

  $ hg up -q qtip

  $ HGMERGE=internal:fail hg rebase
  rebasing 1:b4bffa6e4776 "r1" (1.diff qbase)
  note: rebase of 1:b4bffa6e4776 created no changes to commit
  rebasing 2:c0fd129beb01 "r2" (2.diff)
  rebasing 3:6ff5b8feed8e "r3" (3.diff)
  note: rebase of 3:6ff5b8feed8e created no changes to commit
  rebasing 4:094320fec554 "r4" (4.diff)
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ HGMERGE=internal:local hg resolve --all
  (no more unresolved files)

  $ hg rebase --continue
  already rebased 1:b4bffa6e4776 "r1" (1.diff qbase) as 057f55ff8f44
  already rebased 2:c0fd129beb01 "r2" (2.diff) as 1660ab13ce9a
  already rebased 3:6ff5b8feed8e "r3" (3.diff) as 1660ab13ce9a
  rebasing 4:094320fec554 "r4" (4.diff)
  note: rebase of 4:094320fec554 created no changes to commit
  rebasing 5:681a378595ba "r5" (5.diff)
  rebasing 6:512a1f24768b "r6" (6.diff qtip)
  note: rebase of 6:512a1f24768b created no changes to commit
  saved backup bundle to $TESTTMP/b/.hg/strip-backup/b4bffa6e4776-b9bfb84d-backup.hg (glob)

  $ hg tglog
  @  8: 'r5' tags: 5.diff qtip tip
  |
  o  7: 'r2' tags: 2.diff qbase
  |
  o  6: 'branch2-r6' tags: qparent
  |
  o  5: 'branch2-r4' tags:
  |
  o  4: 'branch2-r8' tags:
  |
  o  3: 'branch2-r7' tags:
  |
  o  2: 'branch2-r3' tags:
  |
  o  1: 'branch2-r1' tags:
  |
  o  0: 'r0' tags:
  

  $ cd ..